Help for Welding Problem

By lianhuaj Date 09-20-2005 19:54

We have a weld cell which has 7 MIG Welding Robots. Without any changes, sometimes all welds made by each robot becomes narrow and thin, short of weld filling metal. It looks like every weld does not get enough welding current. It seems something that has influence on the whole weld cell. Is it possible that incoming power flunctuation causes the problem? If it is, where do we check it?

By Lawrence (*****)

Date 09-20-2005 20:16

Check your work leads first. Poor connections here will cause all kinds of havoc.

By lianhuaj Date 09-21-2005 15:07

Each of 7 welding power sources uses seperate work lead and wire lead. When the problem happens, it happens to every welding power source at the same time. After a while, the problem disappears. It looks strange, isn,t it?

By MDG Custom Weld (***)

Date 09-21-2005 18:28

Look over your shop, what kind of equipment causes a large current draw for a short time. A/C units, large motors, resistance welding equipment, you get the idea. Look to see what other large equipment is on the same buss bar or current loop as your 7 head cell. Last, check that any other systems in the plant have similar problems. How old are the power supplies, most of the newer units have an automatic shut down if incoming voltage drops below a given number.

By - Date 09-21-2005 18:39

I agree.. It sounds like a power surge problem.

By lianhuaj Date 09-21-2005 22:19

Thanks, guys. It is logical to think we have the power surge problem. We will check it.

By billvanderhoof (****)

Date 09-22-2005 06:37

Obtain a recording voltmeter and put it across the line for a while. They used to record on a paper chart, probably now save results in memory for download to your computer.
Bill

By cfrancis (**)

Date 09-29-2005 19:59

We had that problem. On several critical jobs,,we changed to inverters. They can handle HUGE voltage drops and they still deliver exeactly as dialed.