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View Full Version : need help with what size wire and breaker to run on miller syncrowave 300



ralphiejantz
12-14-2006, 11:44 PM
Quick question Im almost finished with the extension I did on the garage attached to my house
I just had my home service upgraded to 200 amp last week and Im running a 125 amp sub panel into the garage where Im running all the outlets and lights and my welder and drill press and other machinery off of the sub panel
My question is I have a Miller Syncrowave 300 tig welder which is a pretty big machine and its currently setup inside the machine for 230 volts what size breaker should I be running off of the sub panel and what size wire should I be running from that breaker to the outlet where the machine will plug into
I have a 50 amp in there right now but Im thinking that it might need to be bigger and Im not sure what size wire to run to the outlet
from the 200 amp service box to the 125 amp subpanel Im running #4 3&1 wire
heres a page out of the miller service manual but Im not too sure on how to determine what size breaker I should run on it
http://i9.photobucket.com/albums/a93/ralphiejantz/welderoutput.jpg

MoonRise
12-15-2006, 01:16 PM
Wow, I check the manual from the Miller website, and that -is- a pretty big machine. To the tune of 720 pounds big.

Now some not so good news. The rated input draw when running at the rated output of 300A for that welder when running off of 230V power is 120A. Yikes! If you have the Syncrowave300 with PFC, then the rated input draw at 300A output is only 96A. But, and it is a big but, the 300 amp machine is -rated- at 300A output and 60% duty cycle but can crank out 375A at 40% duty cycle. And it's the MAX capabilities of the machine that determine the input requirements.

Per the owners manual, the input power requirements for 230V operation are 225A fuses and 1/0 AWG conductors for the non-PFC model and 1 AWG conductors for the PFC model. The grounding conductor for either 300 amp model running off of 230V is a #6 AWG conductor. All per Table 3-2 on page 16 of the manual.

Further 'gotchas' from the manual. Because the unit can do HF AC, any and ALL wiring within 50 feet of the unit and the working zone is required to be within solid metallic conduit (RMC or material of equivalent shielding efficiency) that is shielded, bonded, and grounded per Section 8 of the manual. Note that BX cable is -NOT- considered satisfactory for RFI shielding. The shielded, grounded, and bonded metallic conduit requirement applies to ALL wiring within 50 feet of the welder and the working zone, including telephone, signal, control, etc wiring. If the Miller shielding requirements are not complied with and an operational waiver is desired, a radio-frequency field strength radiation survey could be conducted by the appropropriate personnel in accordance with Part 18 of the Rules and Regulations of the FCC to certify that operation of the unit complies with the FCC limits. If radio frequency interference occurs even though the shielding requirements are met and radiation values are within legal limits, the user is still required to take whatever steps are needed to "clear the situation" (per the manual).

That machine -really- isn't made or rated or suitable for home use, based on the required input power and the RFI (radio frequency interference) HFI (high field intensity) zone.

Could you physically plug/wire in that machine and weld at home? Yes, sort of. Can you do it in accordance with the input power requirements of the machine, per the manufacturer? Nope. Can you operate the machine inside your attached garage next to your house and still meet the RFI HFI shielding requirements? Not likely, unless your house and garage are a -LOT- bigger than what I think of as typical residential stuff (mansions and estates not included in that typical definition).

Sorry for the 'bad' news. It's all in the manual though.

ralphiejantz
12-15-2006, 01:56 PM
moon thanks for the input I have no intentions of using the machine for anything over 200amps ever I only do exhaust fabrication and roll cages and some other chassis work on cars
do you still think I would be able to use the machine if not I will sell it becuase I didnt pay too much for it and Im sure I can get my money back on it

MoonRise
12-15-2006, 03:40 PM
Like I said above, can you physically use the machine? Sort of. But it's not really a home-use machine. The power and RFI shielding requirements sort of are really tough to meet in a home-use scenario.

Hey, I'm all for "More Power!" But only if you can actually -get- that power. In your home-use set-up with a 125A sub-panel, even if you run ONLY the welder and nothing else at all, you couldn't get the full capabilities of the machine.

