Swapping an MCB on a Contactum board

[Fishingsmurf]

Can anyone tell me how to swap a Contactum MCB? Their web site is down so I can't look there.

Had a problem with the fuseboard this morning, mains tripped out. So I switched off all the MCB's, reset the mains and switched them on one by one. All work okay, except one, which won't reset. Unplugged everything from that circuit, still won't reset, so I switched the mains off again, and even with no supply this one MCB won't stay on. Hopefully I have deduced correctly that the MCB has had its day?

I have a spare MCB of the same size, so I can swap them over. I can't just move the wire from one to the other, not enough reach.

However, I can't work out how to get the MCB disconnected from the fuse board....can anyone help? The bottom screw appears to go through a hole in a copper mounting panel, and the screw won't fully come out so I can lift the MCB off?

Thanks very much,
Paul

 

[fattony]

You could disconnect the cable from the associated mcb and put in connector block then try switching the mcb on, this will prove if the mcb is at fault. Do this with main switch off.

 

[Fishingsmurf]

Done that - with no supply, and no wires connected, the MCB will not stay on.

The bit I'm struggling with is how to remove the MCB from the copper busbar so I can put the spare in its place.

Paul

 

[kai]

With the breaker, you slacken off the lower screw, and often at the back of the breaker, visible underneath it, there is a small din-rail clip. Use a small flatblade screwdriver to unhook the din-rail clip, and the breaker should unhook from the board quite easily - with the power turned off of course.

 

[RF Lighting]

I'm not familiar with that brand of CU, but some CUs require you to undo the bottom screw on all the MCBs and drop the busbar out of the board before you can remove an MCB.

 

[baz1968]

There's a pdf guide for replacing mcb's on the TLC site.

http://www.tlc-direct.co.uk/Technical/DataSheets/Contactum/Cu_Instructions.pdf

 

[Fishingsmurf]

Thanks Baz, downloaded it and will give it a try later today.

Paul