Hi everyone, appreciate any help on this in advance.

I have a 2006 Fenceman electric fence energiser which I'm trying to repair. I believe the SCR is faulty as it gives continuity across all combinations of terminals. The markings on it are not very clear so excuse the picture, but I think it says either C48C40U or G48C40U. I cannot find this online, can anyone recommend a suitable replacement or how I find out the specs by measuring the board?

The only other broken thing I've found is one of the two 47k ohnm resistors on the HV side gives no resistance reading, so will need to replace that.

I've confirmed the main capacitors and diodes near them are ok. The transformer gives continuity on each side with low resistance readings too, so assuming its ok.

First thing I wanted to try was to replace the SCR. If someone could help identify a replacement it would be much appreciated.

Best regards

 

Welcome to AAC.

International Rectifier's IRG4BC40U is a 600v 20A IGBT not a SCR. Its showing as obsolete and not currently available at the usual primary sources though you maybe able to find it somewhere, eg eBay, around 10-12USD

A possible alternative is ST's STGP30H60DFB

 

Thanks very much Irving, exactly the info I was hoping for! I'll get one ordered.

Looks like they work in a similar way to an SCR, so assume having continuity across all terminals means its definitely faulty.

 

Thanks very much Irving, exactly the info I was hoping for! I'll get one ordered.

Looks like they work in a similar way to an SCR, so assume having continuity across all terminals means its definitely faulty.

Glad to help.

Definitely!

They look more like a MOSFET with a BJT behind. There should be no continuity from Gate to Collector or Emitter ever, and only between Collector and Emitter when turned on by a voltage between the Gate and Emitter.

 

Right
It's IGBT

 

Just wanted to say that the IGBT was replaced and has fixed the fencer, am very pleased so thanks very much for your help!