#6 NM wire in 1/2" hole?

[milli...@yahoo.com]

Hi,
I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.
My main panel doesn't seem to have any spare (unoccupied) 3/4" size punch outs left; but there is a 1/2" punch out. It is possible for me to fit this 6-3 with ground in there, but does anyone know whether this is prohibited by the NEC?
All advice (and NEC references) appreciated!
Regards,
Theodore.

[Doug Miller]

milli...@yahoo.com wrote in
news:1742115a-be05-4253...@googlegroups.com:

I doubt very much that this would meet Code. First of all, you can't just pass the cable
through the knockout hole -- for the protection of the cable and the connections, Code
requires some sort of fitting on the hole (e.g. a cable clamp aka "Romex connector") which
secures the cable to the box. And I can't imagine that any fitting which would fit a 1/2"
knockout is listed for use with anything as large as 6-3; for example, the Romex connectors
used with 1/2" knockouts are listed for 14-2 through 10-3.

Does the panel have any vacant 1" knockouts? Or can you ream the 1/2" hole to 3/4"?

[Tony Hwang]

Hi.
The length of cable must be long, otherwise wouldn't 8-3 do? Enlarging
hole is easy using rimmer, cabinet is not really heavy gauge steel.

[trader_4]

Aside from that, does he really need #6 for an AC? Presumbably a home AC?
I have a 5 ton, which I believe is the largest made and it's rated for #8. I
wonder if he's sizing based on breaker, instead of sizing based on the
install instructions and eqpt rating. Meaning I have a 50 amp breaker on
my 8 gauge, 5 ton and it's to code because it's a motor load, not an oven.

[philo]

On 07/21/2014 06:43 PM, gfre...@aol.com wrote:

> Get one of these
>
> http://www.harborfreight.com/knockout-punch-kit-91201.html
>
>



I agree, I'd punch it out.



(sorry if you got an email, I hit the wrong button)

[cl...@snyder.on.ca]

On Mon, 21 Jul 2014 15:30:28 -0700 (PDT), milli...@yahoo.com wrote:

Can you get the 6-3 cable through the required cable connector, is
the big question. If you can fit the 6-3 into the connector that
threads into the 1/2" knockout, you are gold. If not you will need a
knockout punch to enlarge the hole to 3/4" size (Greenlee punch)

[cl...@snyder.on.ca]

On Mon, 21 Jul 2014 17:23:30 -0600, Tony Hwang <drag...@shaw.ca>
wrote:

I assume you mean a reamer - which leaves all kinds of conductive
swarf all through the panel. The only RIGHT way to do it is with a
"knoclut punch" - aften referred to by the most common brand - a
"greenlee punch" Any electrician worth his salt will have one. All you
get that way is a metal ring.

[cl...@snyder.on.ca]

On Mon, 21 Jul 2014 19:43:33 -0400, gfre...@aol.com wrote:

>On Mon, 21 Jul 2014 15:30:28 -0700 (PDT), milli...@yahoo.com wrote:
>

>Get one of these
>
>http://www.harborfreight.com/knockout-punch-kit-91201.html
>

That will do the job. Wouldn't want to make my living with it, but it
will make a few holes, for sure. A lot cheaper than Greenlee

[Doug Miller]

Tony Hwang <drag...@shaw.ca> wrote in news:bihzv.65595$AN6....@fx01.iad:

> The length of cable must be long, otherwise wouldn't 8-3 do?

Conductor size is determined by amperage, not by length.

> Enlarging hole is easy using rimmer,

LMAO! The tool he needs is a *reamer*. A "rimmer" is something altogether different.

[Doug Miller]

trader_4 <tra...@optonline.net> wrote in news:33f37dfc-9d21-481f-9d0e-b98ec7ca68b6
@googlegroups.com:

> Aside from that, does he really need #6 for an AC? Presumbably a home AC?
> I have a 5 ton, which I believe is the largest made and it's rated for #8. I
> wonder if he's sizing based on breaker, instead of sizing based on the
> install instructions and eqpt rating. Meaning I have a 50 amp breaker on
> my 8 gauge, 5 ton and it's to code because it's a motor load, not an oven.

Whether he needs AWG-6 or AWG-8 is not really relevant -- neither one is listed for use with
any Romex connector or clamp that I'm aware of which will fit in a 1/2" knockout.

Another question for the OP: do you really need 6-3 (or 8-3, as the case may be) for an air
conditioner? If it's central AC, it's almost surely a pure 240V load, and 2-conductor cable will do
-- and if it's a window AC, 10-3 is almost surely sufficient.

[Doug Miller]

cl...@snyder.on.ca wrote in news:stbrs990vnsf901p0...@4ax.com:

> On Mon, 21 Jul 2014 15:30:28 -0700 (PDT), milli...@yahoo.com wrote:
>
>>Hi,
>>I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.
>>My main panel doesn't seem to have any spare (unoccupied) 3/4" size punch outs left;
but there is a 1/2" punch out. It is possible for me to fit this 6-3 with ground in there, but does
anyone know whether this is prohibited by the NEC?
>>All advice (and NEC references) appreciated!

> Can you get the 6-3 cable through the required cable connector, is
> the big question. If you can fit the 6-3 into the connector that
> threads into the 1/2" knockout, you are gold.

WRONG. The big question is whether the required cable connector is listed for use with 6-3
cable. If the connector is not listed for use with 6-3 cable, it's a Code violation to use it for
that, whether the cable fits or not.

[Father Guido Sarducci]

On 07/21/2014 06:30 PM, milli...@yahoo.com wrote:
> Hi,
> I'm running a 6-3 Romex NM-B with ground for my new air conditioner system.

That must be one bad ass air conditioner. Wouldn't want your electric bill.

[cl...@snyder.on.ca]

Wire size is PRIMARILY dictated by load, but cable length comes into
play due to excessive voltage drop. You can never go wrong going one
size oversized.

[cl...@snyder.on.ca]

Well, you show me a romex connector that will take a 6/3 cable that
isn't listed for use with 6/3 and you may have a point. The POINT is,
there is no romex connector that WILL accept a 6/3 - listed or not..

[cl...@snyder.on.ca]

On Mon, 21 Jul 2014 22:19:30 -0400, cl...@snyder.on.ca wrote:
I missed the 1/2" requirement in my last reply - this is the corrected
reply.

>>
>>> Can you get the 6-3 cable through the required cable connector, is
>>> the big question. If you can fit the 6-3 into the connector that
>>> threads into the 1/2" knockout, you are gold.
>>
>>WRONG. The big question is whether the required cable connector is listed for use with 6-3
>>cable. If the connector is not listed for use with 6-3 cable, it's a Code violation to use it for
>>that, whether the cable fits or not.

> Well, you show me a 1/2 inch romex connector that will take a 6/3 cable that

>isn't listed for use with 6/3 and you may have a point. The POINT is,

>there is no romex connector that WILL accept a 6/3 AND fit a 1/2" hole - listed or not..

[milli...@yahoo.com]

Hi, I'm the OP.
Yes, the mini split a/c system specs explicitly call for a 50amp breaker and #6 AWG (although I shudder to think that it'll actually use that much, with a 16 SEER).

I think I answered my own question by finding several "conduit fill charts" online that say 1/2" conduit can only have 2 #6 wires, so rules are there to keep me safe and I'm fine with that.

I also failed to notice one last 3/4" knock-out, so I'll be using that one.
Many thanks to all the good technical solutions and suggestions!
Regards,
Theodore.

