Electric welding machine connection

[mohanlal]

This question is related to one of the "safety concern". Many electrical accidents had taken place without following proper safety standards.
The question could be simple but it is very useful to me

How to connect welding machine and the object to be welded as per standards. I would like be more clear in the earh (Ground) connections. A dedicated earth electrode is essential or plant common earth could be used??
Subramanian

 

[waross]

I will assume that the plant is grounded according to codes.
I will assume that the welding machine is approved and in good repair.
The output of the welding machine is an isolated circuit. Connect the welding ground cable from the welding machine to the work to be welded.
Although the work connection from a welding machine is referreed to as ground, it is not nor is it related to code grounds, or building groungs. Also, the hot terminal is connected to the work for reverse polarity welding.
On machinery, it is good practice to avoid passing welding current through bearings.
No action required, just connect the workpiece to one welding lead and the welding electrode to the other welding lead.
The frame of the welding machine is required to be grounded to the supply system as per code, but this is not related to the connection to the piece to be welded.

 

[dbaird]

This may be of some help to you:

http://www.aws.org/technical/facts/Z49.1-1999-all.pdf

David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.