If you go with a Syncrowave200, your input power and wiring requirements go to a 60A time-delay fuse (manual says call Miller for circuit breaker applications) and wire it up with #8AWG for power and ground conductors. That still gives you your 200A max output, at a much reduced duty cycle compared to the Syncrowave300 (20% @ 200A versus 100% @ 200A, the Syncrowave200 can do 95A output at 100% duty cycle though), but at least the power requirements for the machine are do-able from your 125A sub-panel.

About that HF 50 foot zone though ... it still applies. Anything metal within that 50 foot work/welder zone is supposed to be grounded (shelving brackets and the metal stock on them, metal desks or benches, water pipes, etc) and all wiring is supposed to be in shielded, grounded, and bonded metallic conduit (or equiv). It's the high-frequency welder output that drives that 50 foot zone and the need to ground anything metal in that zone.

ralphiejantz
12-16-2006, 01:18 AM
Yeah I would definately love to trade this machine for something a bit smaller but I definately have about zero cash to throw down right now

so are you saying any high freq welding machine needs that 50ft zone of safety or just the one I have

Sandy
12-16-2006, 01:48 AM
Aside from pacemakers, I'm gonna guess the 50 ft safety zone is more of an "interference" zone than safety. Perhaps the safety of other sensitive digital equipemnt. Maybe TVs, computors, broadband equipment. Of course number one, it's a release of liability for the manufacture. Basically they are saying these machines can and will cause interference. You do all these things and interference may still exist, yet you, the operator/owner are responsible for any and all mitigation.

These are all excellent recommendations, however parts or all may not always be feasible or obtainable. In an industrial complex or tight quarters, for example, you may not be the owner or in control of all facilities within a fifty foot radius. Perhaps your aerial service drop is fifteen feet outside the window. Should it be sheilded with a drain wire? Probably :). Especially if it is off a common transformer with neighboring feeds gutter tapped together.

Do what you can, the best you can and operate at your own risk. :) I think that is the intended statement.

awright
12-17-2006, 06:13 AM
ralphiejantz, I've been using a Harnishfager 300 amp @ 100% duty cycle (450 amp @ 35% duty cycle)(also 700 pounds) stick/tig machine in my garage in an urban area for several decades with no complaints or problems. My machine is rated for 90 amps input @ 220 volts with a recommended fuse size of 150 amps, but I'm using it on a branch dedicated to the welder (hard wired) with a 90 amp breaker in a panel in the garage fed by a 125 amp breaker in my 200 amp service panel.

I'm not necessarily recommending this setup and don't think it is a particularly good idea, but it's all I thought at the time that I could reasonably provide. I have never been limited by the supply because I never use the machine anywhere near rated welding current. I picked the machine up on government surplus many years ago and like it very much.

All my garage wiring back to the service panel is in EMT. I use the machine randomly and intermittently for hobby work, not continuously for commercial work, and that may have helped avoid complaints. I have never had any feedback from neighbors indicating that they have interference. My nearest neighbor is about 25 feet from my service panel. If they do have interference they may not connect it to me even though they have all seen me welding on occasion because my driveway is about 6 feet long and my welder is right inside the garage door. I try to limit the HF usage to the minimum, but do use it regularly.

All manuals, including mine, make a very strong point about having a solid earth ground close to the welder. God knows I tried to provide one, drilling down about 10 feet through my garage floor next to the welder (the longest drill string I could get into the hole inside my garage). However, I never got through the rock into earth to provide a good ground. That's when I realized why my neighborhood was named, "Rockridge". So my system is grounded back at the service panel perhaps 50 feet conduit run (30 feet as the mole crawls - my garage is set into the hillside). So far, so good. No complaints.

