Schneider Vigi units

[i=p/u]

I've Been sent to test a plant room, which has these Vigi units, it's a TT system. I'm having trouble trying to get the breaker and vigi unit to hold and the test button seems to do nothing. After reading another post I'm thinking the wrong gear is used. The neutral from Breaker has been crimped and going to neutral bar and the neutral of circuit goes into Vigo unit with L1, L2,L3.

any help

 

[Lucien Nunes]

More info please... What results do you get from an ordinary RCD test? If you've got an EL clamp, put it round the four load cables to discover the actual leakage. Why do you think they are the wrong units?

 

[i=p/u]

Cause the breakers won't hold on, and the test button is floppy and doing nout. I don't enough about them or eve how they operate or should be wired.

but I read a thread on here and says the neutral should be switched on TT system...

 

[Lucien Nunes]

Yeah but... what are the %$£"£*! readings? If you were in my plant room I'd have wanted the thing running again about 2 hours ago, isolated neutral or no isolated neutral!

 

[D Skelton]

Vigis are used to turn a TP OCPD (60898) into a TP RCBO (61009). The busbar connects into the OCPD as normal then the outgoing terminals are connected through the Vigi leaving the TP+N terminals you can see at the bottom of it. The circuit's neutral is connected to the Vigi as you normally would on any RCBO.

If the Vigi won't hold and the test button doesn't do anything there are three potential problems, either you have an earth fault, a short circuit or a faulty unit. Without further information and having worked with Merlin a lot and never had a problem with it I'd be betting on the first of those three potential problems.

 

[brightspark2010]

If you are only testing was it not fine when you arrived? As mr Skelton says maybe you have opened something creating an earth fault if a conductor was trapped? I am not sure what damage was caused but you cant conduct insulation resistance test through it was a global ir test done?

 

[Sintra]

Hope you didn't IR test it!!

 

[i=p/u]

Nope didn't hold from the off on 2 out of the 3. One holds but test button does nothing.

I tested the cables from Vigi unit to isolator they supplying. I was thinking someone has done IR them or they are connected wrong as the 3 test buttons don't work.

 

[DPG]

Ooooh, come on, admit it - have you killed em? Daz

 

[i=p/u]

I'd admit it, I IR tested supply circuit to this board with main switch off. Then every circuit is less than 2 -3 meters .

Doesnt mean someone else hasnt.

 

[D Skelton]

It is possible if someone has IRd them that they're fried, still, Merlin gear in my experience has always been bomb proof? I'd be stumped if the gear was faulty.

 

[Engineer54]

It is possible if someone has IRd them that they're fried, still, Merlin gear in my experience has always been bomb proof? I'd be stumped if the gear was faulty.

It's not that uncommon Mr D, but i'll go along with you in stating that MG vigi units being one of the first RCD devices ever available and are among the better RCD devices out there. Time proven shall we say!! lol!!

The vast majority of the projects i've ever worked on have all been nigh-on 100% MG/Schneider from MV through LV....

 

[i=p/u]

I wouldn't let you work on selv e54.