The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Calling all Non-US members!! (Non-US only)
by aussie240
Yesterday at 02:39 AM
Photo Upload Tutorial
by DanK
12/06/16 11:35 PM
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 9
Texas_Ranger 8
sparkyinak 7
Trumpy 6
Who's Online
0 registered (), 196 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#76500 - 02/12/01 03:40 PM Welder Woe's
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
There seems to be some sort of phenomenon associated with arc-welders that escapes me.

This week , for the second time this year, i was called to a welder's shop that apparently caused a transformer fire. By this i mean the transformer on the utility pole.

The first time , i dismmissed this as a faulty t-former. This time i'm not so sure.

Both times, the service was small, 100 amp 120/240 residential, both times the welder was a rather large 50A unit. Both times, there appeared to be no other damage to panels, breakers, etc. Nothing tripped either...

I realize i lack any solid numbers here. Has anyone else dealt with this sort of scenario?

Sparky

Top
2014 / 2011 NEC & Related Books and Study Guides
#76501 - 02/13/01 02:05 PM Re: Welder Woe's
Tom Offline
Member

Registered: 01/01/01
Posts: 1069
Loc: Shinnston, WV USA
I'd be willing to bet that this was a cheap "buzz box" type welder. I've run into something similar. It didn't burn out the transformer but it did cause some overheating of the grounded conductor & grounding conductors at the service. The owner of a mobile home was welding some additional steel to the fromae under his mobile home & the welder was plugged into a properly installed 50 amp circuit. He was having a hard time running a bead & as stated, the neutral & grounding conductors were getting hot. The steel was bonded to the equipment ground of the mobile homes panel as required. All I could think of was some sort of bizarre circulating current. I've seen this problem again & it also involved welding to something that was bonded to the electrical service.

I never did come up with an answer.
_________________________
Few things are harder to put up with than the annoyance of a good example.

Top
#76502 - 02/13/01 07:07 PM Re: Welder Woe's
Scott35 Offline

Broom Pusher and
Member

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
This sounds like high harmonic distortion!!

Scott "S.E.T."
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

Top
#76503 - 03/18/01 12:23 AM Re: Welder Woe's
old Appy Offline
Member

Registered: 03/18/01
Posts: 120
Loc: Auckland, New Zealand
By this i mean the transformer on the utility pole.

Wouldn't correct discrimination at the fuse board cause the board fuse to blow? rather than the Pole

Top
#76504 - 03/18/01 04:02 AM Re: Welder Woe's
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Hi Appy!
how are things in New Zealand?

as for this thread, the suspect is the return path's distortion. This is something i endevor to assess my next visit to a welding shop. maybe get my TRMS fluke on it while the welder does one of those "stuck the rod to the work" deals...


Top
#76505 - 03/18/01 08:28 AM Re: Welder Woe's
Bennie R. Palmer Offline
Member

Registered: 11/09/00
Posts: 72
Loc: Milwaukie, OR 97267 USA
Old Appy: This is a pleasure to see your participation in this forum.
I love New Zealand, and the people. I spent some time, in 1980 and 81, in Auckland, Wellington, and Christchurch.
I was a member of the US Antarctic Research Expedition. The staging area was in Christchurch.
I was really impressed by the work ethics, and quality performance by the New Zealand Team at Scott Base. They constructed a camp, using our packing crates, that was superior to our pre-fabricated camp that was shipped in the crates.
Please continue to participate, you should have some good information to share.
Best regards; Bennie

Top
#76506 - 03/18/01 08:45 PM Re: Welder Woe's
Scott35 Offline

Broom Pusher and
Member

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
Bennie.
Welcome back to the group. How's the movie thing going?

Scott SET
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

Top
#76507 - 03/19/01 05:45 AM Re: Welder Woe's
Bennie R. Palmer Offline
Member

Registered: 11/09/00
Posts: 72
Loc: Milwaukie, OR 97267 USA
Scott: Not much progress, its still on the drawing board. I'm not famous yet!

Top
#76508 - 03/19/01 08:17 AM Re: Welder Woe's
Mike Offline
Member

Registered: 02/21/01
Posts: 65
A few years ago, we experienced a severe cold snap. I remember reading a newspaper article about a homeowner using a welder to thaw out the house water pipes. Unfortunately, the house caught on fire. The insulation ignited because of excessive heat on the bonding jumper which was connected to water piping system. The heat was caused by extremely high current from the welder induced on the bonding jumper going back to the neutral in the service panel. The recommendation to avoid such a situation was to disconnect the bonding jumper before thawing out the pipes.

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals