Dist Board change

[efiste2]

Is mounting a new dist board on its back allowed these days, as per pic below (apologies for my disgraceful phone camera) I have been asked to change it for an RCD/MCB split board by a mate, Ideally id like to just swap it over in the same position, but ive got a feeling you more experienced and more importantly, more QUALIFIED chaps will know better than i do. ALready spotted the M/C cutout which i will get the DNO to change and whilst there at it Ill be getting them to install an Isolator.

 

[ericmark]

I have a feeling I was looking at a manufactures web site within last few days where it was stating de-rated figures for when mounted other than in normal position. I was directed there by a post on IET forum but can't remember which one.

 

[bernardgreen]

The mechanisms of some MCBs and RCDs are affected by gravity and their operating parameters may be different if not mounted in the normal way.

 

[Steve]

The mechanisms of some MCBs and RCDs are affected by gravity and their operating parameters may be different if not mounted in the normal way.

I find this hard to believe.

RCD plugs are used in all sorts of rotations, they still trip.

RCDs and MCBs are mounted in two orientations in normal use, in vertical and horizontal planes. I dont see how their operation would be affected by having them mounted on their back, to be quite honest.

Think about "tripping" an MCB off, its very easy. I dont see how that mechanic would ever rely on gravity, there feels like theres a big spring in there to separate the poles asap.

 

[securespark]

I had a similar find at a customer's property in Staffs a couple of years ago.

Aside from the fact that the CU was under the bathroom floor, directly below the bath waste, it had been mounted in a non-standard position (i can't remember exactly how).

So I rang Electrium (Crabtree Starbreaker board) and he said that due to the position, as heat rises, instead of dissipating away from the equipment, any heat produced would not so easily be able to escape thus affecting the RCD. He also said that you must not fit boards on end as any heat built up by MCB's will rise into adjacent breakers and possibly cause healthy breakers to trip.

 

[bernardgreen]

I dont see how that mechanic would ever rely on gravity, there feels like theres a big spring in there to separate the poles asap.

I didn't say it relied on gravity...only that gravity might affect the operation if it was in the wrong direction.

 

[sparkyspike]

Is that CU on the floor or on a shelf?

 

[securespark]

Looks like the floor.

TBH, I would bite the bullet and have done with it - either extend the cables and make the cabinet bigger, or fit the CU outside the cabinet.

 

[Spark123]

So I rang Electrium (Crabtree Starbreaker board) .... He also said that you must not fit boards on end as any heat built up by MCB's will rise into adjacent breakers and possibly cause healthy breakers to trip.

Makes me wonder how the breakers survive in a 3 phase board tho

 

[efiste2]

The board is mounted in a cupboard about six inches above floor level, and sinks into the wall. If the only problem is nuisance tripping may occur, and there is no regulations against it, due to the minimal space in the cupboard and the installation of a new cutout and isolation switch, i think ill opt for the direct swap.................Thanks for the advice fella's its most appreciated!!!

 

[securespark]

So I rang Electrium (Crabtree Starbreaker board) .... He also said that you must not fit boards on end as any heat built up by MCB's will rise into adjacent breakers and possibly cause healthy breakers to trip.

Makes me wonder how the breakers survive in a 3 phase board tho

I did think of that at the time, but he was adamant....

 

[ColJack]

The mechanisms of some MCBs and RCDs are affected by gravity and their operating parameters may be different if not mounted in the normal way.

and what about in 3phase boards where they are mounted sideways?

 

[bernardgreen]

They will probably work OK.

One RCB I took apart had a trigger mechanism that was pulled horizontally towards the front of the module by the coil when the un-balance occured. If the unit was laying on its back then the coil would also have lift the weight of the trigger against gravity needing a bit more energy and thus a bit more un-balance before it operated.

If the trigger had been pulled to the rear of the unit then laying it on its back would have made it more senstive.

In the last RCB I opened up the trigger moved sideways so laying that one on its front or back would have had little affect but laying on its side would have.

The RCBs were NOT used again for safety critical purposes.