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Welder Hook up-electrical requirements
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coino...@comcast.net
Dec 12, 2006, 11:26:21 AM12/12/06
to
First off-I'm a welder-not an electrician! I just purchased a used
Miller 351 Syncrowave welder for my garage. After
checking Miller Electrics website about the electrical service guide
for this
machine http://www.millerwelds.com/om/o354g_mil.pdf my questions are-
If I run
a wire frome my panel box and install a sub panel in the garage-What
size wire
to use from my panel box. Also what size breaker? It looks to me to
need a 100 amp breaker and #2 copper wire. Is that right? I have the
manual for the welder dowloaded from Miller Electric. I had an
electrical contractor tell me he cannot tell the draw, breaker, or hook
up requirements from this manual. It looks to me to have all the info.
The electrical contractor tell me I would need to up my 200 amp service
to 350 amp. Then run a sub-panel for the welder. This is all more money
than I can spend. Anyone have a similar machine that can advise hook
up? Any info. would be great. Thanks, Matt
Miller 351 Syncrowave welder for my garage. After
checking Miller Electrics website about the electrical service guide
for this
machine http://www.millerwelds.com/om/o354g_mil.pdf my questions are-
If I run
a wire frome my panel box and install a sub panel in the garage-What
size wire
to use from my panel box. Also what size breaker? It looks to me to
need a 100 amp breaker and #2 copper wire. Is that right? I have the
manual for the welder dowloaded from Miller Electric. I had an
electrical contractor tell me he cannot tell the draw, breaker, or hook
up requirements from this manual. It looks to me to have all the info.
The electrical contractor tell me I would need to up my 200 amp service
to 350 amp. Then run a sub-panel for the welder. This is all more money
than I can spend. Anyone have a similar machine that can advise hook
up? Any info. would be great. Thanks, Matt
Steve B
Dec 12, 2006, 12:00:21 PM12/12/06
to
<coino...@comcast.net> wrote in message
news:1165940781.7...@80g2000cwy.googlegroups.com...
I'd ask another electrician. I'm surprised this guy didn't insist on
replacing your garage, too. ;-)
Steve
Robert Ball
Dec 13, 2006, 12:15:19 AM12/13/06
to
Assuming you are in the USA and have 240V available at a residential
panel, you would draw about 112A so you don't want to run the air
conditioner, electric stove, dryer, and welder all at the same time on a
200A panel. But fortunately most welding is short term rather than a
continuous load, and you rarely run the rated output of the welder so
the load is less (I doubt you'll do much welding at 420A). You don't
need to install a subpanel, you can run a dedicated circuit to your
welder plug. The electrical code has some exceptions for welders due to
the short term loads; ask an electrician to look at the code and see
what exceptions apply to your situation. Many libraries will have
copies of the codes that you can read and photocopy selected pages.
Knowledge is power. The exceptions will vary, depending on which code
is used by your city, and your particular situation. In most cases the
shop or garage must be a separate building or have a fire wall between
it and the house to qualify for the exceptions but that wall isn't much
more than a sheetrock wall (I'm generalizing to simplify; not defining a
one hour rated wall). The wire size is determined by both the load and
the distance; the wire size has to be increased to compensate for losses
that would occur on a long run. My 300A inverter machine calls for #8
wire but I had to use #6 because it is more than 40' from the panel to
the outlet. Remember that wire size goes up as American Wire Gauge (AWG)
number goes down. My breaker is oversized as allowed by an exception in
the code, which helps to prevent nuisance trips due to surges at
start-up. I had to show the building inspector the exception in the
code before he would believe me. He was a nice guy, just didn't see
many welder outlets in any year. That exception doesn't apply is the
machine is rated for 100% duty but I doubt that you'll see a single
phase machine with 100% duty at nominal rated output. Long answer to a
short question.
panel, you would draw about 112A so you don't want to run the air
conditioner, electric stove, dryer, and welder all at the same time on a
200A panel. But fortunately most welding is short term rather than a
continuous load, and you rarely run the rated output of the welder so
the load is less (I doubt you'll do much welding at 420A). You don't
need to install a subpanel, you can run a dedicated circuit to your
welder plug. The electrical code has some exceptions for welders due to
the short term loads; ask an electrician to look at the code and see
what exceptions apply to your situation. Many libraries will have
copies of the codes that you can read and photocopy selected pages.