[Stormin Mormon]

On a practical note, I'd be sure to have a Romex
connector

http://www.contractcleanersupplies.com/Merchant5/graphics/full-size/romex-connector.jpg
in the punch out. Just to run the wire through the
hole leaves the risk of the panel metal wearing
through the insulation and causing a short.

How many tons of cooling? I remember using 10 AWG
for 2 1/2 ton system one time.


--
.
Christopher A. Young
Learn about Jesus
www.lds.org
.

[Stormin Mormon]

On 7/21/2014 8:31 PM, cl...@snyder.on.ca wrote:
>> The length of cable must be long, otherwise wouldn't 8-3 do? Enlarging
>> hole is easy using rimmer, cabinet is not really heavy gauge steel.
> I assume you mean a reamer - which leaves all kinds of conductive
> swarf all through the panel. The only RIGHT way to do it is with a
> "knoclut punch" - aften referred to by the most common brand - a
> "greenlee punch" Any electrician worth his salt will have one. All you
> get that way is a metal ring.
>

HF sells step bits which can be used to enlarge
the hole. Of course, you need a shopvac in action
at the same time to catch the chips.

Instead of a rimmer, use a knoclut punch. Amazing,
one good misssspelled word desserves anothher.

[Stormin Mormon]

So, what's the tons or BTU that
needs such a big wire?

[trader_4]

I think Gfre might be on to something when he suggested it might
also have resistance electric heat and maybe that's why the need
for #6. If the OP gives the make and model we could probably find
the specs and install intructions and I'd like to take a look.
I'm still skeptical that a mini-split could really need #6. As I said,
my 5 ton central AC uses #8, but being AC only, it doesn't have any
resistance heat.

[Stormin Mormon]

On 7/22/2014 8:37 AM, trader_4 wrote:
> I think Gfre might be on to something when he suggested it might
> also have resistance electric heat and maybe that's why the need
> for #6. If the OP gives the make and model we could probably find
> the specs and install intructions and I'd like to take a look.
> I'm still skeptical that a mini-split could really need #6. As I said,
> my 5 ton central AC uses #8, but being AC only, it doesn't have any
> resistance heat.
>

OP had been providing some info, but now
I sense some resistance. We'll have to amp
it up a bit.

[philo]

Though your A/C is not likely to draw anywhere near 50 amps
continuously, it will have a very high initial startup current.

By using #6 wire the voltage drop should be minimal.

[HerHusband]

Hi Theodore,

> I'm running a 6-3 Romex NM-B with ground for my new air conditioner
> system. My main panel doesn't seem to have any spare (unoccupied) 3/4"
> size punch outs left; but there is a 1/2" punch out. It is possible
> for me to fit this 6-3 with ground in there, but does anyone know
> whether this is prohibited by the NEC?

You can enlarge the 1/2" punch outs to accept a 3/4" cable clamp.

The ideal way to do this is with a knockout punch, but they tend to be
rather expensive for a one time job. Step drills will also work, but
they're almost as expensive as a knockout punch.

I went through this recently with my garage heater and used a metal nibbler
to enlarge the hole. You can see photos on this page ("Relocating the power
cord" about halfway down the page):

http://www.watsondiy.com/heater.htm

Be sure to turn off the main breaker before you start working in the panel,
and vacuum up any little metal bits that may fall inside the panel.

Good luck!

Anthony Watson
www.mountainsoftware.com
www.watsondiy.com

[trader_4]

It's also minimal with #8 and the percent voltage drop difference
between #6 and #8 is insignificant. Which is why you can wire even a
5 ton AC with number #8.

[Doug Miller]

cl...@snyder.on.ca wrote in news:aolrs9pq0bt6sdphm...@4ax.com:

> On Mon, 21 Jul 2014 22:19:30 -0400, cl...@snyder.on.ca wrote:
> I missed the 1/2" requirement in my last reply - this is the corrected
> reply.

That's not all you missed, and no, your reply is not corrected, it's still wrong because you're
still missing the main point that whether the cable physically fits or not is meaningless. The
ONLY thing that counts is whether the connector is listed for such use.

The main reason for emphasizing the distinction is so that newbies are not mislead by your
incorrect post into thinking that -- for example -- because they can fit three 14-2 cables in a
standard Romex connector it must be OK to do so.

[Doug Miller]

milli...@yahoo.com wrote in
news:16518db6-654b-409b...@googlegroups.com:

> Hi, I'm the OP.
> Yes, the mini split a/c system specs explicitly call for a 50amp
> breaker and #6 AWG (although I shudder to think that it'll
> actually use that much, with a 16 SEER).

Do you really need 6-3 cable, though? Or will 6-2 suffice?

[trader_4]

Another good point. Would be a shame to pay for 3 conductors and then
wind up not even having a place to connect one. I'd be curious to learn
the make/model of this beast so we can see the install instructions. I'm
still skeptical of 6 gauge for a mini-split.

[philo]

On 07/22/2014 09:42 AM, trader_4 wrote:
>
>>>
>>
>>
>>
>>
>>
>>
>>
>> Though your A/C is not likely to draw anywhere near 50 amps
>>
>> continuously, it will have a very high initial startup current.
>>
>>
>>
>> By using #6 wire the voltage drop should be minimal.
>
> It's also minimal with #8 and the percent voltage drop difference
> between #6 and #8 is insignificant. Which is why you can wire even a
> 5 ton AC with number #8.
>

I am sure you can but if the mfg says #6 I'd just go with what they say.

[philo]

Per Ohm's Law, to increase the current you will need to raise the voltage.

[Stormin Mormon]

Well, figuring a static load. What did you say?
I can't hear you with all that static.

[milli...@yahoo.com]

Hi, I'm the OP.

The unit is a Sea Breeze SMZ42H46ZOGX.
The instruction manual and even the promo literature explicitly calls out a 6AWG Stranded 3 Conductor cable, with a 50amp breaker.

Weird thing is that of the 3 conductors, it appears to send one to ground (http://i899.photobucket.com/albums/ac194/millinghill/Capture_zps3e1fd5ca.jpg). And since I have a "6-3 Romex NM-B with ground", I now seem to have an extra (unused) wire... the neutral.

Do you agree?

[milli...@yahoo.com]

Sounds like you're suggesting they overcompensated, but I will not be so bold as to disregard a specification that explicitly says use 6AWG with a 50Amp breaker.
From the literature:

Rated Voltage & Frequency and Phase :208-230 / 1PH
Min./ Max. Operating Voltage :187 / 253 VAC
Circuit Breaker Size (A): 50
Min. Circuit Ampacity (A): 26
Wiring (Outdoor unit to Power Disconnect): 3C- 6 AWG (minimum)

[milli...@yahoo.com]

It's strictly a heat pump/AC.
No resistance heat that I can see on the specs.

[mako...@yahoo.com]

Ok here is the logic
The manufacturer probably specified a 50 amp breaker to reduce trips during the startup inrush. You all know an a/c has a large inrush current.
Now if you are using a 50 amp breaker you MUST use #6ga or larger wire to be safe and meet code.
The breaker and wire size must match to be safe.
But it does seem the directions were confusing re the number of conductors needed.
6-2 is three total conductors, 2 that carry current and one safety ground.

