Yet another welding/wiring thread -with specs!

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Old 12-28-07, 03:29 PM
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Yet another welding/wiring thread -with specs!

New to the forums and have been searching a little and I'm pretty sure I'm on track - just making sure...

I've got a Hobart Stickmate 205 with the following specs...

***************
Net weight: 83 lb.
Dimensions: 18-3/4"H x 12-2/3"W x 17-1/2"D
Rated welding output: 165 amps at 25 VAC, 20% duty cycle, 50/60 Hz
Welding amperage range: 30 - 205
Max. open - circuit voltage: 80
Amps input at rated output 230 V, 50 or 60 Hz: 47.5
***************

I'm going to be putting this on a 200amp panel with plenty of space left and will be using 8/2 wire for a very short run (less than 5ft) my questions are - should I use a 50amp circuit breaker or something smaller like a 40/45 and is the 8/2 adequate or too much?

Thanks in advance...

P.s. - I've worked for a few homebuilders and completely remodeled my old house but I've never wired up 220v so I want to make sure I've got this clear - I'll need 8/2 with ground correct?
 
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Old 12-28-07, 06:35 PM
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Originally Posted by Chili Palmer View Post
- I'll need 8/2 with ground correct?
let's try that again

back in a minute

ok, we are back to where I was.

#12 cu wire and up to a 100 amp breaker

I know, it sounds odd but per NEC 2005 630.11(A) the ampacity of the supply conductors must be at least the rated ampacity times the duty cycle which gives you 21.375 so a #12 is adequate and per NEC 2005 630.12, the OCPD can be up to 200% (or the next standard size) of the nameplate rating so 2 X 47.5=95 which is not a standard size breaker so you can use a 100 amp breaker.
 
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Old 12-29-07, 01:02 AM
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WHOA!

Section 630.11 does permit supply conductors with an ampacity of not less than 21.37 amps (12 AWG) for this welder. And, section 630.12(A) does permit an overcurrent protection device (OCPD) that is not more than 200% of the welder’s primary input current (47.5 amps). This would be limited to a 90 amp breaker for this welder, not a 100 amp (100 amps exceeds 200% of 47.5 amps).

But, section 630.12(B) limits the OCPD to 200% of the supply conductor’s ampacity. For 12 AWG that would be 25 or 30 amps, depending on the type of conductor.

You can use 12 AWG with a 50 or 60 amp breaker (depending on the type of conductor used). Or, you can use a 90 amp breaker with conductors that have an ampacity of not less than 45 amps. For example, 6 AWG type NM or 8 AWG type THHN.
 
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Old 12-29-07, 01:10 AM
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Originally Posted by nap View Post
let's try that again

back in a minute

ok, we are back to where I was.

#12 cu wire and up to a 100 amp breaker

I know, it sounds odd but per NEC 2005 630.11(A) the ampacity of the supply conductors must be at least the rated ampacity times the duty cycle which gives you 21.375 so a #12 is adequate and per NEC 2005 630.12, the OCPD can be up to 200% (or the next standard size) of the nameplate rating so 2 X 47.5=95 which is not a standard size breaker so you can use a 100 amp breaker.
Wow, 12 sounds a little light for a 205 amp welder, maybe I'll go with 10 instead...

Anybody else?

Thanks in advance.


EDIT: Thanks Juhl, I was researching this while you posted :-)

EDIT-EDIT: So what breaker/wire combo would you recommend given the options below?
 
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Old 12-29-07, 01:30 AM
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Article 630 permits smaller supply conductors based on the duty cycle of the welder. A 20% duty cycle (at 165 amp output) means you can only weld for two minutes out of ten. This down time allows the conductors to cool so smaller conductors are considered safe. This does not take performance into account.

Also, while it is generally permitted to use the next standard size breaker, it is not permitted by section 630.12.

Personally, I would use 8 AWG THHN in conduit with a 70 to 90 amp breaker. If you are using type NM cable I would use 8 AWG with a 70 or 80 amp breaker.
 
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Old 12-29-07, 01:39 AM
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Thanks again Juhl.

This will be wired in the wall so I'll be using NM and probably the 70 amp breaker.

Actually, the receptacle I picked up today at lowes states right on the front 50 AMP, should I concern myself with this. It's the kind that goes in a wall box not the kind that mounts to the wall...I'll go grab it and get a part number...hang on...

Ok, I'm back...here's what I have

http://64.239.63.88/catalog/pdf/G%2024.pdf

It's the third one down (last one) in the top section

"Flush Brown 1254*"

I'll be mounting it in an "old work" plastic single gang box with a metal cover plate.
 
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Old 12-29-07, 01:53 AM
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That is the right receptacle.
 
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Old 12-29-07, 02:00 AM
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Originally Posted by Juhl View Post
That is the right receptacle.
Great, thanks for all your help and I'm really glad I'm not the only one on here this late, now when I get up I have all my answers and I can head straight to the hardware store!

G'night...
 
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Old 12-29-07, 07:40 AM
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sorry about that guys. It must have been later than I thought.

thanks for the catch Juhl.

if you notice, that is why my first post was goofy. I guess I read it wrong, then right, then wrong.

sorry
 
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