Knowledge is power. The exceptions will vary, depending on which code
is used by your city, and your particular situation. In most cases the
shop or garage must be a separate building or have a fire wall between
it and the house to qualify for the exceptions but that wall isn't much
more than a sheetrock wall (I'm generalizing to simplify; not defining a
one hour rated wall). The wire size is determined by both the load and
the distance; the wire size has to be increased to compensate for losses
that would occur on a long run. My 300A inverter machine calls for #8
wire but I had to use #6 because it is more than 40' from the panel to
the outlet. Remember that wire size goes up as American Wire Gauge (AWG)
number goes down. My breaker is oversized as allowed by an exception in
the code, which helps to prevent nuisance trips due to surges at
start-up. I had to show the building inspector the exception in the
code before he would believe me. He was a nice guy, just didn't see
many welder outlets in any year. That exception doesn't apply is the
machine is rated for 100% duty but I doubt that you'll see a single
phase machine with 100% duty at nominal rated output. Long answer to a
short question.
coino...@comcast.net
Dec 13, 2006, 7:42:38 AM12/13/06
to
After I posted my question here I contacted Miller Electrics online
tech service. They sent me this. The electrical service guide for a
Syncrowave 351 shows that at
50/60HZ single phase, input voltage at 230 without power factor
correction you
will need a 125 amp time delay or a 125 amp normal operating breaker.
Minimum input conductor size in AWG is number 4.
Maximum input conductor length in feet (117)
tech service. They sent me this. The electrical service guide for a
Syncrowave 351 shows that at
50/60HZ single phase, input voltage at 230 without power factor
correction you
will need a 125 amp time delay or a 125 amp normal operating breaker.
Minimum input conductor size in AWG is number 4.
Maximum input conductor length in feet (117)
So my next question is- Is the proper way to do
this to- Put receptacle in garage-run #2 copper cable back to a breker
box with a 125 amp breaker-then run to main in my panel box? Or put the
breaker box with the 125 amp breaker in the garage-the run the #2 to my
main panelbox? Thanks, Matt
Grant Erwin
Dec 13, 2006, 10:02:10 AM12/13/06
to
So you want to pull off 125 amps from your 200 amp panel to your garage, and
then rout that to your welder? The normal way is to put a 125 amp breaker in
your house panel (if you have room, good luck!) and then pull the no. 4 wires
out of your house panel and rout them to your garage. At that point you could
install a subpanel, or you could just run the wire right to your welder plug.
Most guys need more power to a home garage anyway, so this is a good upgrade.
Your electrician might be right, though, you may not be able to pull another 125
amps from your existing panel. Go look at it. Most US panels are completely
full. Not only that, but I don't even know if you can buy a 125 amp single phase
breaker. That's a huge circuit.
then rout that to your welder? The normal way is to put a 125 amp breaker in
your house panel (if you have room, good luck!) and then pull the no. 4 wires
out of your house panel and rout them to your garage. At that point you could
install a subpanel, or you could just run the wire right to your welder plug.
Most guys need more power to a home garage anyway, so this is a good upgrade.
Your electrician might be right, though, you may not be able to pull another 125
amps from your existing panel. Go look at it. Most US panels are completely
full. Not only that, but I don't even know if you can buy a 125 amp single phase
breaker. That's a huge circuit.
Here's what I wound up doing. I bought a house intending to upgrade the power in
the downstairs 2-car garage which I intended to devote to being a shop. Its
panel was completely stuffed. I upgraded my home from a 200A service to a 400A
service which involved buying a new 400A meter base with 2 200A disconnects and
the adapter to connect it to overhead power. That part was about $800. Then I
paid an electrician to remove my existing meter base and route half the 400A to
my existing 200A panel, then to run wire under my house down to the shop to
another 200A panel. After that, when we built on an addition which doubled my
shop space, I pulled 60 amps from the shop 200A to a subpanel in my new shop.
Total cost about $5000 US including permitting. You may have to really scratch
your head to get a Syncrowave 350 hooked up in your garage. Hopefully you
considered all this before you bought it, right?