Mark

[trader_4]

On Friday, August 1, 2014 7:54:14 AM UTC-4, mako...@yahoo.com wrote:
> Ok here is the logic
>
> The manufacturer probably specified a 50 amp breaker to reduce trips during the startup inrush. You all know an a/c has a large inrush current.
>
> Now if you are using a 50 amp breaker you MUST use #6ga or larger wire to be safe and meet code.

I'm surprised it took this long for someone to post this, which is
wrong. Breakers for equipment with motor loads are not sized like
a circuit for receptacles or a heater. It's perfectly permissible to
have a 50A breaker on an #8 gauge wire for an AC. The overcurrent
protection is in the eqpt and it's rated for that installation.

I agree with Gfre, whoever wrote that manual, wherever they are located,
(China?), doesn't know what they are doing. Proof that they don't is
clearly demonstrated by them calling for 3 conductor cable, while they
really mean 2 conductor plus ground. Another very curious thing that
I've never seen before, look at what goes from the outside unit to power
the evaporator unit(s) that shown in the posted link. And in the spec
they call that 4 conductor. What they are showing looks like 3 conductors
plus ground, all used. So, what they are clearly showing is a
240V only connection coming in to the outside unit, then a 240V connection
*with neutral* leaving it to power the evaporator(s). That seems *very*
strange to me.... It seems like they have established their own neutral,
unconneced to the service neutral, going to the other units.
Any thoughts Gfre?

Regarding the conductor sizing, I agree with Gfre. The spec sheet says
26A min circuit ampacity. The rated power input is 4600W max. Based on that,
10g would be sufficient. Does this thing have backup resistance electric
heat by any chance? I doubt it because it's not in the spec sheet. If
it were my install, I'd go by the rating plate. At 26A, I'd just bump it
up to 8g, 2 conductors. If anything, I'd say the big honking cable with
an extra unused conductor is more likely to draw an inspectors attention,
because it looks odd and likely a DIY.


In most places this should have a permit. Why not write down what's on the
eqpt tag and take that, the manual, and the spec sheet and go ask the
inspector?

>
> The breaker and wire size must match to be safe.

Wrong.

>
> But it does seem the directions were confusing re the number of conductors needed.
>
> 6-2 is three total conductors, 2 that carry current and one safety ground.
>
>
>
> Mark

And wrong again. 6-2 is TWO conductors, plus a ground. The ground is
*not* a conductor.

[milli...@yahoo.com]

trader4 says: " It seems like they have established their own neutral,

unconneced to the service neutral, going to the other units. "

My assumption is that this is not a self-establised neutral, but the wiring control (from the indoor evaporator) that tells the outdoor condenser to switch from A/C to heat pump.

Side note: kind of strange to me that the indoor units are 220VAC. Call me paranoid, but I wouldn't have minded a true neutral and only 120VAC to each indoor unit.

[trader_4]

On Friday, August 1, 2014 9:44:01 AM UTC-4, milli...@yahoo.com wrote:
> trader4 says: " It seems like they have established their own neutral,
>
> unconneced to the service neutral, going to the other units. "
>
>
>
> My assumption is that this is not a self-establised neutral, but the wiring control (from the indoor evaporator) that tells the outdoor condenser to switch from A/C to heat pump.
>
>

I was thinking of it strictly in terms of power and the fact that in
the diagram, that wire is marked N(1). Marking it N and having it wired
right there with the two hots, sure strongly suggests it's a neutral.
Do they talk about what that N(1) means at all?

But if those wires are the only link between the outside and inside eqpt,
then I agree signalling would have to go on it. It's even possible it
serves both functions, but if it's like you're suggesting, it makes sense
electrically. But if it's signalling, I wonder what code says about
that? ie, combining signalling, which would normally be low voltage with
240V? I guess it they use 240V to do the signalling, then it's OK, but
they couldn't AFAIK use 24V or similar.

Regarding using 240V to run the evaporators inside the house, I'd have
no problem with that. In Europe, many places, 220 is standard receptacle
voltage. Also, something many folks miss, it's pretty hard to wind up
with 240V going through you. You'd have to make contact with *both* hot
legs. Far more likely is standing in water, touching ground and one hot,
in which case, it's still 120V.

[trader_4]

On Friday, August 1, 2014 10:46:28 AM UTC-4, gfre...@aol.com wrote:

> On Fri, 1 Aug 2014 06:42:25 -0700 (PDT), milli...@yahoo.com wrote:
>
>
>
> >trader4 says: " It seems like they have established their own neutral,
>
> >unconneced to the service neutral, going to the other units. "
>
> >
>
> >My assumption is that this is not a self-establised neutral, but the wiring control (from the indoor evaporator) that tells the outdoor condenser to switch from A/C to heat pump.
>
> >
>

> >Side note: kind of strange to me that the indoor units are 220VAC. Call me paranoid, but
>
>
>

> The mini splits are usually "inverter" designs so they do generate
>
> their own voltages in the unit. I bet the voltages going to each
>
> inside unit are not line voltage at all. The ones I have use a low
>
> voltage (24 or so)

Interesting. I just assumed line voltage in, line voltage out,
which I guess it isn't. As you point out, all they really need is
power for the fan and a communications link of some kind, so how
they do it is up to them.

[cl...@snyder.on.ca]

On Fri, 01 Aug 2014 00:32:34 -0400, gfre...@aol.com wrote:

>On Thu, 31 Jul 2014 20:25:57 -0700 (PDT), milli...@yahoo.com wrote:
>
>>SMZ42H46ZOGX
>
>When I look this up I do see where the manual says you need 6 ga wire
>but it also says "Minimum circuit ampacity 26a" which would be 10
>gauge copper according to the NEC. It really sounds like the chinese
>book writer does not understand the electrical code.
>
>Does the label on the outside unit say "26a" on the minimum circuit
>ampacity line?
>Maximum over current protection probably says "50a"
26 amps is more than 80% of 30 amps. Generally a circuit should not
excede 80% of the circuit protection rating (fuse or breaker - and I
assume wiring). Also, if I remember and read correctly, the
specification is for a "stranded" wire - which "generally" should be
sized up 1 size. So up one from 10 because it is over 80% circuit
capacity, and up one for stranded would be a #6 stranded cordWhich
would explain the recommendadation - and would allow a #8 solid
conductor.
Still. not hurting anything but the pocketbook using #6, and using
3+ground instead of 2+ground is costing a lot more than the guage
upgrade. Remember - it was talking about a "3 conductor stranded cord"
- which is black/white/green. Using solid cable that is 2+ground -
black, white, and bare.

[cl...@snyder.on.ca]

Unless flexible cord is used - it said 3 conductor - which COULD be
read either way. And many air conditioner installations do spec
flexible cable between the house (disconnect) and the unit.
And remember - if the unit draws a constant 26 amps, it is over-spec
for a 30 amp circuit (maximum 80% rated current for continuous use)

[trader_4]

On Friday, August 1, 2014 11:41:20 PM UTC-4, cl...@snyder.on.ca wrote:
> On Fri, 1 Aug 2014 04:54:14 -0700 (PDT), mako...@yahoo.com wrote:
>
>
>
> >Ok here is the logic
>
> >The manufacturer probably specified a 50 amp breaker to reduce trips during the startup inrush. You all know an a/c has a large inrush current.
>
> >Now if you are using a 50 amp breaker you MUST use #6ga or larger wire to be safe and meet code.
>
> >The breaker and wire size must match to be safe.
>
> >But it does seem the directions were confusing re the number of conductors needed.
>
> >6-2 is three total conductors, 2 that carry current and one safety ground.
>
> >
>
> >Mark
>
> Unless flexible cord is used - it said 3 conductor - which COULD be
>
> read either way.

