airconditioner on an extension cord?
simon lai
a room in my house - the window mounted variety.
Specs say it draws 0.97kW, 4.1A @ 240V. The cord
that comes with the unit is 300mm long, insufficient
to reach the nearest powerpoint. My query to the
airconditioning installer as to whether an extension
cord could be used was met with shakes of the head
and disbelief - a "can't be done" sort of a response.
Most installers want to wire up another circuit which
adds ~$400 to the cost.
I was always under the impression that a reasonable
extension lead could handle 10 amps, and this one
would only need to be 2 metres long. The double
powerpoint, which would power the AC currently has
two PCs in it via a power board.
Is there something about the way air conditioners
draw their power that I don't understand or are the
installers just falling back on common practice?
In case it is relevant I am looking at the Panasonic
CW-C90YR - seems to have a reasonable star rating
(3.5/6).
simon
Ken Taylor
the contact resistance in the plug and socket when you connect the
extension lead. You *might* be able to get someone to re-wire the unit,
but it would void warranty and may not be legal (or safe). Although
extension cords and power points are rated for 10A, I hate to see them
supplying that. They burn after a relatively short while.
Ken
malcor
That 4.1 amps that the air conditioner uses is its FLA or Full Load Amps.
However, on starting an air conditioner consumes more power, referred to
LRA or Locked Rotor Amps. Typically an air conditioner can use 4 times as
much power on start-up, however, it is only momentary (less than 1 second).
Some of the larger single phase air conditioners require soft start devices
to prevent the LRA from being too high.
The problem with using an extension lead is that most domestic types of
extension leads are rated at 10amps maximum but not 10amps continuous. The
extension lead may cause a voltage drop to the air conditioner which may not
allow the air conditioner motor to start and then trip your circuit breaker
because it is drawing its' LRA continuously. Or the air conditioner may
start but if there is a voltage drop then the air conditioner motor will
draw more current (proportional to the drop in voltage) and may overheat
and damage itself over time.
From what you have described your air conditioner is only small so I don't
think that it would be a problem to use a short extension lead. Make sure
the lead is not coiled up and that it doesn't get hot (lead or plugs) and
you use a good lead. Don't use a power board or double adaptor with the
lead either.
Also, don't overload your power points as your circuit breaker (or fuse)
will probably trip when your programming or doing something important on
your computer. It happened to me with an electric heater. :-)
Ruben
Rod Speed
simon lai <si...@gonzo.magellic.com> wrote in message news:slrn940kqb...@gonzo.magellic.com...
Should be ok.
Corse this is someone who powered his entire house from a builder's
temporary supply using a very long extension lead, powering everything
from the full oven and cooktop to the hot water service. Worked surprisingly well.
The startup current for that air conditioner cant be too bad if its got
a standard 10A plug and not a 15A plug with the bigger earth pin.
I use a welder like that anyway, just have an adapter for the plug.
Tony de Groot
Should be OK - especially if you are only using a short extension
cord.
I had a 1kW aircon and ran it from a wall socket on a 3m extension
cord for at least 3 years .. worked fine.
I did check the cord and plug and wall socket for excess heat (as
I also ran the bedlamp (60W) and clock (LED so guess a couple of W).
There was never any sign of any heat buildup.
However - I would make sure that the connections are all in
good condition and not frayed - if you lose some of the conductors
you will end up with a long fuse rather than an extension cord.
Tony.
Alex
"Ken Taylor" <k...@co.nz> wrote in message news:3A40686F...@co.nz...
Arpit
12 amp powerboard, and there is heatup. But not because of power
surges.
Power surges through a piece of 10 amp wire are like putting your hand
rapidly through a candle flame. You don't feel anythingg, but repeated
tries might cause minor damage. Of course, if your power surges were
10000 amps or so, it would be like sticking your hand into a vat of
molten steel then rapidly pulling it out. BAD. There is no reason not
to use an extension cord. If the cord was not rated at 10 amps
continuous, it would be illegal to write merely 10 amps on it. Also
remember that the wiring used for your house is almost identical to te
wiring in an extension wire, so, shoot the salesman.
On Thu, 21 Dec 2000 19:53:44 +0800, Tony de Groot
<ton...@wantree.com.au> wrote:
>Hi,
>
>Should be OK - especially if you are only using a short extension
>cord.
>
>I had a 1kW aircon and ran it from a wall socket on a 3m extension
>cord for at least 3 years .. worked fine.
