Merlin Gerin neutral bar

[RF Lighting]

There is a neutral bar above the red slidey busbar switches under a plastic cover.

It attatches to neutral just above the main switch and runs the full width of the live busbar.

It does not connect to anything at the other end, and from what I can see it serves no useful purpose.

Does anyone know why it is there? I realise it must be doing something, but I don't know what.

 

[ricicle]

To feed an RCD if the board were to be retro-fitted as split load?

 

[securespark]

It says "NEUTRAL CONNECTION COVER" on it.

I presume it attaches to that neutral terminal bar to the l/h/s of the board.

As to why it's there I'm not sure - I'm not too familiar with MG stuff...

What are the red switches for?

I guess you don't have any instructions?


My best guess is that in some bigger boards, it feeds another neutral terminal block on the r/h/s of the board.

 

[ricicle]

Does it supply Neutrals to the RCBOs?

Secure, the red switches isolate the busbar prongs into the MCBs.

On most of the MG boards I come across they are black.

 

[Adam_151]

possibly for breakers with a switched neutral*, or RCBOs ??


*Hager certainly used to have such a CU in their range, in intended for housing assoc. properties, so in the event of a fault causing RCD to operate, a phone operator could run through a flowchart to have the occupant narrow down the fault and isolate the faulty circuit, and allow the electrician to not have to be dispatched until the next day!

 

[RF Lighting]

AFAIK it is only fitted in SP boards, which do not got upto very big sizes (a TP board with either TP supply or single phasing kit would be used for larger stuff)

The red switches are to turn each individual busbar prong on when an MCB is fitted. This is so there are no direct contact-able live parts even with the covers off

The neutral bar at the left is connected to the top of the main switch, and this extra bar connects to that. It could be removed altogether, and the board would still function normally

 

[jeepmadmike]

it is neutral rail and there are links available so double pole mcbs can be used for phase and neutral.

 

[RF Lighting]

I dont suppose you know how they attatch on do you?

Just because I'm curious

 

[Spark123]

Not very clear but see page 4 here: clicky.
When I get my computer back together I'll scan a better image.

 

[Lectrician]

You can get double pole MCB's (switched neutral), and these connect to that bar.

Very rare to see any attached.

They are two modules wide, with a dogleg up onto the neutral busbar.

Ideal for insulation resistance testing etc.

Quite common on caravan parks.

 

[jeepmadmike]

they are are widely used in industry for 110v CTE socket outlets protection
Also central neutral kits are available for TP+N DB's

 

[kai]

The MCB tabs are a good idea, if you have to isolate a circuit, you could move the red switch tabs to the OFF position, as well as locking the MCB lever off - belt and braces approach.

The MCB tab levers on newer units should really be BROWN, replacing red.

 

[Lectrician]

They are brown And brown black grey.

They must never be swithed on load, and have been known to burn out....costly.