No it can't. The ground is not referred to as a conductor, by code,
by the manufacturer, or by anyone who knows what they are doing. Go
look at a box of Romex. It's sold as 14/2, 14/3, with ground. That is
either two or three conductors plus ground.

And many air conditioner installations do spec
>
> flexible cable between the house (disconnect) and the unit.

Please show us some examples, I've never seen one.

>
> And remember - if the unit draws a constant 26 amps, it is over-spec
>
> for a 30 amp circuit (maximum 80% rated current for continuous use)

Wrong again. The eqpt is marked for a circuit with a minimum ampacity
of 26A. A 30 Amp circuit exceeds that.

[trader_4]

On Saturday, August 2, 2014 12:40:28 AM UTC-4, gfre...@aol.com wrote:

> On Fri, 01 Aug 2014 23:34:13 -0400, cl...@snyder.on.ca wrote:
>
>
>
> >On Fri, 01 Aug 2014 00:32:34 -0400, gfre...@aol.com wrote:
>
> >
>
> >>On Thu, 31 Jul 2014 20:25:57 -0700 (PDT), milli...@yahoo.com wrote:
>
> >>
>
> >>>SMZ42H46ZOGX
>
> >>
>
> >>When I look this up I do see where the manual says you need 6 ga wire
>
> >>but it also says "Minimum circuit ampacity 26a" which would be 10
>
> >>gauge copper according to the NEC. It really sounds like the chinese
>
> >>book writer does not understand the electrical code.
>
> >>
>
> >>Does the label on the outside unit say "26a" on the minimum circuit
>
> >>ampacity line?
>
> >>Maximum over current protection probably says "50a"
>
> > 26 amps is more than 80% of 30 amps. Generally a circuit should not
>
> >excede 80% of the circuit protection rating (fuse or breaker - and I
>
> >assume wiring).
>
>
>

> That is not what the label says or what it means.
>
> If you look at the U/L marking guide, you will see the 80% is built
>
> into that "minimum circuit ampacity"

+1

This is a specific piece of eqpt on a dedicated circuit. It's not
a circuit for receptacles. The rules are different. Just like a
previous poster thinks you can't have a 50A breaker on 8g wiring for
an AC, when you can, because the rules are different.


>
> I bet the design FLA is more like 19-20a and the actual max you would
>
> ever read with an amp probe is more like 15-16 in normal operation
>
> They say strange numbers like "26a" to keep you out of 12ga which is
>
> rated for 25a in the 60 and 75c column.
>
> The marking guide and the label itself is clearly saying 10 ga copper.

>
>
>
> >Also, if I remember and read correctly, the
>
> >specification is for a "stranded" wire - which "generally" should be
>
> >sized up 1 size.
>
>
>

> Cite that.
>
> Table 310-16 does not make that distinction

Yes, I'd like to see that too. AFAIK, solid and stranded of
the same gauge have the same current carrying capacity, unless
this AC is connected to a 1Mhz power source, or similar where
skin effect comes into play.

[Doug Miller]

cl...@snyder.on.ca wrote in news:gjmot9tuachl9v4dl...@4ax.com:

> 26 amps is more than 80% of 30 amps. Generally a circuit should not
> excede 80% of the circuit protection rating (fuse or breaker - and I
> assume wiring).

Wrong. The 80% rule applies only to continuous loads.

You really should stop trying to give electrical advice.

[Doug Miller]

cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1...@4ax.com:

> And remember - if the unit draws a constant 26 amps, it is over-spec
> for a 30 amp circuit (maximum 80% rated current for continuous use)

The term "continuous" has a clear, specific definition in the Code -- and an air conditioner
does not meet that definition.

[cl...@snyder.on.ca]

On Sat, 02 Aug 2014 00:40:28 -0400, gfre...@aol.com wrote:

>On Fri, 01 Aug 2014 23:34:13 -0400, cl...@snyder.on.ca wrote:
>

>>On Fri, 01 Aug 2014 00:32:34 -0400, gfre...@aol.com wrote:
>>
>>>On Thu, 31 Jul 2014 20:25:57 -0700 (PDT), milli...@yahoo.com wrote:
>>>
>>>>SMZ42H46ZOGX
>>>
>>>When I look this up I do see where the manual says you need 6 ga wire
>>>but it also says "Minimum circuit ampacity 26a" which would be 10
>>>gauge copper according to the NEC. It really sounds like the chinese
>>>book writer does not understand the electrical code.
>>>
>>>Does the label on the outside unit say "26a" on the minimum circuit
>>>ampacity line?
>>>Maximum over current protection probably says "50a"
>> 26 amps is more than 80% of 30 amps. Generally a circuit should not
>>excede 80% of the circuit protection rating (fuse or breaker - and I
>>assume wiring).
>

>That is not what the label says or what it means.
>If you look at the U/L marking guide, you will see the 80% is built
>into that "minimum circuit ampacity"

>I bet the design FLA is more like 19-20a and the actual max you would
>ever read with an amp probe is more like 15-16 in normal operation
>They say strange numbers like "26a" to keep you out of 12ga which is
>rated for 25a in the 60 and 75c column.
>The marking guide and the label itself is clearly saying 10 ga copper.
>

>>Also, if I remember and read correctly, the
>>specification is for a "stranded" wire - which "generally" should be
>>sized up 1 size.
>

>Cite that.
>Table 310-16 does not make that distinction

Where did I say code required it? I said it "generally should" - and
I'll stick to that. I like to see stranded power cords for high
amperage applications - like Generators and table saws- upsized one
size over what I would use with solid copper.

[cl...@snyder.on.ca]

OK - what does "continuous" mean? What minimum duty cycle is
required for it to be "continuous"? How long does the air conditioner
run on the hottest day of the year? Is the running current not
"continuous" in this case? Starting amps don't count. Do you KNOW what
the steady state running current of the AC unit in question is??

My assumption is the AC unit would draw 26 amps for more than 20 min
utes at a time, up to full time operation, it is to be connected with
a 3 conductor (including ground) flexible stranded cable.

Your assumptions are no more valid than mine, whatever they are -
unless you KNOW what current the unit draws and KNOW it will never
approach 100% duty cycle

[cl...@snyder.on.ca]

On Sat, 02 Aug 2014 10:36:24 -0400, gfre...@aol.com wrote:

>Yup, you set a guy's hair on fire if his knowledge stops at the Time
>Life "electric for dummies" book. There are places where you can have
>12 gauge wire on a 50 and 14 on a 40. It is a common question on the
>inspector tests.
>(typical was, 1HP 120v, 16 FLA motor on a 40a breaker with 14ga
>copper)

>
>>
>>>
>>> I bet the design FLA is more like 19-20a and the actual max you would
>>>
>>> ever read with an amp probe is more like 15-16 in normal operation
>>>
>>> They say strange numbers like "26a" to keep you out of 12ga which is
>>>
>>> rated for 25a in the 60 and 75c column.
>>>
>>> The marking guide and the label itself is clearly saying 10 ga copper.
>>>
>>>
>>>
>>> >Also, if I remember and read correctly, the
>>>
>>> >specification is for a "stranded" wire - which "generally" should be
>>>
>>> >sized up 1 size.
>>>
>>>
>>>
>>> Cite that.
>>>
>>> Table 310-16 does not make that distinction
>>
>>Yes, I'd like to see that too. AFAIK, solid and stranded of
>>the same gauge have the same current carrying capacity, unless
>>this AC is connected to a 1Mhz power source, or similar where
>>skin effect comes into play.
>

