3 phase or single phase
Brian N. Blazer
house. One of the buildings I am looking at has the ability for 3 phase.
For my welder and plasma cutter this would be a good but not necessary
thing. Currently none of my woodworking tools are 3 phase, but that could
change.
My questions are this...
1) Generally, what is the cost difference in kw/hr 3 vs.. single
2) Are woodworking power tools performance improved with 3 phase?
3) Would you do it if you could?
Thanks,
Brian
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Grinmonger
service to your area-cannot make 3 out of single ph though. If sensitive
equipment to be used, may require insulated, isolated grounding which also can
be done on single ph. Highly recommended if computers, lasers,etc to be
connected, but thats a whole another issue. Cannot help with costing...maybe
another groupie will opine.
JK
Uniqueasaur.
> 1) Generally, what is the cost difference in kw/hr 3 vs.. single
None, you are charged by the watt.
> 2) Are woodworking power tools performance improved with 3 phase?
No, but it allows you to use smaller breakers and gauge of wire due to the
smaller amp draw.
> 3) Would you do it if you could?
Yes.
You then have any and all power options available to you. I go to many
auctions and I see three phase equipment go for peanuts where the same thing
in single phase goes for five times as much, because most home/small shop
people don't have 3 phase power, and big shop people don't go to auctions
looking for bargains.
I saw a 24" 10 hp, big ass, cast iron, minty fresh, planer go for $800
dollars because it was three phase and there were only hobbyists at the
auction.
If it costs less than $2000 for three phase power, you can get the back in
no time by buying used equipment.
Thanks,
David.
Every neighbourhood has one, in mine, I'm him.
Remove the "splinter" from my email address to email me.
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Marrio Lanza
definitely necessary. Large horse power motors are not made in single. I
had the advantage of 600 volts in three phase. I bought one of my three
Tannewitz table saws in 550 volts at an auction for $1500 that would have
gotten $6000 if it were 220. So I have to agree with David. Because of the
600 volts in my shop, I did use less amps for that machine only. It was
from Canada where 600 volts is more common. If you are interested in heavy
clunky machinery and have the room as well as first floor access, I would
definitely invest in three phase. I wish that I had the room and the power
in my present shop now that I am retired. I still have a Tannewitz table
saw that I had converted to single phase but I did spend a few dollars for
that. The trade off was that I kept a 16" 5hp machine that I consider the
Rolls Royce of table saws. Wish that I could have kept my 16" Northfield
jointer too but that was big enough to land a Cessna 150 on. I now have an
8" Delta DJ20 which I consider several steps above its competition in single
phase.
Nice talking to you.
Best,
--
Mario Lanza
71Sandman
power. Conversely single phase equipment cannot be wired to run on three
phase power.
1) A transformer is required to convert 3 phase to single phase except 208
3phase WITH a neutral wire.
2) A special converter such as a roto-phase unit is required to convert
single phase to 3 phase.
If the service is 208VAC 3 phase WITH A NEUTRAL (Neutral is required), then
there is nothing to be concerned with. You get the best of both worlds. Any
leg of the 208 to neutral will give you your normal 110VAC power, however
220 is not available. If the 3 phase power is something like 480V then you
will need a step down transformer for all of your single phase needs. There
are a lot of factors to consider and there is no "best" answer to your
question. Below are a couple of websites that you can look at to do some
research. As far as performance is concerned, YES the 3 phase will provide a
more constant power source and therefore provide higher torque and smoother
operation over standard single phase tools. 3 Phase motors do not require
starter capacitors or brushes so they tend to live longer and run quieter.
If you only have single phase power available you can still convert to 3
phase with special equipment. Generally speaking, it is cheaper to convert 3
phase to 1 phase. Some of the links below are for converters.
If you are serious get an electrician handbook such as
http://www.amazon.com/exec/obidos/ASIN/0020364253/qid=1010291283/sr=2-2/ref=
sr_2_9_2/002-1344961-2804844 so you can get a better idea of what your
connection options are.
http://www.howstuffworks.com/power.htm
http://www.isomatic.co.uk/3phConverter.htm
http://www.phaseconverter.com/remanufacturedconverters.html
Good luck
Thomas Jackson
"Brian N. Blazer" <br...@brianblazer.com> wrote in message
news:3c37a...@goliath.newsgroups.com...
> I am looking in to putting a shop together to get my hobby away from the
> house. One of the buildings I am looking at has the ability for 3 phase.
>
> For my welder and plasma cutter this would be a good but not necessary
> thing. Currently none of my woodworking tools are 3 phase, but that could
> change.
