Thoughts on this install

[Mattrain1390]

Just carrying out an EICR on a farm (!!) with a number of DBs spread in a fashion more similar to a hand grenade then any logical approach.

This one took my interest the most as from the supplying DB (3PN) the installer has run a 3C SWA from two separate C curve 32A 60898 MCBs. Earthing is TT. This runs into an old 17th RCCB board.

Its not a split load board.

They then have one phase running to a 2mod 32A RCBO which supplies an adjacent building and the other phase to an RCCB which supplies the local equipment within that building.

Lots of thoughts on this but just wondering if others views on this, particularly RCCB/RCBO compatibility when reporting findings......

 

[Mattrain1390]

 

[westward10]

Theoretically there is nothing wrong with the supply but that board is a lash up.

 

[PS Electrics]

Not got my Regs book with me right now but shouldn't they have separate neutrals?

Also are they different phases? then is there danger 415v on the cover of this board?

 

[PS Electrics]

Got the book it was Reg 521.7 and in particular 521.8.2 But it does specifically say each final circuit and this isn't a final circuit. So by the looks of it though certainly non standard not against regs.

Certainly would like to see warning notices that the board is fed from two different supplies.

 

[westward10]

The board has one three phase supply.

 

[PS Electrics]

The board has one three phase supply.

Are you sure? That is not what was inferred from the description? Have I got that wrong?

Supply Board is 3 Phase and there is a 3 core from 2 MCBs. I am taking that is 2 Phase plus Neutral?

 

[westward10]

You are correct it is two phases but they are both isolated by the triple pole switch.

 

[Mattrain1390]

The board has one three phase supply.

No as above it's two phases and a neutral on a 3C supply.
The triple pole 60947-3 isolator has been used to disconnect neutral as well as the two phases.

Yes having got the books out I can't see it's actually contrary to any regs. As you state as it's a distribution circuit the separate neutral as per 521.8.2 doesn't preclude this.

Warning notices re 415v (as not immediately obvious) and isolating at two separate sources seems very sensible. Also although no thermal deg, Im conscious the crabtree isn't type tested for that board, although strangely the Eaton RCBO seems an even worse fit (in an Eaton board) either way it's definitely not ipx2 on the vertical face.

 

[westward10]

The whole thing is home made.

 

[PS Electrics]

I am worried by that Crabtree RCCB it doesn't look like it fits well!

No as above it's two phases and a neutral on a 3C supply.
The triple pole 60947-3 isolator has been used to disconnect neutral as well as the two phases.

Yes having got the books out I can't see it's actually contrary to any regs. As you state as it's a distribution circuit the separate neutral as per 521.8.2 doesn't preclude this.

Warning notices re 415v (as not immediately obvious) and isolating at two separate sources seems very sensible. Also although no thermal deg, Im conscious the crabtree isn't type tested for that board, although strangely the Eaton RCBO seems an even worse fit (in an Eaton board) either way it's definitely not ipx2 on the vertical face.

Yes Crabtree RCCB is of concern it doesn't look a great fit.

Agree with Westward homebrew to save money probably.

Not familiar with poly phase supplies but would check it is definitely poly phase because the breakers are separate (wouldn't just trust the cable colours) since neutral size would be unaffected if true poly phase.

Actually thinking this really ought to be fed from a TP breaker for safety?