>Yup, the stranded is actually better if you start getting up in the
>higher frequencies. You can see the effect at 400hz which used to be
>pretty common in computer rooms. (back when they actually had real
>computers in there) ;-)
>The big 400hz cables were usually fine stranded.
>
>If you look at table 8 you will see that the DC resistance of stranded
>#10 is actually 0.03 ohms more than solid per 1000 feet but that is
>insignificant for this calculation and the difference is a little less
>at 60hz

Skin effect doesn't even begin to have any effect in residential or
normal commercial wiring. I know code does not require upsizing for
stranded wire - I never said it did. I said, generally one should use
one size heavier flexible cord than one would use for solid permanent
wiring. I stand by that. Flexible cable is submitted to a lot of
flexing which will eventually compromize some strands, increasing the
resistance. It is a good idea to use one size heavier cable than
"required", particularly when running close to the design current
limit for the cord.
In general practice, MOST people use a cord that is AT LEAST one size
too SMALL for the load.

[cl...@snyder.on.ca]

On Sat, 02 Aug 2014 11:02:16 -0400, gfre...@aol.com wrote:

>On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
><doug_at_mil...@example.com> wrote:
>

>Air conditioners are such a specific load that it really requires an
>engineer to specify the circuit ampacity and over current protection.
>That is why the U/L marking guide specifies this on the label.
>
>Motor loads are subject to the 80% rule but that is 125% of the
>nameplate FLA and you use table 310.16 to determine wire size, not
>240.4(D)
And if the manufacturer(on the UL label) specifies #6 wire be used
for connection, it does NOT meet code if installed with #8 or #10

[trader_4]

On Saturday, August 2, 2014 3:51:59 PM UTC-4, cl...@snyder.on.ca wrote:
> On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
>
> <doug_at_mil...@example.com> wrote:
>
>
>
> >cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1...@4ax.com:
>
> >
>
> >> And remember - if the unit draws a constant 26 amps, it is over-spec
>
> >> for a 30 amp circuit (maximum 80% rated current for continuous use)
>
> >
>
> >The term "continuous" has a clear, specific definition in the Code -- and an air conditioner
>
> >does not meet that definition.
>
> >
>
> >You really should stop trying to give electrical advice.
>
> OK - what does "continuous" mean?

It would seem if you're giving out the advice, you should know that
no? And if not, googling "code definition continous load" should work.

What minimum duty cycle is
>
> required for it to be "continuous"? How long does the air conditioner
>
> run on the hottest day of the year? Is the running current not
>
> "continuous" in this case? Starting amps don't count. Do you KNOW what
>
> the steady state running current of the AC unit in question is??
>
>
>
> My assumption is the AC unit would draw 26 amps for more than 20 min
>
> utes at a time, up to full time operation, it is to be connected with
>
> a 3 conductor (including ground) flexible stranded cable.
>
>
>
> Your assumptions are no more valid than mine, whatever they are -
>
> unless you KNOW what current the unit draws and KNOW it will never
>
> approach 100% duty cycle

That doesn't matter, because per Gfre, all that has been taken into
account by the engineers who designed and rated the eqpt. The eqpt rating plate is what governs, it says a circuit with minimum ampacity of 26A,
which you then use to directly determine the wire size.

[trader_4]

Except of course that the manufacturer did not say #6 or any gauge on the
UL label. Nor have I ever seen gauge on a similar label. The governing data
on the eqpt label is the 26A, if he chooses to follow that. The manufacturer
stated #6 gauge in the install manual, which was obviously written by a buffoon, because they don't understand the difference between conductors and
grounds. The install instructions say that it's to be installed with
4 conductors and then they show only a 240V connection, no neutral, just like
you'd expect with any other air conditioner. So, following that, even
after correcting it to 3 conductors, plus ground, you'd have an extra
wire that goes nowhere. Would you follow that too?

That 3.7 ton AC would have to be the most inefficient piece of crap ever
made to need #6. It would be so inefficient, it couldn't meet the min
SEER required today. It also states in the spec that the rated input power
is 4600 watts. 4600 watts = 19 amps. There is nothing there that comes
close to needing 6 gauge wire.

[trader_4]

You have your outside AC units swinging around in the breeze up
there in Canada? Around here, they *are* installed with permanent
wiring, not cords. And the cord reference is in the same lame
drawing, that was obviously written by a buffoon. They confuse
conductors with grounds and call for a 4 conductor cable. As I
already said, even if you allow that they really mean 3 conductors,
plus ground, it's still wrong. The drawing only shows two hots, ie
a normal 240V AC connection. So, following that, we should get a
big old honking 6 gauge 4 conductor stranded "cord". Then leave two
conductors unused. Then let;s call the inspector over and see how he
likes it.

Or we could use two #8 THWN stranded run inside liquidtight. Actually
per the eqpt label, you could use #10, but since the 26A is close to
the max for #10, I'd bump it up.

It is a good idea to use one size heavier cable than
>
> "required", particularly when running close to the design current
>
> limit for the cord.

Cable? Cord? Which is it now? Better rip out all your 14 gauge that's
on 15 amp breakers, make it 12 gauge.

>
> In general practice, MOST people use a cord that is AT LEAST one size
>
> too SMALL for the load.

In general practice around here, people don't install permanent,
outdoor AC eqpt with cords. And I've never seen a 3.7 ton AC unit
on #6 anything, cord, stranded, solid, etc.

[trader_4]

You see outside permanently mounted AC condenser/compressor units on
power cords much up there?

[cl...@snyder.on.ca]

On Sat, 02 Aug 2014 15:59:53 -0400, gfre...@aol.com wrote:

>On Sat, 02 Aug 2014 15:51:59 -0400, cl...@snyder.on.ca wrote:
>
>>On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
>><doug_at_mil...@example.com> wrote:
>>
>>>cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1...@4ax.com:
>>>
>>>> And remember - if the unit draws a constant 26 amps, it is over-spec
>>>> for a 30 amp circuit (maximum 80% rated current for continuous use)
>>>
>>>The term "continuous" has a clear, specific definition in the Code -- and an air conditioner
>>>does not meet that definition.
>>>
>>>You really should stop trying to give electrical advice.
>> OK - what does "continuous" mean? What minimum duty cycle is
>>required for it to be "continuous"? How long does the air conditioner
>>run on the hottest day of the year? Is the running current not
>>"continuous" in this case? Starting amps don't count. Do you KNOW what
>>the steady state running current of the AC unit in question is??
>>

>Continuous is 3 hours in the NEC.

>
>
>>My assumption is the AC unit would draw 26 amps for more than 20 min
>>utes at a time, up to full time operation, it is to be connected with
>>a 3 conductor (including ground) flexible stranded cable.
>>
>>Your assumptions are no more valid than mine, whatever they are -
>>unless you KNOW what current the unit draws and KNOW it will never
>>approach 100% duty cycle
>

>It is really not even a factor here. The "minimum circuit ampacity" is
>an engineered value based on that particular piece of equipment and
>takes into account all applicable factors.
>In this case a 10 gauge copper wire will fulfill that requirement.
So why does the instruction specify a #6??????
If the manufacturer's UL listing spec requires a #6, it doesn't meet
code to connect with a #10.