>
> My questions are this...
>
> 1) Generally, what is the cost difference in kw/hr 3 vs.. single
None.
>
> 2) Are woodworking power tools performance improved with 3 phase?
3 phase induction motors are inherently simpler than single phase so they
tend to last longer. Bearings are the first to go rather than it being a
race between the bearing and the windings.
>
> 3) Would you do it if you could?
You bet!
>
> Thanks,
> Brian
Tom Jackson
Engineered Conversions of Woods into Sawdust
L. M. Rappaport
check with your electric utility before making a decision. For
example, up here in northern NH, Public Service (the electric utility)
will only provide 3 phase at commercial rates which are very high and
require a demand meter which easily makes them higher. The co-op (New
Hampshire Electric Co-op) is similar and the cost from both utilities
to provide 3 phase is staggering.
No doubt 3 phase motors run cooler and cost less. However, you might
want to consider a converter before getting commercial if your
electric utilities are similar.
Larry
--
ra...@lmr.com
"Brian N. Blazer" <br...@brianblazer.com> wrote (with possible
editing):
Ross
this week. The box was not much more than single phase, however the
breakers are about $75 for a 20 amp. I found a 30 amp on Ebay for $30.00.
--
Ross Canant
http://www.myoldtools.com
"Tom Kendrick" <tken...@stealthaccess.net> wrote in message
news:aWA4PPUSGLtzeK=NFCFpX...@4ax.com...
> Some questions to guide you -
> Will the service be "demand" or metered as is done for a
> residence? Demand makes you pay for the highest use during a billing
> cycle.
> Single phase breaker boxes are very common, however 3-phase
> breaker boxes are more expensive and are not usually stocked. They are
> manufactured when ordered.
> Should you need/want to relocate later, you could become
> "locked into" 3-phase and reduce your alternatives for new sites if
> your equipment could not function on single phase power.
> Consult an electrician about his rates and equipment costs as
> though you will hire him to wire it for you. The difference may be
> significant.
> Tom
Charles Self
>You have lots of good answers here - I'll just add that you should
>check with your electric utility before making a decision. For
>example, up here in northern NH, Public Service (the electric utility)
>will only provide 3 phase at commercial rates which are very high and
>require a demand meter which easily makes them higher. The co-op (New
>Hampshire Electric Co-op) is similar and the cost from both utilities
>to provide 3 phase is staggering.
>
>No doubt 3 phase motors run cooler and cost less. However, you might
>want to consider a converter before getting commercial if your
>electric utilities are similar.
All the answers were fine, including Larry's. I've got a friend who has a
cabient shop, and he only uses single phase. Reason: he is the only industry
along a stretch of road some 18 miles long that could use 3 phase. At one
point, he wanted to go 3 phase and picked up a bunch of used gear in
anticipation. He's now trading/selling the gear, because the local power
barons told him it was far, far too costly to run a line to just feed one small
shop (3-4 employees).
But, IIRC, the original poster wanted to know if he should lease a building
with 3 phase already in it. I would, because it gives you the option of using
single or 3 phase, and 3 phase, as many others have noted, gives access to
literally tons (sometime in one piece of gear) of equipment at prices of not
much more than a quarter a pound.
Charlie Self
Brian N. Blazer
power conglomerate and find out about rates.
Hearing about all of the auctions where 3 phase equipment goes for the
cheap, I am REALLY interested now.
Brian
"Brian N. Blazer" <br...@brianblazer.com> wrote in message
news:3c37a...@goliath.newsgroups.com...
Jim Wilson
> single ph though...
Three phase power can be generated from single phase easily, using readily
available converters of several types. Many home shop enthusiasts (like
me) make their own rotary converters. For further info, googlize
"converter rotary OR static OR VFD" in rec.crafts.metalworking.
www.google.com/advanced_group_search
Jim
Dave-Sandra
Snip
If the service is 208VAC 3 phase WITH A NEUTRAL (Neutral is required), then
there is nothing to be concerned with. You get the best of both worlds. Any
leg of the 208 to neutral will give you your normal 110VAC power, however
220 is not available.
BUT..I must politely disagree.......... you can run a 220 volt motor on 208
volts although it will not run at top efficiency it will run
Charles Erskine
transformer and matching breaker panel. This was capable of producing
208V 3-phase, 220V 1-phase and 110V 1-phase from the same panel.
"Brian N. Blazer" <br...@brianblazer.com> wrote in message news:<3c38b742$1...@goliath.newsgroups.com>...
