Old Merlin TPN Board

[cartooncat]

Hi,
not strictly (at all) DIY, but I wonder if any of the Sparks on here know the answer?
I have an install with a couple of old Melin TPN boards - The ones before Isobar was used, C45 range if Memory serves (estimate mid 1980's).
These are currently fitted with 100mA 4P RCD incomers. I need to change these incomers for 100A 4 pole switches. Does anyone know if the new C60 100A switch incomers will fit these older boards, or alternatively if the C45 ones are still available anywhere?

Thanks,
Tim

 

[RF Lighting]

Is it the old multi9 style incommer?

Does it look a bit like this?

 

[cartooncat]

looks a lot like that......

Untitled

• cartooncat
• 2 Jun 2013
• 1

not completely sure the image has linked correctly.

 

[RF Lighting]

I'm not 100% sure, but I think the new style schneider MGI1253N isolator should be a direct replacement for that.

 

[333rocky333]

is it an illusion or are the 3 terminals not spaced evenly on the rcd

 

[mfarrow]

is it an illusion or are the 3 terminals not spaced evenly on the rcd

It's an illusion. There are 4 terminals not spaced evenly on the RCD.

 

[JohnW2]

I'm not 100% sure, but I think the new style schneider MGI1253N isolator should be a direct replacement for that.

That Schneider one lookes to have equally-spaced terminals, as compared with the slightly odd arrangement in the photo you posted. Will it fit?

Kind Regards, John

 

[RF Lighting]

I'm pretty sure the prongs coming out of the DB are evenly spaced, and the schneider isolator will fit. I'm not sure why the RCD has oddly spaced terminlas.

 

[JohnW2]

I'm pretty sure the prongs coming out of the DB are evenly spaced, and the schneider isolator will fit. I'm not sure why the RCD has oddly spaced terminlas.

Fair enough, but I would have thought that it would be a right old fight (or impossibility) to get that RCD you pictured to fit onto evenly-spaced prongs (without doing some substantial surgery on them)!

Kind Regards, John

 

[RF Lighting]

The holes on the RCD are bigger than the prongs coming out of the board, so it just fits straight on.

 

[JohnW2]

The holes on the RCD are bigger than the prongs coming out of the board, so it just fits straight on.

Fair enough - I have to take your word for that, because it doesn't look from the photo as if that word work, no matter what size the prongs.

Kind Regards, John

 

[RF Lighting]

Pink lines are the size of the terminal openings.

4 red lines are evenly spaced prongs.

Untitled

• RF Lighting
• 3 Jun 2013
• 1

 

[JohnW2]

Pink lines are the size of the terminal openings. 4 red lines are evenly spaced prongs.

Fair enough!

Kind Regards, John

 

[Lectrician]

I know the MCB's fit, so would expect the incomer to be a direct swap too, but am not 100% sure.

I wonder if the new Merlin breakers recently released will be compatible, and how long they will continue with the Multi-9.

Anyone seen the new Gewiss RCD's which will auto re-close after tripping, if the fault has cleared? Also manually trips the mechanism every month WITHOUT loosing power. Seems a step too far IMO, I would not want to see them used in domestics, that's for sure (the auto-reclosing part anyway). I would only want to see them installed on sites which are under the control of maintenance engineers really, something that goes against what they were developed for!

 

[JohnW2]

Anyone seen the new Gewiss RCD's which will auto re-close after tripping, if the fault has cleared? Also manually trips the mechanism every month WITHOUT loosing power. Seems a step too far IMO, I would not want to see them used in domestics, that's for sure (the auto-reclosing part anyway). I would only want to see them installed on sites which are under the control of maintenance engineers really, something that goes against what they were developed for!

I have to say that I've always thought that the whole concept of auto-resetting RCDs is very iffy indeed. It's only too easy to think of situations (like chopping through an extension lead) in which the 'fault' resulting in operation of the RCD would only be very transient, but with the ongoing situation (e.g. the exposed end of a cut cable) being one in which it would be dangerous to re-apply power. As you say, pretty ridiculous in a domestic environment but, I would suggest, not much better (and, as you also say, pretty redundant) on a 'site controlled by maintenance engineers'. What do regs say about such things?

As for 'tripping the mechanism every month without losing power', it obvioulsy could not 'completely' trip the mechanism, so I suspect that this may be of limited value.

Kind Regards, John