[trader_4]

We don't have access to the UL listing spec. All we have are the eqpt
rating plate and one page of the install manual. That one page, was
obviously written by a complete buffoon. They call for #6 and in the
diagram call it a cord. How many outside AC condenser/compressor units
have you seen installed on cords?

And then they call for 4 conductor cord. Lets take that literally too.
So, we have 4 conductors and a ground? WTF? OK, whooops, I guess
they really meant 3 conductors plus ground. So we get a big honking
#6 cord, with 3 conductors plus ground. Whooops! They only show two conductors actually used, ie like you'd expect for a 240V AC unit. So
I guess the extra one is for good luck, but heh, they said to do it
righ? In other words, whoever wrote that manual, proably in China,
didn't know WTF they were talking about.

On the other hand, we do know the unit is rated at 3.7 tons. That
the rated input power is 4600 watts and that the eqpt label says the
min circuit ampacity is 26A. All that says #6 is nuts and that 10g
would suffice. Since 26A is close, I'd go with #8. And I would not
use a cord, which I don't think would even pass code here. I'd put
THWN, #8, 2 conductors plus ground, inside liquidtight. The OP as
always, can do as he chooses.

[Doug Miller]

gfre...@aol.com wrote in news:5jgqt9hd2nbqfletv...@4ax.com:

> On Sat, 02 Aug 2014 15:51:59 -0400, cl...@snyder.on.ca wrote:
>

>>On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
>><doug_at_mil...@example.com> wrote:
>>
>>>cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1...@4ax.com:
>>>
>>>> And remember - if the unit draws a constant 26 amps, it is over-spec
>>>> for a 30 amp circuit (maximum 80% rated current for continuous use)
>>>
>>>The term "continuous" has a clear, specific definition in the Code -- and an air
conditioner
>>>does not meet that definition.
>>>
>>>You really should stop trying to give electrical advice.
>> OK - what does "continuous" mean? What minimum duty cycle is
>>required for it to be "continuous"? How long does the air conditioner
>>run on the hottest day of the year? Is the running current not
>>"continuous" in this case? Starting amps don't count. Do you KNOW what
>>the steady state running current of the AC unit in question is??
>>

> Continuous is 3 hours in the NEC.

At maximum current.

[Doug Miller]

cl...@snyder.on.ca wrote in news:h0gqt9p6q0i7sn2hi...@4ax.com:

> On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
> <doug_at_mil...@example.com> wrote:
>
>>cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1...@4ax.com:
>>
>>> And remember - if the unit draws a constant 26 amps, it is over-spec
>>> for a 30 amp circuit (maximum 80% rated current for continuous use)
>>
>>The term "continuous" has a clear, specific definition in the Code -- and an air conditioner
>>does not meet that definition.
>>
>>You really should stop trying to give electrical advice.
> OK - what does "continuous" mean?

"Continuous load: a load where the maximum current is expected to continue for three hours
or more." [NEC, Article 100]

>What minimum duty cycle is
> required for it to be "continuous"?

See above.

>How long does the air conditioner
> run on the hottest day of the year?

Immaterial. The only relevant question is, does it pull maximum current for three hours or
more?

> Is the running current not
> "continuous" in this case?

It does not appear to meet the NEC's definition of a continuous load -- a definition you're
clearly ignorant of.

>Starting amps don't count. Do you KNOW what
> the steady state running current of the AC unit in question is??

From the data posted by the OP, apparently it's 26 amps.

>
> My assumption is the AC unit would draw 26 amps for more than 20 min
> utes at a time, up to full time operation, it is to be connected with
> a 3 conductor (including ground) flexible stranded cable.
>
> Your assumptions are no more valid than mine, whatever they are -
> unless you KNOW what current the unit draws and KNOW it will never
> approach 100% duty cycle

Wrong yet again. I never said it would not approach 100% duty cycle, and that's not what's
meant by "continuous load".

[Doug Miller]

trader_4 <tra...@optonline.net> wrote in news:721afe4d-95af-4321-a785-f2428f838f82
@googlegroups.com:

> On Saturday, August 2, 2014 3:51:59 PM UTC-4, cl...@snyder.on.ca wrote:
>> On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
>> <doug_at_mil...@example.com> wrote:
>> >cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1...@4ax.com:
>> >> And remember - if the unit draws a constant 26 amps, it is over-spec
>> >> for a 30 amp circuit (maximum 80% rated current for continuous use)
>>
>> >The term "continuous" has a clear, specific definition in the Code -- and an air
conditioner
>> >does not meet that definition.
>>
>> >You really should stop trying to give electrical advice.
>>
>> OK - what does "continuous" mean?
>
> It would seem if you're giving out the advice, you should know that
> no? And if not, googling "code definition continous load" should work.

Not knowing what the Code says hasn't ever previously prevented him from giving
electrical advice; no reason to expect that to change now, is there?

[Doug Miller]

cl...@snyder.on.ca wrote in news:4pgqt9dvss4bo4065...@4ax.com:

[...]

> And if the manufacturer(on the UL label) specifies #6 wire be used
> for connection, it does NOT meet code if installed with #8 or #10

Just stop. You're only digging the hole deeper.

UL labels specify voltage, amperage, wattage -- but when have you seen one that specifies
the size of the circuit conductors?

[trader_4]

Agree with you except for the above. The "min circuit ampacity" is 26.
The rated load amps is 19. It also says the rated input power is 4600W.
Clearly it's running closer to 19 amps, not 26. The exact current is
going to vary based on the exact conditions present at the time. But all
that is taken into account when they spec'd the min circuit amps at 26.
The unit is only 41K btu, ie 3.7 tons. It's impossible for a unit to
need #6, if it drew that much power and only produced 3.7 tons, it would
never meet the min govt SEER standards.

It's obvious whoever wrote that manual made several mistakes. If it were
me, I'd use #8 and a 50A breaker, which is consistent with the unit label
and be done with it. I suggested previously that if this needs to be
permitted, the OP could take the relevant info to the inspector and ask.
I for sure would do one of the above before I installed it with #6, using a
*4 conductor *cord*, because the lame manual says so.

[cl...@snyder.on.ca]

On Sat, 2 Aug 2014 22:25:10 +0000 (UTC), Doug Miller

<doug_at_mil...@example.com> wrote:

>gfre...@aol.com wrote in news:5jgqt9hd2nbqfletv...@4ax.com:
>
>> On Sat, 02 Aug 2014 15:51:59 -0400, cl...@snyder.on.ca wrote:
>>
>>>On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
>>><doug_at_mil...@example.com> wrote:
>>>
>>>>cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1...@4ax.com:
>>>>
>>>>> And remember - if the unit draws a constant 26 amps, it is over-spec
>>>>> for a 30 amp circuit (maximum 80% rated current for continuous use)
>>>>
>>>>The term "continuous" has a clear, specific definition in the Code -- and an air
>conditioner
>>>>does not meet that definition.
>>>>
>>>>You really should stop trying to give electrical advice.
>>> OK - what does "continuous" mean? What minimum duty cycle is
>>>required for it to be "continuous"? How long does the air conditioner
>>>run on the hottest day of the year? Is the running current not
>>>"continuous" in this case? Starting amps don't count. Do you KNOW what
>>>the steady state running current of the AC unit in question is??
>>>
>> Continuous is 3 hours in the NEC.
>
>At maximum current.

And how much current does this AC unit draw, steady state? And how
long will it run on the hottest day of the year, in the hottest year
in 10 years???