71Sandman
reduce the overall starting torque. This in turn generates more heat in the
motor windings. While not immediately evident, the reduced voltage will
reduce the life of your motors. The choice of course, is yours.
RWatson767
>3 phase or single phase
Without even looking at the other posts I would go with 3 pahse in a heartbeat.
And all because of electrical performance. I would further extend it to the
house if possible.
For morors the controls etc to get the motor started are as simple as pie.
And no starting circuitry in the motors. Just hit them with the 3 phase and
away they go. To reverse just swap any two leads.
The down side is that the power panel will be more expensive. I would go to a
place like a demoilition store. In my town I could get everything I need for
$200.00. I am sure you can do as well on Ebay.
Bob AZ
Bob AZ
Lew Hodgett
> I've worked in a factory that had a 3-phase "4-wire delta secondary"
> transformer and matching breaker panel. This was capable of producing
> 208V 3-phase, 220V 1-phase and 110V 1-phase from the same panel.
Not quite.
A 208V/3ph/4w service provides 208V/3ph, 120V/1ph, but not 220V/1ph.
It is a square root of 3 thing.
--
Lew
S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
Visit: <http://home.earthlink.net/~lewhodgett> for Pictures
71Sandman
208 3 phase use for 220 single phase will also suffer from improper phase
relationships. You see, any two phases on a 3 phase power source run 120
degrees apart in relation to each another. In true 220 1 phase the power
phases run 180 degrees apart yielding a much higher peak to peak voltage.
The effects are not just 12 volts as it might appear. And now Mr. Science
will shutup. ;-)
71Sandman
transformer stepped that down to 208/3/60 then he would have all three
available, but that would be the only way. As for all in the same breaker
panel, that must be a custom breaker panel with to isolated 3phase busses in
it. The 120Vac power would only be available from the 208 buss.
Lew Hodgett
> > Not quite.
> >
> > A 208V/3ph/4w service provides 208V/3ph, 120V/1ph, but not 220V/1ph.
> >
> > It is a square root of 3 thing.
What I forgot to add is that over the years, sold quite a few "Buck-Boost"
transformers to solve this very problem.
As an example, very common for shopping centers to be built with 208V/3ph/4w
which provides not only the single phase but also the 3 phase for the
heating and cooling loads.
When 208V was first introduced to shopping center builders, long before
everybody got their act together and ordered the right equipment, a lot of
mechanical equipment (air conditioning, refrigeration, etc) would arrive at
the job site with 230V/3ph motors.
Rather than send the equipment back and delay the construction cycle,
buck-boost x'fmr's came to the rescue.
SFWIW.
Jack Lane
Actually, you were right the first time. If you were to connect one lead
of a battery operated oscilloscope to phase A and the refrence lead to phase B
(for instance) you would see a near perfect sinusoidal voltage with an RMS
value of 208 volts. Connect that same oscilloscope to your 220 volt single
phase source and you would also see a near perfect sinusoid with an RMS value
of 220 volts. In the US, the line voltage is always given as the RMS voltage,
not the peak voltage.
The peak voltage is larger than than the RMS voltage (for a sinusoid) by a
factor of sqrt(2). In the case of your 220, the peak voltage is actually
220 * 1.414 = 311 volts. The peak voltage between phase A and phase B for
the 208 volt 3 phase system is 208 * 1.414 = 294 volts (a difference of 12
volts RMS and 17 volts peak). The peak to peak voltage is twice the peak
voltage. Your 220 volt line actually swings from -311 volts to +311 volts,
while the single phase of the 208 volt 3 phase system swings from -294 volts
to +294 volts.
The 120 volt phase shift is only seen when comparing any two phases in a
3 phase system. For instance, the phase A to phase B voltage is 120 degrees
out of phase with respect to the phase B to phase C voltage. Likewise, the
phase A to neutral voltage is 120 degrees out of phase to the phase B to
neutral voltage, etc.
Jack
P.S. If you are interested in what is meant by RMS, it stands for "root mean
square". The idea is that if you connected a 1 ohm resistor to a DC voltage
of say 10 volts you would dissipate 10 watts of power. Connect that same 1
ohm resistor across a sinusoidal voltage with a peak value of 10 volts and
you would dissipate less than 10 watts if you averaged the power over one
cycle. This makes sense since the absolute value of the voltage is only at
that 10 volt level for brief moments during the cycle, and is less than 10
volts for most of the cycle. It turns out that for this example, the average
power dissipated is 10/sqrt(2) = 10/1.414 = 7 watts. Hence a sinusoidal
voltage that has a peak value of 10 volts is said to be 7 volts RMS.
I hope this isn't too confusing :-)