So, I would NOT urge you to get rid of your machine. (On the other hand, I can't in good conscience RECOMMEND my setup to you.) I would definitely recommend that, if you choose to install the machine, you run all wiring in solid metal conduit as recommended in the manual and provide a good earth ground at the machine. You'll love it.

awright

out in the shop
12-17-2006, 08:06 PM
i am not certain here about a syncro 300, but i have a lincoln squarewave 255, that max's out at 315 amps. it ONLY requires a 100a breaker at 230v input. i find it VERY hard to believe that an extra 60a of output power would require an additional 125a of input power, i am thinking that some numbers may have been misread, maybe 225a is at 100% duty cycle. you could run that machine at a residence, providing you have a large enuff main panel, and wire it to local code. ps, my welder is not wired to code, not in metal emt. i weld almost exclusively achf, and have never had anyproblem with interferance, not even through the radio when i weld. maybe im just lucky.
todd

ralphiejantz
12-18-2006, 01:13 PM
thanks for all the replies after hearing some responses and talking to a local miller service tech Im going to run it on a 60 amp breaker I have no intentions at running it more than 180 amps like I said before I only do exhaust work and roll cages and some light chassis work
do any of you guys out there using these big machines have them on a plug and outlet
or are they all hardwired into safety switch type box?
I would really like to be able to put a plug and outlet in because I will be storing the machine on the opposite of the garage where my workbench is where I do most of the welding.
Im kinda limited in space so theres no other place to put the welder away when I want to put a car in for storage so I wanted to be able to unplug it and store it away when its not in use, I made dolley for it so it rolls around without a problem
thanks again for the replys

awright
12-18-2006, 02:56 PM
Try logging onto (http://www.crouse-hinds.com) and navigating to:

PLUGS AND RECEPTACLES > Industrial and Welding Plugs and Receptacles - Nonhazardous > Arktite - Metallic (APJ, AR, APR) .

I didn't check pricing but I think you should have somebody standing by with smelling salts when you do.

Try logging onto industrial/marine/aerospace surplus sites. I've run across many heavy duty industrial connectors up to 60 amps in my hunting and gathering, but never found any above that rating although they are obviously made.

A much cheaper approach would be to have a switch box at your work site with readily accessible cable clamps and just clamp in the power wires of your welder each time you weld. Having the connections in the same box as the switch would prevent your trying to connect the wires to powered terminals unless you are REALLY absent-minded. In fact, you can get switches with interlocks that prevent opening the box with the switch engaged. I do not know about the legality of this arrangement.

awright

weldersales
12-18-2006, 04:52 PM
Count me in on the 300 amp in my garage. Been doing it for 35 years. You can run that machine on 70 amp breaker and sleep fine at night. 60? Probably, although you might kick a breaker now and again - no big deal. Those industrial machines pull large inrush current when you hit the pedal - whether welding or not. It is not unusual to trip a breaker just by hitting foot control several times in rapid succession, even with no arc - that inrush again.
Smelling salts is a very good idea on some of the industrial plugs awright mentioned, although, surprisingly, they can be had surplus or used for prices that will not buckle your knees. PM if you need any sources. weldersales

out in the shop
12-18-2006, 09:03 PM
i know someone will probably dig me on this one, but.....i have my squarewave255(100AMP) running off 4ga wire to a 50a dryer receptical purchased at home depot for about 15 bucks. i can unplug my welder and plug in my plasma. i have never had a problem. again i WILL NEVER run that machine at the 315amp max. i have absolutely no need for that amount of juice those industrial ones are about 60 buckss for the cable end, and 100 plus for the receptical. for me, it was an easy choice. todd

ralphiejantz
12-19-2006, 12:06 PM
I checked into those big amp plug and receptacles they are an absurd amount of money
I actually have a really heavy duty 50 amp plug (thing is huge) with a 50 amp receptacle brand new in the box that they guy from the supply shop threw me as a freebie, he said it would do the job just fine but Im not too sure I want to run a 50 amp plug on a 60 amp breaker
I was also thinking about running a 70 amp breaker to a safety switch and then just undo the wires everytime I want to move the machine

what size wire would be good for a 70 amp breaker

does anyone have a chart that specifies what size wire is good for what size breaker thanks for all the help guys I really appreciate it