>
>I did check the cord and plug and wall socket for excess heat (as
>I also ran the bedlamp (90W) and clock (LED so guess a couple of W).
Rod Speed
Arpit <ar...@optushome.com.au> wrote in message news:qe705t0ld2te01a7a...@4ax.com...
> I run a 2.5 kw heater a large tv, large stereo
> system and vcr from a 12 amp powerboard, and
> there is heatup. But not because of power surges.
> Power surges through a piece of 10 amp wire are like putting
> your hand rapidly through a candle flame. You don't feel
> anythingg, but repeated tries might cause minor damage.
Very silly analogy.
> Of course, if your power surges were 10000 amps
> or so, it would be like sticking your hand into a vat
> of molten steel then rapidly pulling it out. BAD.
Even sillier.
> There is no reason not to use an extension cord.
There can be if it prevents the air conditioner starting properly.
> If the cord was not rated at 10 amps continuous,
> it would be illegal to write merely 10 amps on it.
Separate issue entirely to the starting current the airconditioner takes.
> Also remember that the wiring used for your house
> is almost identical to te wiring in an extension wire,
Complete and utter bullshit.
> so, shoot the salesman.
Or shoot you.
Trevor
with a soft start compressor.
The normal mains circuits are only 10A anyway. I assume the $400 was for a
separate 15A circuit for the air conditioner.
Personally I would be worried about running those computers from the same
outlet as the air conditioner as well!
Trevor.
"Alex" <a...@ssc.net.au> wrote in message
news:92cqgp$2m6b$1...@news.interpacket.net...
Arpit
wrote:
>
>Arpit <ar...@optushome.com.au> wrote in message news:qe705t0ld2te01a7a...@4ax.com...
>
>> I run a 2.5 kw heater a large tv, large stereo
>> system and vcr from a 12 amp powerboard, and
>> there is heatup. But not because of power surges.
>
>> Power surges through a piece of 10 amp wire are like putting
>> your hand rapidly through a candle flame. You don't feel
>> anythingg, but repeated tries might cause minor damage.
>
>Very silly analogy.
>
>> Of course, if your power surges were 10000 amps
>> or so, it would be like sticking your hand into a vat
>> of molten steel then rapidly pulling it out. BAD.
>
>Even sillier.
>
>> There is no reason not to use an extension cord.
>
>There can be if it prevents the air conditioner starting properly.
>
>> If the cord was not rated at 10 amps continuous,
>> it would be illegal to write merely 10 amps on it.
>
>Separate issue entirely to the starting current the airconditioner takes.
>
>> Also remember that the wiring used for your house
>> is almost identical to te wiring in an extension wire,
>
>Complete and utter bullshit.
I think that you may be thinking of that huge 30 to 40 amp wire which
runs around the walls of the house.
I am talking about the 10 amp wires used to hook a power outlet to
those wires.
David Emrich
"Arpit" <ar...@optushome.com.au> wrote in message
news:56s25toahrrrbp3us...@4ax.com...
> On Mon, 1 Jan 2001 20:26:55 +1100, "Rod Speed" <rod_...@yahoo.com>
> wrote:
>
> >
> >Arpit <ar...@optushome.com.au> wrote in message
news:qe705t0ld2te01a7a...@4ax.com...
> >
> >> I run a 2.5 kw heater a large tv, large stereo
> >> system and vcr from a 12 amp powerboard, and
> >> there is heatup. But not because of power surges.
No, but because the 2.5KW heater is already pulling over 10A, even more on
startup. Forget about the VCR, but the large stereo might account for
another amp or two.
[snip]
> >> There is no reason not to use an extension cord.
Except that many extension cords are rated at 7.5A (or 1800W) a few at 10A
(2400W) and very few more than that. Ones that are rated higher than 10A
have to have heavy duty plugs and sockets (the ones with bigger earth pins).
> >> Also remember that the wiring used for your house
> >> is almost identical to te wiring in an extension wire,
> >
> >Complete and utter bullshit.
> I think that you may be thinking of that huge 30 to 40 amp wire which
> runs around the walls of the house.
> I am talking about the 10 amp wires used to hook a power outlet to
> those wires.
There is "NO 10 amp wire to hook an outlet to those main wires"... It's the
same thickness right from the outlet back to the circuit
breaker/switchboard,... anything else is illegal. And that's usually rated
to 25A.
