replace double socket with commando socket?

[unclebob1]

Can i do a straight swap between and existing double socket and a commando socket?

The setup i have now is as follows:
RCD protected 32A MCB, for a pantry/gadget room (Has sky box, NAS, and a couple of computers, UPS etc). There are TWO double sockets next to each other from which the UPS and Computers are plugged into, but there will be lots more to add (router, switch/hub, couple of home automation controllers etc), so I'll be looking to get a rack mounted power bar. It comes with a blue (32A) commando connector.

So can i remove one of the two double sockets and put this in its place?

The existing circuit is a 2.5mm ring and serves just this room, (4 other double sockets), which MAY have a tumble dryer and washing machine in the future, and an under counter fridge.

 

[ban-all-sheds]

No, you may not, because:

The existing circuit is a 2.5mm ring

You may only have BS1363 accessories on such a circuit.

I'll be looking to get a rack mounted power bar. It comes with a blue (32A) commando connector.

Remove that plug and put a BS 1363 one on it.

 

[jamesmcbride]

Remove that plug and put a BS 1363 one on it.

Or buy / make an adaptor to convert the 32a plug to a 13a one - the chances are you won't be able to terminate the cable from the PDU in a 13a plug.

Or use a fused spur to supply the 32a socket.

 

[deadshort]

Or use a fused spur to supply the 32a socket.

easy

DS

 

[unclebob1]

Fused Spur would work... Though depending on the load, 13A fuse may not be sufficient. Will spend a bit of time and total up requirements.

Thanks for the suggestions.

 

[AdrianUK]

Fused Spur would work... Though depending on the load, 13A fuse may not be sufficient. Will spend a bit of time and total up requirements.

I hope it will

13A @ 230V = 2.99kW. With leccy at approx. 15p/kWh that would set you back about 45p/hr or £11/day or £330/month or almost £1k on a quarterly bill ..... that's a lot of IT kit!!!

 

[AdrianUK]

Or use a fused spur to supply the 32a socket.

So, raising a point for discussion around the 32A socket on a ring final...... BAS gives a firm NO & jamesmcbride suggests using a FCU... but ... what is the risk with the Ceeform directly on the 2.5mm ring final?

Assuming that the PDU has a flex suitable for at least 32A load (fair assumption or its not 'fit for purpose' on a 32A radial) then it is protected by the OCPD at the origin. The 32A socket & plug, likewise, are protected from overload by the OCPD at the origin ... so where is the issue? (leaving aside the letter of BS7671 stating that only BS1363 accessories can be used).

Is it with the distribution of currents around the 'ring'? I suppose that, it the 32A socket were to be placed 'very close' to the origin then the shorter length of 2.5mm would carry the 'lions share' of the current and potentially overload that length of cable. But one could also place 3 x single 13A sockets next to each other, within a short distance of the origin, and connect a 2kW heater to each. Would this not have a similar effect but still be 'legal'?

 

[EFLImpudence]

(leaving aside the letter of BS7671 stating that only BS1363 accessories can be used).

You cannot do that.

It says that "BS1363 accessories MAY be supplied through a ring final circuit". MAY = are allowed to.
It then states the special dispensations for the ring. Most importantly the reduced csa with a 30/32A opd.

That implies that other things may not be supplied through this type of ring.
Obviously two conductors may form a ring (for other reasons) but the opd should be less than the csa of the conductor.

It would not be prudent, anyway, to have a 32A load at one point of a ring with unlimited sockets around the rest of the ring.
It is obviously fitted with the 32A plug for a reason and should be on a dedicated circuit.



The thread does beg the question of why this 32A device is being purchased if a 13A spur is sufficient for the loading.

 

[unclebob1]

It's not being purchased - it's being recycled, the length of the ring is fairly short, max 20 m total - dedicated ring for the room which is across the hall way from the cu. Looking at the numbers I don't till hit anywhere near 13a, so will see if I can rewire the pdu to work on a single socket, or hardwire it so it becomes part of the ring itself in place of one of the doubles.

 

[EFLImpudence]

Why not buy a 13A one which comes with a normal plug?

 

[unclebob1]

It's not being purchased - it's being recycled.

It's being ripped out as part of a new infastructure build so will end up in bin, I'll be looking to reuse what's there...

 

[EFLImpudence]

Ah, fair enough.

So, if you can't get the wires in a 13A plug, replace the cable as well.

 

[ban-all-sheds]

...or hardwire it so it becomes part of the ring itself in place of one of the doubles.

If you do that make sure that you change the internal wiring - an n-socket spur is also a no-no.

 

[SimonH2]

It would not be prudent, anyway, to have a 32A load at one point of a ring with unlimited sockets around the rest of the ring.

Does it really make that much difference ? After all, there's nothing against having several (double) sockets side by side. What's the difference between (say) a couple of fan heaters (or perhaps a tumble drier and washing machine) plugged into one double socket, vs (say) 20A running off a BS4343 socket ? As long as the BS4343 isn't closer than (from memory) about 20 to 25% of the total ring length to the CU, then it's not possible to overload the shorter leg.

... there will be lots more to add (router, switch/hub, couple of home automation controllers etc), so I'll be looking to get a rack mounted power bar. It comes with a blue (32A) commando connector.

Seriously, you are vastly over-estimating what load you will be pulling. That list is looking like a few tens, or couple of hundred watts. An amp or two.
Add in a few amps for the computers, and you're very very unlikely to hit the limits of a 13A fuse.
You have to remember that "rating plate" loads for IT equipment are notoriously overstated. I've seen something like a 5V 1A plug in power supply (to only 5W output) stated as something silly like "1A max" for the mains input So if you believe these completely fictitious values then you can quickly add up to silly supply requirements.

There's also the practical issue that by the time you do reach 13A, that's 3kW. Try putting a 3kW fan heater in your little room and see what temperature it reaches within an hour or two - you won't want that sort fo power running for long.

 

[EFLImpudence]

Does it really make that much difference ? After all, there's nothing against having several (double) sockets side by side. What's the difference between (say) a couple of fan heaters (or perhaps a tumble drier and washing machine) plugged into one double socket, vs (say) 20A running off a BS4343 socket ? As long as the BS4343 isn't closer than (from memory) about 20 to 25% of the total ring length to the CU, then it's not possible to overload the shorter leg.

It may be no different than the examples you mention, nevertheless what I wrote is correct and should not be done.

It has transpired that it is not going to happen anyway.