Need to get Commando Socket installed but having trouble to find the right guy

[Sam_Hammersmith]

Hello,
I am looking for some advice please. I want to get a commando socket installed in my front garden to plug in an EV car charging device where the amps is adjustable from 9A,10,,16 and 32A. (https://www.amazon.co.uk/EVDANCE-Charger-Waterproof-Electric-Commando-Black/dp/B0D2QDNWR6?th=1)

I want to keep the connection separate from my main household circuit. I inquired with one of the electrician and he saw the pictures and videos of the house. First, he said that not to have a separate unit for the commando socket and then he said that it should be done in the same unit as house. The house unit is old, so he said that the whole thing will need a replacement and it would cost £1700, which is 3 times higher than my budget. I was told to get a commando socket from a dedicated unit. Can anyone possibly put me in the correct direction here ?

 

[UNG]

To my mind electrical interlocking (and I'm probably wrong on this) is controlled by a electrical signal; such as a voltage applied by the connected car or a data exchange, all of which operate a contactor to provide the power.

The the charge is actioned by the proximaty pilot and control pilot pins

To date my experience is limited to using an EV charger has been for supplying a Public Address system. It was an obvious home made cable chopped from a charging lead with appropriate wires taped into 2 bunches to a Ceeform socket and a switch to activate the charger. Initially it didn't work so I buzzed around the pins with a meter and found 240V but as a control voltage rather than power, then repaired the botched cable with no strain relief.

Given that the control voltage is 12v and also uses PWM control I can only assume that you had found a chargepoint that had been modified in some way for there to be a 240v control voltage

 

[sunray]

The the charge is actioned by the proximaty pilot and control pilot pins

Given that the control voltage is 12v and also uses PWM control I can only assume that you had found a chargepoint that had been modified in some way for there to be a 240v control voltage

I have no idea, the first I'd had any dealings with. The problem was simply a wire pulled from the in line switchs terminal.

 

[sunray]

I am aware of the difficulty of using public charge points for other purposes

 

[Simon47]

I would challenge anyone to explain (in terms that stand up to rational interpretation) how a mechanically interlocked Commando socket is less safe that a cheap 13A socket.
Most 13A sockets only need "something" jabbed into the earth pin hole to make live contacts accessible. From memory (it's a long time since I've used one, and I didn't pay much attention to the details), the Commando needs the plug inserted to push in some locking mechanism - and then either a switch or the plug to be rotated. So harder to override the safety function.

And then there's the simple fact that the regs explicitly say a Commando can be used. So are we really to believe that it's "safe" if provisioned for EV charging, but unsafe otherwise ? Does it become unsafe if I plug in a welder, but then become safe again if used for charging ?

Not to mention, the only thing stopping the unshuttered holes in an EV charger becoming live is some electronics, not built to any sort of formal safety case (thinking in terms of ISO 61508 Functional Safety & it's derivatives), not maintained/tested, so generally not something I'd want to trust.

The only thing left to point out is that if you belive "compliant = safe" then I've a bridge for sale you might be interested in.

 

[Brother Blue]

Most 13A sockets only need "something" jabbed into the earth pin hole to make live contacts accessible. From memory (it's a long time since I've used one, and I didn't pay much attention to the details), the Commando needs the plug inserted to push in some locking mechanism - and then either a switch or the plug to be rotated. So harder to override the safety function.

The commando sockets also only need something suitably sized shoved up them to defeat the interlock, it's often a little lever located at the end of the keyway slot.

i've done it many times to get a set of test probes into the socket.

 

[evstruggler]

The commando sockets also only need something suitably sized shoved up them to defeat the interlock, it's often a little lever located at the end of the keyway slot.

i've done it many times to get a set of test probes into the socket.

Is the purpose not just to protect children from accidentally electrocuting themselves - if it had a switch as well then would need to turn the switch on then the equivalent of lock pick the socket. Realms of ludicrous efforts at safety.

 

[Brother Blue]

Is the purpose not just to protect children from accidentally electrocuting themselves

Interlocked commando sockets were not designed with children in mind at all, they were designed to prevent plugs being inserted or removed whilst the socket is live.
This prevents the plug being used to make or break load current which would cause arcing and potential danger. Whilst the smaller sizes are rated for making/breaking load current there are times when you would want/need to prevent this.

