building / wiring a distro for gigging with

[numpty with a crowbar]

Hey folks,
being a bit of a mug, I'm building a single phase distribution box to split a 63A outlet down to 32's (for someone else, coz they can't wire a plug - it'll end up being used for a mixture of PA & lighting). The plan is to build it, and then get it tested / inspected - only trouble is that the spark who'll check it is a mate and will take the p1ss forever and a day if I make a schoolboy error - it'd be nice to get it right first time without him shaking his head and generally being patronising.

So - this is what I plan to do - could some kind soul (or souls) possibly let me know if what I plan is suitable.

Ok then -
1) 63Amp 240V inlet. This will run to a 63A main switch (or should I get an 80A switch?)
from the main switch I have 2 options
2a) Run it to a single 63A RCD, and from there to 2 x 32A MCB's - these will run to 2 x 32A fixed outlet spurs
2b) run from the main switch to 2 separate 63A RCD's (the logic behind my thinking being that if a bit of kit on one 32A was faulty, a subsequent trip of the RCD would only take out one side, leaving power unnaffected on the other), with each RDC running to a single 32A MBC, and from there to the 32A outlet spurs

Soooo - any suggestions or pointers?

Cheers folks

 

[JohnD]

It sounds to me like a simple submain, except that it is fed from a plug and socket which I'm not used to.

If you want two 32A RCD protected circuits then you would be better off with two RCBOs and one main switch.

What are the finals feeding? Fixed equipment or sockets? If sockets, 32A sounds like a ring but surely you are not going to wire temporary rings?

 

[numpty with a crowbar]

What are the finals feeding? Fixed equipment or sockets? If sockets, 32A sounds like a ring but surely you are not going to wire temporary rings?

I wasn't plannign on rings - just a stright spur from each of the MCB's out to a fixed 32A blue CEE socket - so there'd be 2 32A blue sockets in total as outputs (users would then plug in other kit from there)

I'd thought about going stright from the main switch to RCBO's but since I already have 1 x 63A RCD already spare (and a 63A main switch as well) -I figure it'd be cheaper for the end user to buy another RCD if necessary and 2 MCB's rather than 2 x 32A RCBO's....

 

[Spark123]

It is sounding OK to me, it might be worth while running it by the people over in the Blue Room who are more familiar with this type of setup, is it advisable having lighting (I'm thinking dimmer packs) and sound power feeds mixed? Also if for use with a genny it might be worth going for double pole MCBs.

 

[Lectrician]

I would use a 63amp DP MCB as the main switch, two RCD's and then two 32amp DP MCB's for the sockets.

Therefore you have a main isolator, and an RCD and MCB for each outlet. I would stay away from RCBO's as these are usually DC-Sense and can operate strangely with generators and certain load types. It also gives you more of an idea if it trips due to an overload or an earth fault.

Use flexible cores, not solid (even stranded solid). You should also furrule the ends of the cable before inserting into terminals. Look for sockets with twin screws on terminals - these boxes will be thrown around and be subject to vibration that can loosen screws.

You need to ensure they get tested and inspected regularly - The terminals do work loose over time. Tempting to use threadlock, but not a good idea!