110v supply issue?

[Steve46]

just a quick question I’ve searched online but want to be sure before deciding what to do.

I am putting in a supply for x5 110v commando sockets in a workshop.

The commando sockets each have a internal 16amp double pole MCB inside the socket.

I’ve wired from the DB a 32amp 10mm2 supply to a centre tapped transformer as per drawing.

From here I was unsure how to wire out to the x5 commandos.

So I ran a cable from the transformer in to a small 6 way DB and and fed the commando sockets from there the issue I have is that I’ve used x5 16amp single pole MCBs, then thought that they might need to be double pole MCB’s.

Would I need to change the small Db for a larger one and feed the commandos with x5 double pole MCBs?

thank you for your time and have a great day ??

 

[telectrix]

they should be d/p MCBs , IMO, as you have 2 "live" legs, each 55V relative to earth.

 

[Lucien Nunes]

If the transformer centre-tap is earthed then yes, all switching and protective devices must be double-pole, as both the other wires are lines and need protecting against faults to earth and both must be switched otherwise the appliance remains live.

 

[Mike Johnson]

The commando sockets each have a internal 16amp double pole MCB inside the socket.

Now that has confused me? why do you need more?

 

[Strima]

Why not run it as an RFC and try and get the legs the same length the balance the load?

 

[Steve46]

The sockets come with built in double pole mcbs, the problem I had is they are all fed from 1 transformer so I have 5 cables at the transformer that’s why I was planning to put a small db in next to the transformer?
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Cheers for the replies ??

 

[Mike Johnson]

Would one of these do: Legrand EN 60947-1 048-84 Modular Distribution Block 100A-40 Ui 500V ipk 20ka | eBay - https://www.ebay.co.uk/itm/Legrand-EN-60947-1-048-84-Modular-Distribution-Block-100A-40-Ui-500V-ipk-20ka-/302637580524
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You will probably need Bootlace ferrules and a crimping tool if you don't have them already, you can get the Legrand distribution box in the UK.

 

[davesparks]

What rating is the output of the transformer and does it have any output protection built in?
Have you considered a single radial circuit from the output of the transformer?

If not yes the DB will need DP MCB's. Most of the bigger brands of DB have the facility to fit distributed neutral and DP MCB's.
Personally I prefer the schneider Acti 9 range for this.
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Would one of these do: Legrand EN 60947-1 048-84 Modular Distribution Block 100A-40 Ui 500V ipk 20ka | eBay - https://www.ebay.co.uk/itm/Legrand-EN-60947-1-048-84-Modular-Distribution-Block-100A-40-Ui-500V-ipk-20ka-/302637580524
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You will probably need Bootlace ferrules and a crimping tool if you don't have them already, you can get the Legrand distribution box in the UK.

No, it won't do, the OP needs a DB with a neutral kit and DP MCB's.

 

[Mike Johnson]

He's already got double pole MCB's in the socket, why does he need additional double pole MCB's in a DB? I suppose it all accords how long and vulnerable the lead are.

 

[pc1966]

He's already got double pole MCB's in the socket, why does he need additional double pole MCB's in a DB? I suppose it all accords how long and vulnerable the lead are.

He said it is a workshop, so I guess the cable will be fixed and (hopefully) well protected physically, not like trailing leads on building sites that the folk just drive over!