Old NBC welder, new problem

[WorkshopChris]

Noticed this on the other side. Manual says the one on the left is the motor field rectifier, one of the components looks cracked. Could this be the problem?

Its posible, is that the one fed via a fuse F1 on the diagram, wires 65 & 66 ? Especially as you can visually see some damage.
Might be worth removing the fuse if so, while testing the main rectifier.

To test the main welding rectifier you will need to remove the AC connections in marked by the wave symbols.

I would take Jim up on his offer to talk you through some diagnostics. He does this sort of thing every day.

 

[Farmerpalmer]

Will do. I've got to take my Mrs to hospital tomorrow, so will call Jim as soon as I can.

 

[Farmerpalmer]

Jim has kindly given me some tests to do on the machine. He is a great bloke and put it in a way that a numpty like me can understand. Sir, I thank you for your time and patience.

To cap it all my wife had good news from her hospital visit, so a great day all round.

 

[eSCHEn]

Jim has kindly given me some tests to do on the machine. He is a great bloke and put it in a way that a numpty like me can understand. Sir, I thank you for your time and patience.

To cap it all my wife had good news from her hospital visit, so a great day all round.

Top dollar good sir

 

[WorkshopChris]

Jim has kindly given me some tests to do on the machine. He is a great bloke and put it in a way that a numpty like me can understand. Sir, I thank you for your time and patience.

To cap it all my wife had good news from her hospital visit, so a great day all round.

Good news , not sure whereabouts you are but if you get stuck i have to occasionally travel up to towards the sudbury area. If that's any use.

Hope you get sorted out soon and stick around all are a good bunch on this site.

 

[Jim Davey]

Feel free to call me if you need any further help. Thanks for the mention.

 

[Farmerpalmer]

Thanks to Jim I found that one of the diodes near the transformers has a short. With a new diode I hope it will be as good as new.

There's a five week delay from the manufacturer for a replacement though.

 

[Farmerpalmer]

Heads up! Tracked down a replacement Semikron SKR 100/04 diode for not a lot of money. £8.74 is a steal compared with what I've seen! Search the Ashleacomponentsltd eBay shop. I bought two. Shame they don't have the SKN version, otherwise I would replace the lot for that price. Get them before they go!!!

 

[Jim Davey]

Did you get her running in the end?

 

[Farmerpalmer]

Hi Jim!

Waiting for the diodes to arrive. Should be soon!

 

[Farmerpalmer]

Replaced the diode, held my breath and tried a weld. It's sorted! Thanks to the guys on this forum my welder is back in operation again. Really appreciate all the help and advice given. Thanks all!!!

 

[Jim Davey]

I had a similar happy end with a rectifier in this EWM. Good news was, it turns out rectifiers and transformers are covered by a 5 year warranty which I had managed to forget as we don't do many conventional EWM migs.
The yellow thing next to it is a load bank for testing the machine without having to actually weld. Leaves my hands free to check voltages,temperatures etc. While the set gets a good thorough run up.

Retired from the rental fleet and off to a new home soon.

 

[ranchero]

i got one of these great machine. put a eurotorch on it a few years ago. i once bought an original torch and was told it was it was last one they had. i wore it out

 

[Farmerpalmer]

Hi, I wonder if I could pick your collective brains again?

A new problem has occurred. When the torch trigger is pulled when welding, the welding wire glows red hot in the machine and sparks fly as the wire holding reel makes contact with the body. The wire eventually melts. When the trigger is pulled when not welding everything is fine. Is there a short in the torch or the machine? I've had a quick look and can't see anything obvious. I've cleaned the shroud and tip on the gun and checked for loose wires.

Thanks!

 

[Farmerpalmer]

There seems to be continuity between the earth terminal on the torch connector block and the wire feed in on the back of the block. Is this normal? There are two live pins on the connector. These show continuity when the trigger is pulled. I assume this is normal.

 

[fridgefreezer]

Sorry to resurrect an ancient post but whilst googling around for this model I found this thread.

I would really love a copy of the manual / circuit diagram if anyone has one they are willing to scan / copy / let me look at.

Ref the last post, I wonder if the motor was damaged by the failed rectifier as mine was

 

[ranchero]

i know this an old post but just in case it helps some one. ref post 34, mines done this [more than once] remove and clean the earth socket on front of machine