Arc welder question

[James]

Hello everyone

If I connect a 415 volt single phase arc welder to a 240 volt supply,
will it still weld ok? Im guessing it will be different but to weld
something with it connected to 240 volts, will I just need to crank it
up more? There are no fans or other accessories inside connected to
the main supply.

on a second note, which is likely to blow first, a 32 amp C curve
circuit breaker or the 45 amp HRC supply authority fuse? Basically im
wondering if I can get away with temporarily connecting a 450 amp
stick welder up to the stove connection in a unit for some building
work. Name plate reads(input): 415 volt, single phase, use 45 amp
fuse, max short circuit input current 109 amps.

I got asked this not long ago to see if it was do-able, not really the
best option, but I did get thinking about whether it would in fact
work. I am in Australia.

any input appreciated.

thanks
James

 

[mikegw]

Hello everyone

thanks
James

Would it be easier to hire a 3 phase generator or a single phase welder for
the job?

Mike

 

[NCR Employee]

Single phase 415 is 240
I would say why they use a three phase outlet is the get Hi current carrying
capacity.
Phillip

Unfortunately - not in this case - the connection is accross any two phases
to get 415v single Phase
I doubt if you could do much welding as the open circuit voltage will only
be 240/415 of what it should be - 57% approx, making striking and sustaining
an arc unlikely.
If the max input short circuit current is rated at 109A, I would suspect
that the current draw is a bit too high for a domestic suplyanyway as the
power factor of this welder is likely to be very poor.

Dave

 

[Rheilly Phoull]

Check for connections to use it on 240v. Most of this type of welder usually
are made that way.
(Should be shown on connection cover or connection plate on welder)

 

[grames]

I have owned a few welders that have a setup inside where you can
change a couple of connections inside to swap from 415 to 240v.

It would be worth having a look inside the case.
This is quite common.

Grames

 

[James]

Thanks for your replies everyone, much appreciated. This welder is a
straight 415 volt unit, no taps. Normally I'd just do it properly and
get 3 phase power connected but this is only for a smallish job.
Theres actually 3 phase on the site, but its split up into single
phase supplies to each individual unit. So theres no non-dodgy way of
getting 415 volts Just be getting a genset and usign the three
phase mig instead I think.

Just while talking about power stuff, does the *average* american
house really have a 200 amp supply? Thats really huge compared to
houses here and aircon is really common too as is electric hot water.
Normal houses in the suburbs here have an 80 amp service fuse. We have
a 3 phase supply to our house here as do a lot of houses in the
immediate area, mainly for 3 phase bore pumps (semi rural area).

anyway, tahnks again

James

 

[John Gilmer]

Just while talking about power stuff, does the *average* american
house really have a 200 amp supply?

New stand alone homes and service upgrades (where an only fuse box is
replaced) typically have a 200 amp panel.

The actual draw is almost always less than 100 amps. (We have had
"emergency" service provided by a auto-transformer with a 100 breaker. We
lived more or less as we always do and the breaker didn't trip.)


The BIG power consumers are the HVAC system (in cold weather, most new homes
around here (Northern Neck of Virginia) use 100% resistance heating. The
heat pump may be running but just can't put out much.) In a worse case
with a heat pump in defrost and all the resistance heaters switched in, the
HVAC system COULD draw about 100 amps by itself. Throw in the water heater
(20 amps), water pump (10 amps), stove (40 amps), and some of the small
stuff that draws about 10 amps (hair dryers, irons, whatever) and you can
get close to 200 amps.

Thats really huge compared to
houses here and aircon is really common too as is electric hot water.
Normal houses in the suburbs here have an 80 amp service fuse. We have
a 3 phase supply to our house here as do a lot of houses in the
immediate area, mainly for 3 phase bore pumps (semi rural area).

Well, if you have 3 phases, your 80 amps is equivalent to our 120 amps. (3
x 80 = 2 X 120).

