merlin MCCB service/test

[Paul Maughan]

Hi I have a client with a 1000a merlin mccb as their incoming PD from their private transformer.
Previous maintenance spark has claimed its faulty and trips under no load, so they’re leaving the compressors running 24/7, I find this odd but don’t want to mess around too much as if something goes wrong it’ll shut down the entire site (100+ employees)
I have contacted Schneider as they were happy to pay to just replace it as it’s running an entire factory site. There is no direct fit replacement available anymore.
The site actual bought a used one as a back up, anyway is there anywhere that could bench test/service tgis 1000a mccb to ensure it’s working correctly to then swap them Over ?
Thanks Paul

 

[westward10]

How did they know it tripped under no load.

 

[freddo]

Assuming it's a Merlin ACB one of the sites we are on had one of the transformers 800A breakers keep tripping when no where near it's rated current. Had to get a specialist in to modify the transformers busbars so both the 800A ACBs could be replaced with new, current production models.

You would probably have to send it to Schneider to get it tested.

 

[Paul Maughan]

This is just what I’ve been told by the maintenance manager. I could turn it off and see for my self but I’m being very cautious as to what I do here

 

[freddo]

I wouldn't turn it off, you may never get it back on again.

 

[Paul Maughan]

Assuming it's a Merlin ACB one of the sites we are on had one of the transformers 800A breakers keep tripping when no where near it's rated current. Had to get a specialist in to modify the transformers busbars so both the 800A ACBs could be replaced with new, current production models.

You would probably have to send it to Schneider to get it tested.

 

[Paul Maughan]

That’s one of the options is getting the busbars altered to fit, it’s either this or get the old spare one fully tested/serviced etc

 

[Paul Maughan]

I wouldn't turn it off, you may never get it back on again.

Aye that’s why I’m being cautious and going for a replacement one way or another

 

[freddo]

I'd go down the route of fitting a brand new product, and get the busbars altered during a planned shutdown. At least then you won't be in this position next year when the elderly replacement is also failing. Having a mechanical or electrical failure of a breaker when you are switching it with such high fault currents available is just not worth the risk.

 

[Paul Maughan]

I'd go down the route of fitting a brand new product, and get the busbars altered during a planned shutdown. At least then you won't be in this position next year when the elderly replacement is also failing. Having a mechanical or electrical failure of a breaker when you are switching it with such high fault currents available is just not worth the risk.

That’s a fair point,
I just need to find somewhere that can manufacture the new busbars now !

 

[freddo]

We used Simply Switchgear but we are at the other end of the country to you!

 

[Paul Maughan]

We used Simply Switchgear but we are at the other end of the country to you!

Aye a bit of a drive ! There’s a local switchgear place up here so I’ll try those