ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
UL 508A SPACING
by ale348 - 03/29/24 01:09 AM
Increasing demand factors in residential
by tortuga - 03/28/24 05:57 PM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (ale348), 302 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#96334 11/19/05 10:44 AM
Joined: Aug 2001
Posts: 545
A
aldav53 Offline OP
Member
I installed a welding circuit with a 60a breaker in the lower part of a split buss residential panel and put a 70a breaker (max size according to the panel specs) feeding the lower part of a the split buss.
The the welder draws 92 amps max. I didn't want to go over the 70a split buss feeder breaker, so I told the customer he probably couldn't run his welder at maximum without possibly tripping the breaker. Everything is installed up to code, but is this a good idea even being legal?

(This is the same panel I mentioned in the General discussion area about the ("no main disconnect".)


The Golden Rule - "The man with the gold makes the rule"
Stay up to Code with the Latest NEC:


>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides
 

#96335 11/19/05 11:40 AM
Joined: Jan 2003
Posts: 4,391
I
Moderator
A lot depends on the duty cycle of the welder. You need to or at least should look at Article 630 which specifically addresses welders.

Welder outlets, the conductors that feed them and the overcurrent protection for them do not follow the 'normal' rules.


Bob Badger
Construction & Maintenance Electrician
Massachusetts
#96336 11/19/05 03:16 PM
Joined: Aug 2001
Posts: 545
A
aldav53 Offline OP
Member
I'll check that.
Its a Miller Tig welder


The Golden Rule - "The man with the gold makes the rule"
#96337 11/19/05 09:29 PM
Joined: Jun 2004
Posts: 1,273
T
Member
93Amps would be extremely heavy current for a MIG welder used at a residence. That is most likely an instantaneous value.

If it is a Miller MIG running at 120Volts then 60A is way overkill. Just what kind of plug does it ship with?

Dig into their spec sheet; visit their web page.


Tesla
#96338 11/19/05 09:48 PM
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
Welders get their own section in the NEC. It's worth looking up.

The nameplate will list a "duty cycle." This bit of info in turd is used to select your breaker and wire size. In theory, one could run #12, on a 100 amp breaker, if the duty cycle was low enough.
DOing so would probably be foolish, though. Replace the welder with another machine, and you're likely to have to re-do the entire circuit.

#96339 11/20/05 11:45 AM
Joined: Dec 2004
Posts: 209
H
Member
Have you considered putting the welder breaker in the upper portion of the split buss panel and moving some smaller load down like maybe the water heater or dryer(double 30)to the lower portion?

#96340 11/21/05 12:24 AM
Joined: Aug 2001
Posts: 545
A
aldav53 Offline OP
Member
Thats a great idea. Sometimes the obvious just flys right by ya. I check the loads on top.
Thanks,


The Golden Rule - "The man with the gold makes the rule"

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5