 

[Russ]

Thanks for your replies everyone, much appreciated. This welder is a
straight 415 volt unit, no taps. Normally I'd just do it properly and
get 3 phase power connected but this is only for a smallish job.
Theres actually 3 phase on the site, but its split up into single
phase supplies to each individual unit. So theres no non-dodgy way of
getting 415 volts Just be getting a genset and usign the three
phase mig instead I think.

Just while talking about power stuff, does the *average* american
house really have a 200 amp supply? Thats really huge compared to
houses here and aircon is really common too as is electric hot water.
Normal houses in the suburbs here have an 80 amp service fuse. We have
a 3 phase supply to our house here as do a lot of houses in the
immediate area, mainly for 3 phase bore pumps (semi rural area).

I'm probably missing something, but isn't American power 110 volts, so to
get as many watts power, they'd need twice the amps as our 240v system?

On a similar note, while I've been to the US a few times, I've never taken
the time to look - do they have a MEN (Multiple Earth Neutral) system? Do
they require RCD (Residual Current Device) breakers on new houses?

Inquiring minds and all that.

Russ.

 

[Rod Speed]

The BIG power consumers are the HVAC system (in cold weather, most
new homes around here (Northern Neck of Virginia) use 100% resistance
heating. The heat pump may be running but just can't put out much.)

What's the external temps where you still get useful heat pumping ?

I currently use 100% resistance heating and was considering
a heat pump. I have gas as an available alternative.

 

[User 1.nospam]

Yes, and it would be single phase. 240/120 from a center tapped xfmr with
the center (neutral) solidly grounded. (National electric code requires it)
Household appliances commonly operate at 120volts. (exception: electric
clothes dryer, electric cookstove) Typically a home is supplied by a 15Kw,
pole mounted transformer.

I believe that 3 phase to a single family residence is a no-no, though
three phase to an apartment building is quite common.

Three phase would be a vast improvement, but the experience level of
electrical installers varies WIDELY here in the US and there are many
"electricians" here who would not know how to install it and have it work
properly.

I live in Kentucky and there are some superb electricians here....there are
also some well-meaning individuals whose eyes roll back in their heads when
you start talking about wiring a 3-way light switch.

As for aluminum wiring, the price difference with copper is so small anymore
that we dont see much of it. Here in KY is it illegal in small sizes
(branch wiring), though I believe that you could still use it in larger
sizes for feeder circuits and it is very common on incoming service
conductors. The power companies all use aluminum for their conductors
unless they are very close to the ocean.

Feelings against aluminum runs high in Ky due to the fact that it was found
to be a major contributor to a "supper club" fire several years ago that
killed over 100 people.

 

[Spehro Pefhany]

They only run 110 volts, so the extra current is needed. Your 80 amps is
actually almost the same in terms of power supplied to the house.

AFAIK, the panel rating is at 240VAC. All the heavy loads (eg. aircon,
water heater, clothes dryer, range, oven, heat pump, spa heater, etc.)
in American and Canadian residences are wired across the 240V lines.

Best regards,
Spehro Pefhany

 

[Russ]

OK. When we have a 100 amp service that's 100 amps for each leg. IOW:
Our 100 amp service IS at 240 volts (just like yours.)

Generally speaking (and exactly speaking in King George, Virginia) the
120/240 output of the transformer has neutral bonded to the neutral of the
high voltage feed and to a ground rod at the pole or at the transformer.

In addition, the neutral is bonded to a ground rod (or two) at the "service
entrance". The bonding connection is at the meter base.

GFCI (Ground Fault Current Interruptor) are dirt cheap in the 120 volt 20
amp basic model. GFCI circuit breakers for popular service panels in the
single pole version are relatively inexpensive.

Two pole GFCIs are less than $100 and are used for things like hot tubs.

I hope I addressed your question. We have two cultures divided by a single
language!

Thanks - that pretty much covers it - it all seems identical to Oz (although
I am thoroughly unqualified to comment), except for the dual feed trick. As
others have said, the only variation here tends to be the option of three
phase, but isn't very common in domestic situations, unless there's a
specific requirement (like a 3-phase beer fridge for serious drinkers).

Russ.