[cl...@snyder.on.ca]

On Sat, 2 Aug 2014 22:28:45 +0000 (UTC), Doug Miller

If the AC unit runs at 26 FLA for 3 hours and 1 minute on the hottest
day of the year, it is over 80% and "continuous" by code, so the wire
needs to be derated to 80%., meaning it needs a larger cable.

[cl...@snyder.on.ca]

On Sat, 2 Aug 2014 22:31:25 +0000 (UTC), Doug Miller

<doug_at_mil...@example.com> wrote:

>trader_4 <tra...@optonline.net> wrote in news:721afe4d-95af-4321-a785-f2428f838f82
>@googlegroups.com:
>
>> On Saturday, August 2, 2014 3:51:59 PM UTC-4, cl...@snyder.on.ca wrote:
>>> On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
>>> <doug_at_mil...@example.com> wrote:
>>> >cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1...@4ax.com:
>>> >> And remember - if the unit draws a constant 26 amps, it is over-spec
>>> >> for a 30 amp circuit (maximum 80% rated current for continuous use)
>>>
>>> >The term "continuous" has a clear, specific definition in the Code -- and an air
>conditioner
>>> >does not meet that definition.
>>>
>>> >You really should stop trying to give electrical advice.
>>>
>>> OK - what does "continuous" mean?
>>
>> It would seem if you're giving out the advice, you should know that
>> no? And if not, googling "code definition continous load" should work.
>
>Not knowing what the Code says hasn't ever previously prevented him from giving
>electrical advice; no reason to expect that to change now, is there?

If the AC runs for 3 hours and 1 minute without shutting down at 26
amps, a #10 cable is undersized for the application.
That is according to your interpretation of the code.
Is it inconceiveable that this air conditioner could run for over 3
hours at a time???

If this AC can run for more than 3 hours without shutting down,and it
draws 26 amps, it requires #8 cable. If the rating label states it
requires a #6 cable, it requires a #6 cable to meet code.
I don't pretend to know WHY the manufacturer specified a #6 cable,
when according to code a #8 would be adequate. My only GUESS is it had
something to do with the specification that the unit was to be
connected with stranded cable (I believe that was part of the original
post) - in which case the premises wiring could be #8 and the flex
cable be #6.. The specification was 3 conductor # 6 flexible cable,
and the OP misread that to be NMD or NMW6-3 + ground from the service
panel to the unit.

That's MY take on it.

[cl...@snyder.on.ca]

I thought the OP said the label on the unit gave the circuit
requirements and the cable specification. I could have misread that.
My reader does not make it easy to go back to previous posts in a
thread, so I'm going by memory.

[trader_4]

You're confused again. The 26 amps is not FLA, it's the spec for the
minimum ampacity of the circuit. The rest is the wire size that will
support 26A. You're taking what was already calculated by engineers
and applying factors on top of the factors they already applied when
they did the UL listing.

[cl...@snyder.on.ca]

I just went bact to the OP's post. I quote:
"Hi, I'm the OP.
Yes, the mini split a/c system specs explicitly call for a 50amp
breaker and #6 AWG (although I shudder to think that it'll actually
use that much, with a 16 SEER)."

What does the code say about over-protecting a cable?
The cable is protected by a 50 amp breaker. Going by "general code"
you cannot run an AWG10 circuit on a 50 amp circuit.
What specifics outside of the "general code" would allow the cable to
be protected with an over-rated protection device?
And yes, the air conditioner in my house is connected with stranded
flexible conductors from the house to the outside unit - run through
weatherproof flexible conduit to the "protected disconnect" - a
weatherproof single circuit circuit breaker enclosure.
The outdoor unit sits on a plarform of concrete blocks on a base of
concrete patio stones, and is not bolted down.. Been that way for over
40 years. (except the original unit sat right on the patio stones, I
raised the unit on concrete blocks to keep it out of the dirt and
leaves when I had the unit replaced.

[trader_4]

OMG, here we go again. Gfre went through that days ago. I did
too when yesterday someone started in with the same nonsense.
The 15 amps for 14g, 20 amps for 12g, 30 amps for 10g rules
works for lights and receptacles.
It doesn't work for motor and compressor loads. You can indeed have
a 50 amp breaker on 10g wire because the overcurrent protection in
the AC load is in the AC. The breaker is there to protect against
short circuits and it needs to be 50A to handle the brief startup
current.

>
> What specifics outside of the "general code" would allow the cable to
>
> be protected with an over-rated protection device?

The rest of the code that covers motors, HVAC compressors, etc.?

>
> And yes, the air conditioner in my house is connected with stranded
>
> flexible conductors from the house to the outside unit - run through
>
> weatherproof flexible conduit to the "protected disconnect" - a
>
> weatherproof single circuit circuit breaker enclosure.

And you call that a *cord* up in Canada? Around here we call that
THWN run in liquidtight.

>
> The outdoor unit sits on a plarform of concrete blocks on a base of
>
> concrete patio stones, and is not bolted down.. Been that way for over
>
> 40 years. (except the original unit sat right on the patio stones, I
>
> raised the unit on concrete blocks to keep it out of the dirt and
>
> leaves when I had the unit replaced.

You see any up there that use #6?, especially a minisplit that's just
3.7 toms? If it needed that much power it would be such a pig that
it could not be sold because it wouldn't meet the min SEER standards.
That's the nutty part about this. Just from practical experience it's
obvious that #6 is a mistake.

And back to the original issue, here's another way of looking at it.
You're looking in the wrong end of the telescope. You're trying to
analyze the load, apply rules and then size the circuit. The engineers
already did that. They put "min circuit ampacity 26A on the UL label.
That means the load is saying, "Hook me up to a circuit capable of
supplying 26A or more."

[trader_4]

On Saturday, August 2, 2014 7:41:32 PM UTC-4, gfre...@aol.com wrote:

> On Sat, 02 Aug 2014 19:20:14 -0400, cl...@snyder.on.ca wrote:
>
>
>
>
>
> > And how much current does this AC unit draw, steady state? And how
>
> >long will it run on the hottest day of the year, in the hottest year
>
> >in 10 years???
>
>
>

> If it draws much over 15amps the seer would be so low you could not
>
> even install it in any state with an energy code.

+1

I made exactly the same point. The spec sheet says the rated imput wattage is
4600W. That's 19A, which also happens to be the compressor RLA. It's 41000btu,
3.7 tons. And it's 16 SEER. You couldn't sell it here period, it wouldn't
meet the min federal SEER standards. Just from practical experience, #6
makes no sense.

Clare is looking in the wrong end of the telescope. He's trying to analyze
the load. The engineers already did that and put the "min circuit ampacity 26A"
on the UL label. The load is saying, "Hook me up to a 26A or greater circuit."

[cl...@snyder.on.ca]

On Sat, 02 Aug 2014 19:41:32 -0400, gfre...@aol.com wrote:

>On Sat, 02 Aug 2014 19:20:14 -0400, cl...@snyder.on.ca wrote:
>
>

>> And how much current does this AC unit draw, steady state? And how
>>long will it run on the hottest day of the year, in the hottest year
>>in 10 years???
>

>If it draws much over 15amps the seer would be so low you could not
>even install it in any state with an energy code.

How many BTUs is the unit? If it is a high BTU unit, the seer could
still be pretty good with over 25 amps of current draw.

Regardless - the OP clearly stated the installation instructions
specified #6 cable and a 50 amp breaker. He also stated it requires a
"minimum ampacity" of 26 amps.