GWE
coino...@comcast.net
Dec 13, 2006, 10:57:25 AM12/13/06
to
Actually I didn't! I bought the Syncrowave at a great price-so at
worst I'll sell it. The way you stated, for hook up, I'm sure is
best-but that price is more than I can handle. I would think the power
company would want to know the purpose for a 400 amp service also. Not
that it matters. I want it safe but I'll skip it if I have to. I know
a guy that has a mobile welding business. He also does some welding in
his garage. he has the same machine hooked up on a 100 amp breaker and
has had no problem. Since TIG machines have at the most a 60% duty
cycle, that high draw is not constant. also it looks to me like these
machines use less power when welding than on start up.
worst I'll sell it. The way you stated, for hook up, I'm sure is
best-but that price is more than I can handle. I would think the power
company would want to know the purpose for a 400 amp service also. Not
that it matters. I want it safe but I'll skip it if I have to. I know
a guy that has a mobile welding business. He also does some welding in
his garage. he has the same machine hooked up on a 100 amp breaker and
has had no problem. Since TIG machines have at the most a 60% duty
cycle, that high draw is not constant. also it looks to me like these
machines use less power when welding than on start up.
Robert Ball
Dec 14, 2006, 9:18:39 PM12/14/06
to
The most direct is as stated: install 100 or 125A breaker in your
existing panel, run #4 to a welder outlet in the garage. If you want to
hard wire it since it's hard to find a 100A outlet until you get to the
$80 industrial units, you would need a disconnect switch within sight of
the welder. Most electric panels have one or two spare positions in
them. You need two together for a double pole breaker so you may have
to move things around a bit, remove the "knock-out" cover over the spare
breaker positions. All of this is done with the panel open, a job for
an electrician unless you or a qualified friend know what you are doing,
and have turned off the main breaker and VERIFIED THE PANEL IS DEAD. I
burned the tip of a meter probe once while checking that a circuit was
dead; I was very glad it was the meter probe and not my hand. I was
scared almost shitless when a colleague shorted two 200A legs at 380V
(not a typo) together because he assumed the circuit was dead after
opening the breaker. I had to finish the job, he was in shock for the
rest of the day, pun intended. Fortunately it was his screwdriver and
not his hand that got vaporized. It's your house, you decide if
everything else must be stopped for you to make a weld at 400A. A 200A
weld will draw a lot less, you should have no problem. The subpanel is
a good idea if you need additional circuits and can afford the extra
cost but not necessary if what you have is adequate except for the
welder. Talk to your city building inspection department as to what you
can do as the owner, you have more leeway as the owner than a contractor
does, but electrical work is limited due to the potential hazard, it's
in a different league from screwing up adding a hose bibb to the side of
the house and the worst that happens is you flood your yard.
existing panel, run #4 to a welder outlet in the garage. If you want to
hard wire it since it's hard to find a 100A outlet until you get to the
$80 industrial units, you would need a disconnect switch within sight of
the welder. Most electric panels have one or two spare positions in
them. You need two together for a double pole breaker so you may have
to move things around a bit, remove the "knock-out" cover over the spare
breaker positions. All of this is done with the panel open, a job for
an electrician unless you or a qualified friend know what you are doing,
and have turned off the main breaker and VERIFIED THE PANEL IS DEAD. I
burned the tip of a meter probe once while checking that a circuit was
dead; I was very glad it was the meter probe and not my hand. I was
scared almost shitless when a colleague shorted two 200A legs at 380V
(not a typo) together because he assumed the circuit was dead after
opening the breaker. I had to finish the job, he was in shock for the
rest of the day, pun intended. Fortunately it was his screwdriver and
not his hand that got vaporized. It's your house, you decide if
everything else must be stopped for you to make a weld at 400A. A 200A
weld will draw a lot less, you should have no problem. The subpanel is
a good idea if you need additional circuits and can afford the extra
cost but not necessary if what you have is adequate except for the
welder. Talk to your city building inspection department as to what you
can do as the owner, you have more leeway as the owner than a contractor
does, but electrical work is limited due to the potential hazard, it's
in a different league from screwing up adding a hose bibb to the side of
the house and the worst that happens is you flood your yard.
Terry
Dec 14, 2006, 10:13:03 PM12/14/06
to
Several years ago I bought a used Lincoln Squarewave 350 and installed it
in my garage. I hard wired it to the house panel, which is in the
garage, and used a 100 amp breaker. I've never had a problem popping any
breakers or the box, and I've done some welding at 300 amps. The reason
is probably because the welding is for such a short time.
in my garage. I hard wired it to the house panel, which is in the
garage, and used a 100 amp breaker. I've never had a problem popping any
breakers or the box, and I've done some welding at 300 amps. The reason
is probably because the welding is for such a short time.
Terry
[snip]
coino...@comcast.net
Dec 15, 2006, 7:23:40 AM12/15/06
to
Thanks for the help! Matt
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