Roy Hodges
12-19-2006, 12:47 PM
At home despot (home DEPOT) they have a chart on the WALL ,by the wire , that lists what size wire carrys how many amps , according to the national Code . I would guess other stores have that also. And, you can buy an electrical booklet for about 6-8 dollars ,that has all that info you might need

Roy Hodges
12-19-2006, 12:53 PM
P S ; i first had my miller Dial-arc hf (250 amp machine) on only a70 amp breaker , it blew all the time especially when i turned off the machine . I finally wired it direct to the breaker box(only about 5 feet) with a 100 amp breaker
- no more troubles , ever . I did use wire made for 100 amps. Miller specified it to need 95 amps........It uses 240 volts (measured)

ralphiejantz
12-21-2006, 11:18 PM
Alright well Ive finally came up with a decision forget the 50 amp breaker
Im wanting to run a 90 amp breaker and I will hardwire the welder into a safety switch on the wall
what size wire should I be using to run from the 90 amp breaker to the safety switch?
does anyone see any problems with using this setup??
Ive been searching online for a diagram on what size wire to run with a 90 amp breaker but I cant come up with anything
Ive only come across charts that show up to 50 amps
same with the chart at home depot

Aceman
12-22-2006, 02:58 AM
from the 200 amp service box to the 125 amp subpanel Im running #4 3&1 wire

:nono:

Your 125 amp subpanel should have #2 copper or 1/0 aluminum feeding it. If it is indeed #4 copper it should only be a 90 amp subpanel. Coincidentally, this is the same size wire required for your welder. The grounding conductor for your welder is #8 copper.

ralphiejantz
12-23-2006, 01:24 AM
:nono:

Your 125 amp subpanel should have #2 copper or 1/0 aluminum feeding it. If it is indeed #4 copper it should only be a 90 amp subpanel. Coincidentally, this is the same size wire required for your welder. The grounding conductor for your welder is #8 copper.
Yeah thats what ive heard from a few people over the internet
but the electrician that did the upgrade to 200 amp saide #4 copper for the subpanel and so did the supply house and so did about 10 other places that I called and double checked before I bought it and installed it
I only ran a 100 amp breaker off the main box to the sub panel, but the sub panel itself is rated to 125 amps but Im only running 100 to it

also I pretty much finished up the welder today just one more quick question
I ran a 100 amp breaker off of the sub panel and into a 100 amp non fused safety disconnect switch (box) then Im going to hard wire the welder into that, the wire that comes off of the welder is #6 so I should have plenty on there and I dont think I'll be blowing breakers with this setp

My question is inside the safety switch box there are 3 connections on top and 3 on the bottom
my welder has a green wire which comes from a ground and a white and black wire which comes off of the power from the welder

Now the #4 wire that I ran into the safety switch has red, white, black, and the copper wire

The way Im thinking to run it is
Black from sub panel to black from welder (on the first lug)
White from Sub Panel to Green from welder (on the second lug)
Red from Sub Panel to White from welder (on the third lug)
Then run the copper from the #4 wire grounded to the safety switch box itself
Or should it be run a different way??
any help is appreciated thanks

gregben
12-23-2006, 05:12 AM
I don't believe your wiring is correct.
I think it should be:

subpanel welder
--------- -------
black black
red white
copper green

The white wire in the subpanel should not be
connected to the welder at all.

Here's why:
the subpanel is providing a 120/240 volt service
with two hot leads, (red,black) and a neutral (white).
The copper wire is a ground lead for safety.
If you measure the voltage across the black and
red wires you should get a reading of 220-240V.
If you measure from black to white and red to white
you should get 110-120V. The welder has three wires,
two for 220-240V (white, black) and the protective
ground (green). The neutral (white) wire from the
subpanel is not needed/used by the welder.
The green wire from the welder should be
bonded to the bare copper wire in the subpanel, and they
both should be attached to the metal housing of the
subpanel so that there is always a ground connection
from the welder back to the subpanel and on back to
a cold water pipe or ground rod. You don't want to
run your ground wire through a switch/breaker/disconnect.

ralphiejantz
12-23-2006, 12:39 PM
I don't believe your wiring is correct.
I think it should be:

subpanel welder
--------- -------
black black
red white
copper green

The white wire in the subpanel should not be
connected to the welder at all.

