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!


2017 NEC and Related
2017 NEC
Now Available!

Recent Posts
Parking lot pole light swap....
by gfretwell
10/24/16 08:46 PM
International Wire Colour Codes
by Tjia1981
10/23/16 12:08 PM
Son of Sparky
by HotLine1
10/20/16 07:43 PM
Speaking of Plugmold ...
by gfretwell
10/17/16 02:37 PM
Broken battery charger? Check for cobwebs!
by gfretwell
10/17/16 02:30 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 14
HotLine1 7
ghost307 7
renosteinke 6
Potseal 4
Who's Online
0 registered (), 81 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#177816 - 05/12/08 08:52 PM welding near electronics
twh Offline

Registered: 03/11/04
Posts: 895
Loc: Regina, Sask.
I have an installation where three DMX controlled lights failed at the same time, at about the time welding was done near one of the lights. The DMX cable is shielded and the lights are daisy-chained with separate inputs and outputs. I'm guessing the welder was the culprit.

What precautions should be taken when welding near equipment that is so sensitive that its signal cable must be shielded?

Is there a wiring method that will reduce the risk?

#177825 - 05/13/08 06:43 AM Re: welding near electronics [Re: twh]
LarryC Offline

Registered: 07/05/04
Posts: 776
Loc: Winchester, NH, US
You did not state what kind of welding was performed, but I will guess it was TIG. TIG uses a high voltage high frequency signal to initiate the arc. The high voltage leaks out of welding leads and that is probably what did the units in. Keep the welding leads at least 1 foot from the control cables. If the welding leads have to cross the control lines, make the crossing at right angles. Otherwise the usual items, minimize lead length, maximize distance between welding leads and suseptable cables, and if possible, have shielding (magnetic and electrostatic) between the welding leads and the victims.

Best protection would be to unplug the cables from the electronics before welding.


#177831 - 05/13/08 07:30 AM Re: welding near electronics [Re: twh]
n1ist Offline

Registered: 02/13/02
Posts: 176
Loc: Malden MA
Most DMX lights have the input and output connector tied in parallel. Electrically, DMX is just RS485 (5V differential) signalling.


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