That is all we KNOW.

Do we have the manufacturer and model number of this "mythical
beast"???

[cl...@snyder.on.ca]

On Sat, 02 Aug 2014 19:44:01 -0400, gfre...@aol.com wrote:

>On Sat, 02 Aug 2014 19:23:06 -0400, cl...@snyder.on.ca wrote:
>
>
>>>
>>>Wrong yet again. I never said it would not approach 100% duty cycle, and that's not what's
>>>meant by "continuous load".
>> If the AC unit runs at 26 FLA for 3 hours and 1 minute on the hottest
>>day of the year, it is over 80% and "continuous" by code, so the wire
>>needs to be derated to 80%., meaning it needs a larger cable.
>

>Are you simply not paying attention here. The 80% does not apply here
>at all. It is already computed in the minimum circuit ampacity.
>Continuous load doesn't apply to motor loads anyway since the
>conductors are already sized to 125% of FLA.
>
And none of us knows enough about this "mythical beast" to know why it
is specified to be connected to a 50 amp breaker by AWG6 cable.

It's all conjecture at this point - your conjecture and mine equally
valid until more real information is provided.

[Doug Miller]

cl...@snyder.on.ca wrote in news:qnsqt9hc1ghk4la96...@4ax.com:

> On Sat, 2 Aug 2014 22:31:25 +0000 (UTC), Doug Miller
> <doug_at_mil...@example.com> wrote:
>
>>trader_4 <tra...@optonline.net> wrote in news:721afe4d-95af-4321-a785-f2428f838f82
>>@googlegroups.com:
>>
>>> On Saturday, August 2, 2014 3:51:59 PM UTC-4, cl...@snyder.on.ca wrote:
>>>> On Sat, 2 Aug 2014 14:05:32 +0000 (UTC), Doug Miller
>>>> <doug_at_mil...@example.com> wrote:

>>>> >cl...@snyder.on.ca wrote in news:e8not9po55dsmu3f1ap92udfqh327crtle@

4ax.com:
>>>> >> And remember - if the unit draws a constant 26 amps, it is over-spec
>>>> >> for a 30 amp circuit (maximum 80% rated current for continuous use)
>>>>
>>>> >The term "continuous" has a clear, specific definition in the Code -- and an air
>>conditioner
>>>> >does not meet that definition.
>>>>
>>>> >You really should stop trying to give electrical advice.
>>>>
>>>> OK - what does "continuous" mean?
>>>
>>> It would seem if you're giving out the advice, you should know that
>>> no? And if not, googling "code definition continous load" should work.
>>
>>Not knowing what the Code says hasn't ever previously prevented him from giving
>>electrical advice; no reason to expect that to change now, is there?
> If the AC runs for 3 hours and 1 minute without shutting down at 26
> amps, a #10 cable is undersized for the application.

Still wrong. Go back and read the definition I quoted. I was going to say, "read it *again*" but
it doesn't appear that you've read it once.

> That is according to your interpretation of the code.

"Interpretation"?? The language is pretty plain -- but you have to actually, you know, *read*
it first, before you know what it says.

> Is it inconceiveable that this air conditioner could run for over 3
> hours at a time???

It says, "... expected to continue for three hours or more".

[Doug Miller]

cl...@snyder.on.ca wrote in
news:qetqt9pgpc8gh9r68...@4ax.com:

Irrespective of what the OP may or may not have written, it's
pretty clear that you're not actually very familiar with what is,
or is not, on a UL label.

[cl...@snyder.on.ca]

On Sun, 3 Aug 2014 01:15:32 +0000 (UTC), Doug Miller

And on a very hot day I could expect my air conditioner to run for
more than 3 hours at a time.

[trader_4]

Maybe it's time to get a new reader? I don't know how anyone can competently
follow a thread without being able to go back to previous posts.

[trader_4]

On Saturday, August 2, 2014 8:42:04 PM UTC-4, cl...@snyder.on.ca wrote:
> On Sat, 02 Aug 2014 19:41:32 -0400, gfre...@aol.com wrote:
>
>
>
> >On Sat, 02 Aug 2014 19:20:14 -0400, cl...@snyder.on.ca wrote:
>
> >
>
> >
>
> >> And how much current does this AC unit draw, steady state? And how
>
> >>long will it run on the hottest day of the year, in the hottest year
>
> >>in 10 years???
>
> >
>
> >If it draws much over 15amps the seer would be so low you could not
>
> >even install it in any state with an energy code.
>
> How many BTUs is the unit? If it is a high BTU unit, the seer could
>
> still be pretty good with over 25 amps of current draw.
>
>

I think I'm starting to detect a big part of the problem here. You've now
said that with your newsreader you can't go back and view previous posts.
Now you're asking how many BTUS is the unit? I've posted that about 6 times
recently. You also haven't replied to any of my posts. So, it's obvious you've set your newsreader to ignore my replies or else you're deliberately
avoiding them and God knows what else. You're flying in the dark.

>
> Regardless - the OP clearly stated the installation instructions
>
> specified #6 cable and a 50 amp breaker. He also stated it requires a
>
> "minimum ampacity" of 26 amps.
>
>
>
> That is all we KNOW.
>
>
>
> Do we have the manufacturer and model number of this "mythical
>
> beast"???

Again, that was stated in previous posts. It's not all we know, because
at least Gfre and I have pulled up the actual spec sheet. For example, you've
asked "How much current does this draw?". The spec sheet clearly says the
RLA for the compressor is 19, the fan 1, the rated power input is 4600 Watts.
Again, I've posted that many times now, but you apparently don't give a damn
so you just ignore me and make an ass of yourself.

Sea Breeze SMZ42H46ZOGX.

[trader_4]

Plus it doesn't matter, because all of that was taken into account by
the engineers when they put "min circuit amapacity 26" on the UL label.
He's trying to analyze the load all over again, when it's been done and
the load is saying "hook me up to a 26A or better circuit".

[trader_4]

On Saturday, August 2, 2014 11:31:26 PM UTC-4, gfre...@aol.com wrote:

> On Sat, 02 Aug 2014 20:44:21 -0400, cl...@snyder.on.ca wrote:
>
>
>
> >And none of us knows enough about this "mythical beast" to know why it
>
> >is specified to be connected to a 50 amp breaker by AWG6 cable.
>
> >
>
> >It's all conjecture at this point - your conjecture and mine equally
>
> >valid until more real information is provided.
>
>
>

> He actually posted the model number and I had no problem finding the
>
> documentation. That is where I got the minimum ampacity. It is a tad
>
> less that 4 tons if he has the maximum number of evaporators
>
> connected. If there are fewer, it uses less power.

+1

This is unbelievable. He hasn't looked at either the spec sheet or the
pertinent data from it, which has all been posted here. In particular,
he's asking how many BTUs it is? I've posted about 6 times that it's
41000, or 3.7 tons. And that the RLA of the compressor is 19A, the fan is
1A, yet he's pretending it's normal running amps could be 26A for 3 hours?
Good grief!

And just from practical experience, has anyone ever seen a new 3.7 ton
AC connected with #6? As you pointed out, if it took that much power it
couldn't be sold because it wouldn't meet the min SEER standards.
That install manual has other big mistakes in
the wiring section, it calls for "4 conductor cord", when what they clearly
show connected is only the normal 2 conductors plus ground. Clare apparently
has even bought that and was arguing for connecting it with a "cord".

I think he's ignoring me. I guess it's better to remain in the dark.