I have just decided that.....

[ricicle]

Hager are carp.
Reason 1: The earth leads on the rcbos are too short especially in TP boards.
Reason 2:

Untitled

• ricicle
• 3 Apr 2013
• 1

The apertures are too big for the mcbs so leave a nice gap!

 

[securespark]

Can't speak for TP boards.

As for the gap, I've never seen this before, in all my years!

Silly questions, but:

You sure the rail is correctly installed (and true) and the lid aligned properly?

 

[RF Lighting]

They do two ranges of RCBOs. One for domestic boards, and one for TP boards.

The domestic ones are a bit cheaper, 6kA rated and have shorter tails.

 

[ricicle]

That could be the reason then Rob as I have more mcbs to fit and haven't checked those. I only got sent that one today to get a temporary socket going.

 

[ricicle]

Dual post

 

[securespark]

Thanks, Rob, you reminded me!!

You need the ADB (10kA commercial) range, not the ADN (6kA domestic) range.

 

[studentspark]

Neutral tail is longer on a '3 phase' rcbo plus they have a higher kA rating.

I have wondered in the past if it is acceptable to extend the neutral / earth tail to reach the neutral / earth bar.

The difference between the two seems to be the kA rating, but surely the kA would be left irrelevant by the service fuse.

 

[jamesmcbride]

Neutral tail is longer on a '3 phase' rcbo plus they have a higher kA rating.

I have wondered in the past if it is acceptable to extend the neutral / earth tail to reach the neutral / earth bar.

The difference between the two seems to be the kA rating, but surely the kA would be left irrelevant by the service fuse.

Nothing to do with the service fuse really.

Depends on what the pfc is on the installation

 

[mfarrow]

The service fuse should be able to limit the peak fault current, regardless of PFC/PSCC.

With respect to the RCBO, the older ones with black neutrals were a lot longer. The new ones just fit (I'm talking about 20-way domestic board here) but its a bit tight for my liking and doesn't bode for a very tidy installation.

Again, not sure why but the gap and cover fitment in that photo appears to be all wrong.

 

[ericmark]

As mfarrow says the fuse has what is termed a "let through value" which if below 6kA would all you to use a 6kA MCB what ever the prospective short circuit current is.

 

[Spark123]

Let through value is in A²s, if the withstand value of the downstream device is greater than the let through of the upstream device then it is permissible to use a device of lower short circuit capacity.
Not much use though when the thing doesn't physically fit properly!

 

[17thman]

dont forget the blanks and din rail mounted ones to boot!!