Here's why:
the subpanel is providing a 120/240 volt service
with two hot leads, (red,black) and a neutral (white).
The copper wire is a ground lead for safety.
If you measure the voltage across the black and
red wires you should get a reading of 220-240V.
If you measure from black to white and red to white
you should get 110-120V. The welder has three wires,
two for 220-240V (white, black) and the protective
ground (green). The neutral (white) wire from the
subpanel is not needed/used by the welder.
The green wire from the welder should be
bonded to the bare copper wire in the subpanel, and they
both should be attached to the metal housing of the
subpanel so that there is always a ground connection
from the welder back to the subpanel and on back to
a cold water pipe or ground rod. You don't want to
run your ground wire through a switch/breaker/disconnect.
Yeah now that Ive read your response I see where my mistake was
So basically Im only using 2 out of the 3 poles on the safety switch then the white wire from the sub panel is going to go to nothing (just tape off the end)
and the green from the welder (ground) and the copper will get tied together and grounded to the actual saftey switch box itself not a pole on the safety switch
this will leave 1 pole open which should be the proper way because the machine is 1 phase
thanks for the response I really appreciate it

Sandy
12-23-2006, 01:11 PM
Ditto what gregben explained. No neutral this time.


That three pole switch must have cost a penny or two.

ralphiejantz
12-23-2006, 04:02 PM
Ditto what gregben explained. No neutral this time.


That three pole switch must have cost a penny or two.
It wasnt too bad it was like $90 or so
would it be alright to leave the white from the sub panel on the middle post but nothing from the welder contacting the other post
Im not to sure how I feel about just leaving a wire inside the box by itself loose

Sandy
12-23-2006, 04:14 PM
It wasnt too bad it was like $90 or so
would it be alright to leave the white from the sub panel on the middle post but nothing from the welder contacting the other post
Im not to sure how I feel about just leaving a wire inside the box by itself loose

It might be misleading having a wire terminated to a pole going nowhere. You know what is going on, would someone else is the question you have to ask mentally.

"Capped & Stored" or "Taped & Stored" is sort of universal language in visual way. Open up any electrical or electronics and see a wire on a lug or post with nothing coming off of it indicates this is available for use under certain conditions. See a wire capped off and/or bent back means educate yourself before proceeding, using or touching.

No big deal as you are the owner operator in this case.

ralphiejantz
12-23-2006, 05:14 PM
thanks to everyone that responded to this thread you have all been very very helpful, Im hoping to have it finished off tonight and maybe get some work started thanks again for all the help

goodfellow
12-24-2006, 02:30 PM
P S ; i first had my miller Dial-arc hf (250 amp machine) on only a70 amp breaker , it blew all the time especially when i turned off the machine . I finally wired it direct to the breaker box(only about 5 feet) with a 100 amp breaker
- no more troubles , ever . I did use wire made for 100 amps. Miller specified it to need 95 amps........It uses 240 volts (measured)


Yup -- same here. I have the same machine. A 1979 Dialarc HF-P. The power factor correction helps a bit, but for heavy aluminum TIG welding at 200+ amps, my 70 AMP tripped as well. I upgraded to a direct hookup into the 100 amp sub-panel and have not had a problem since.

I found a 15 ft. three wire OO AWG cable on ebay -- that's directly hooked into the subpanel to a 100amp breaker and disconnected with a 150 AMP safety switch (another ebay item).

ralphiejantz
12-24-2006, 06:41 PM
got it all worked out today machine welds absolutely awesome Ive never used a tig machine this big before and man does it beat the econotig and the other small machines absolutely awesome welder
did some aluminum as well today on high freq and didnt see any interference problems with the tv radio or phones I had my wife check while I was doing the aluminum just to make sure