> >> so, shoot the salesman.
> >Or shoot you.
Put the guns away folks, no-one here really seems to know exactly what
they're talking about, but then, so far, no qualified electricians have
commented. It's no point shooting someone for not knowing something. There
IS a point for 'shooting' someone who says things as gospel when they don't
really know for sure.
[snip]
> >> >I had a 1kW aircon and ran it from a wall socket on a 3m extension
> >> >cord for at least 3 years .. worked fine.
That's because it's way under 10A. In fact it's under 5A.
> >> >> I want to install a small airconditioner in
> >> >> a room in my house - the window mounted variety.
> >> >>
> >> >> Specs say it draws 0.97kW, 4.1A @ 240V. The cord
> >> >> that comes with the unit is 300mm long, insufficient
> >> >> to reach the nearest powerpoint. My query to the
> >> >> airconditioning installer as to whether an extension
> >> >> cord could be used was met with shakes of the head
> >> >> and disbelief - a "can't be done" sort of a response.
That is more likely to be for the fact that it's likely to trip the RCD
breakers on standard points.
> >> >> I was always under the impression that a reasonable
> >> >> extension lead could handle 10 amps, and this one
Many are only 7.5A. Still plenty.
> >> >> Is there something about the way air conditioners
Yes, startup currents can be high, but not over 10A for a 4.1A running
current (at least not for long enough to matter).
Dvaid.
Rod Speed
Arpit <ar...@optushome.com.au> wrote in message news:56s25toahrrrbp3us...@4ax.com...
>>> I run a 2.5 kw heater a large tv, large stereo
>>> system and vcr from a 12 amp powerboard, and
>>> there is heatup. But not because of power surges.
>>> Power surges through a piece of 10 amp wire are like putting
>>> your hand rapidly through a candle flame. You don't feel
>>> anythingg, but repeated tries might cause minor damage.
>> Very silly analogy.
>>> Of course, if your power surges were 10000 amps
>>> or so, it would be like sticking your hand into a vat
>>> of molten steel then rapidly pulling it out. BAD.
>> Even sillier.
>>> There is no reason not to use an extension cord.
>> There can be if it prevents the air conditioner starting properly.
>>> If the cord was not rated at 10 amps continuous,
>>> it would be illegal to write merely 10 amps on it.
>> Separate issue entirely to the starting current the airconditioner takes.
>>> Also remember that the wiring used for your house
>>> is almost identical to te wiring in an extension wire,
>> Complete and utter bullshit.
> I think that you may be thinking of that huge 30 to 40
> amp wire which runs around the walls of the house.
> I am talking about the 10 amp wires used
> to hook a power outlet to those wires.
You've mangled that totally. There is a TPS which runs around
the GPOs, what you called 'that huge 30 to 40 amp wire'. Its
nothing like the wire in extension cords.
The wire in the TPS is screwed into the ferrules in the back of the GPOs.
Rod Speed
David Emrich <dem...@ihgtech.com.au> wrote in
message news:92s65q$rnf$1...@yeppa.connect.com.au...
> Arpit <ar...@optushome.com.au> wrote
>>>> Also remember that the wiring used for your house
>>>> is almost identical to te wiring in an extension wire,
>>>Complete and utter bullshit.
>> I think that you may be thinking of that huge 30 to
>> 40 amp wire which runs around the walls of the house.
>> I am talking about the 10 amp wires used
>> to hook a power outlet to those wires.
> There is "NO 10 amp wire to hook an outlet to those main wires"...
>It's the same thickness right from the outlet back to the circuit
> breaker/switchboard,... anything else is illegal.
Yes.
> And that's usually rated to 25A.
Nope. Most obviously with fused power circuits.
>>>> so, shoot the salesman.
>>> Or shoot you.
> Put the guns away folks,
No thanks.
> no-one here really seems to know exactly what they're talking about,
You're in no position to say that, as you admitted yourself.
> but then, so far, no qualified electricians have commented.
You dont know that either. And you dont need to be a qualified electrician
to be able to read the wiring rules. There's pretty simple at that level.
> It's no point shooting someone for not knowing something.
It was a frivolous remark, silly.
> There IS a point for 'shooting' someone who says
> things as gospel when they don't really know for sure.
Yep, which is why I said 'shoot you'
Trevor Bird
"equations" etc
Try running a 30 amp heater on 10 amp extension lead and see what starts
heating up first
Does any one want to guess what sort of tolerances are involved in this sort
of stuff
Please !! take all things into considerations , surge currents must large
and for long duration we are talking about rugged equipment now not
sensitive millamps or microamps
Come on !! what is the equation for work out how to blow a 10 A fuse with
surge current
remeber the time period has an effect too
Problem I can draw 100 A @ 240 V on peice of copper 0.18mm dia by 50mm long
in "ice"
Hey problem solved with Air Conditioner plug the barsted in all it can do is
blow a fuse !!
No Problem a storm in a tea cup !!!!!!!!!!!!!
Trevor wrote in message
<3a513920$0$7507$7f31...@news01.syd.optusnet.com.au>...
Arpit
discussion and also knows what a power surge is.
Supposing the surge current of the air conditioner is one amp lower
than the fuse ratilng, but is considerably higher than the wire
rating.
I run a 16 amp Air COnditioner off several 10 amp powerboards, as well
as a few computers, about 3 amps of sound equipment, and another 5
amps of transformers. No heatup Whatsoever, simply because the air
conditioner only draws 16 amps in the first 15 seconds of starting up.
Consider an old laser printer which was in my house. It drew about 100
watts constantly, but occasionally, to drive the heater, it would draw
2400 watts.
>Please !! take all things into considerations , surge currents must large
>and for long duration we are talking about rugged equipment now not
>sensitive millamps or microamps
exactly
>Problem I can draw 100 A @ 240 V on peice of copper 0.18mm dia by 50mm long
>in "ice"
HA, YOu would need 4 gauge wire to do that.
Ken Taylor
each other. :)
I thought that this thread had finally died, but here's a few points:
Starting currents for compressors aren't 'minor surges'.
How do you propose to 'limit the current to less than 10 Amps'?
What 'recommended length' of extension cord are you talking about?
Why doesn't Ohms Law apply at less than 10 metres? Doesn't current drawn
and wire gauge come into it?
It's a single use extension lead in this case - what other appliance is
going to be plugged in also?
What air-con salesman gets a commission for convincing you to install
another power point?
How come suddenly a 7.5 metre cable isn't okay when short you previously
said Ohms Law wasn't a problem under 10 metres?
I'm sorry, but you've combined a whole heap of out-of-context truths to
get a mish mash.
Extension leads and high current appliances are a problem in the house
without a bit of thought being applied. Simon (original poster) made a
wise choice by buying an air-con which had a long enough lead and was
designed to plug in to a normal household 10A outlet.
Ken
John Vance wrote:
>
> There seems to be a lot of ignorant electronics people here (here's
> another) . If you use a standard extension cord rated at 10 Amps, any
> minor surge wont upset it. When you limit the current to less than 10
> Amps. An extension cord which is over the recommended length will,
> because of Ohms law or resistance start to show a voltage drop. This
> should not happen at 10 meters or less. (less than ten percent) The
> problem may come when some one else plugs another appliance in which
> will may draw too much current and cause the voltage to drop and stall
> the compressor. (It cant draw enough starting current. Salesmen will
> pretend they're ignorant to earn extra commission to get a power point
> installed. They are ignorant to the fact that you know all of this
> stuff. So get an extension cord and make it just long enough to do the
> job. The cheap extension cords available from places like target may
> not be suitable if they're rated at 7.5 amps as I've seen some.
> They're for stereo systems and light duty appliances. To be sure, get
> a short length of 15 Amp extension cable and make one up for the short
> length you need. It wont cost much and will give you all the current
> you need to start up. The larger Electricians shops should be able to
> sell you a short length. (The cord on your air conditioner should give
> you a clue to how thick it should be). Otherwise ignore me and get a 3
> meter Extension cord with 10 rating .
> PS The voltage drop may still play a part of your house wiring is old.
malcor
"Ken Taylor" <k...@co.nz> wrote
> Hi John. Yes, the beauty of the Internet - the ignorant can miseducate
> each other. :)
>
> I thought that this thread had finally died, but here's a few points:
> Starting currents for compressors aren't 'minor surges'.
Just to add that the electric drive motor for the compressors are inductive
and on start-up have a very low power factor. As the motor gets up to speed,
and full load, the power factor approaches unity. What that means is that
for a given amount of power required more current is actually drawn (on
start-up). Unless the compressor is an inverter type (variable speed scroll
compressor). They have a much better power factor on start-up, but due to
the electronics not the motor.
Ruben