 

[evstruggler]

Interlocked commando sockets were not designed with children in mind at all, they were designed to prevent plugs being inserted or removed whilst the socket is live.
This prevents the plug being used to make or break load current which would cause arcing and potential danger. Whilst the smaller sizes are rated for making/breaking load current there are times when you would want/need to prevent this.

Fair enough but this is more to do with the purpose of the regulations. In the old days all you had was MCBs, then came RCDs, surge protection, Pen fault protection. So if someone has an interlocked socket from years gone by connected to a 32a or more MCB and they plug a charger into it nobody is going to stop them as the regs are not retrospective. So the question is does interlocking provide the same or as as good protection against children inserting things into the socket (not carrying out socket surgery). The regulations say you can install interlocked sockets in a non residential setting but do not categorically say you cannot install interlocked sockets in a residential setting which is where the grey comes in. If there is no safety issue and it’s a grey area then I don’t think the electrician could be blamed for fitting it.

 

[Avo Mk8]

The regulations say you can install interlocked sockets in a non residential setting but do not categorically say you cannot install interlocked sockets in a residential setting which is where the grey comes in.

Westwood has previously explained that the Code of Practice for EV charging says that Commando sockets cannot be used in a domestic setting. I don't have a copy and don't understand the legal standing of this CoP vs BS7671.

BS7671 section 533.1.201 says that domestic sockets must be shuttered. Commando sockets are not shuttered but they can be interlocked. BS7671 does not as far as I'm aware recognise any equivalence.

Then BS 7671 Section 722 'Electric Vehicle Charging Installations' says interlocked commando sockets can be used, in fact it specifies they are to be used. So to me it's all a big inconsistency, not so much as a grey area as complete ambiguity!

 

[mainline]

Westwood has previously explained that the Code of Practice for EV charging says that Commando sockets cannot be used in a domestic setting. I don't have a copy and don't understand the legal standing of this CoP vs BS7671.

BS7671 section 533.1.201 says that domestic sockets must be shuttered. Commando sockets are not shuttered but they can be interlocked. BS7671 does not as far as I'm aware recognise any equivalence.

Then BS 7671 Section 722 'Electric Vehicle Charging Installations' says interlocked commando sockets can be used, in fact it specifies they are to be used. So to me it's all a big inconsistency, not so much as a grey area as complete ambiguity!

Also, The ev code of practice is related to 60309-2

No suggestion that 60309-4 shouldn't be used 60309–4 deals with interlocked type ones.

60309-4
Replace Clause 12 of IEC 60309-1:2021 or of IEC 60309-2:2021 by the following:
12 Interlocks, switches, and their components
12.1 Switched socket-outlets with interlocks shall be so constructed that a plug or appliance
inlet cannot be completely withdrawn from the socket-outlet while the contacts of that socket-
outlet are live, and the contacts of the socket-outlet cannot be made live until a plug or
appliance inlet is in proper engagement. The contacts shall not open or close on load.

 

[PS Electrics]

Also, The ev code of practice is related to 60309-2

No suggestion that 60309-4 shouldn't be used 60309–4 deals with interlocked type ones.

60309-4
Replace Clause 12 of IEC 60309-1:2021 or of IEC 60309-2:2021 by the following:
12 Interlocks, switches, and their components
12.1 Switched socket-outlets with interlocks shall be so constructed that a plug or appliance
inlet cannot be completely withdrawn from the socket-outlet while the contacts of that socket-
outlet are live, and the contacts of the socket-outlet cannot be made live until a plug or
appliance inlet is in proper engagement. The contacts shall not open or close on load.

I was going to make that very point. Lots of discussion about this on the IET forums.

The CoP is technically correct in referencing 6309-2 which is the socket on its own and therefore not shuttered. I would argue that when the CoP states that 60309-2 cannot be used it is specifically referring to the socket on its own and therefore not ruling out the use of these sockets provided they have interlocks.

60309-04 is no less safe than a shuttered socket since access to live parts is prevented. Also BS7671 in the EV section says that 60309-2 with interlocks is acceptable for an EV charging solution. (As someone else mentioned)

I would imagine the same principle as to why the sockets on EVCPs are not shuttered due to the fact that they do not become live unless connected. This was pointed out on a thread on the IET forum.

There is also the general view put up on the IET forums that these sockets are not for Household and general use and therefore exempt from the shuttered requirements. IMO this is a little bit more nebulous but still could be argued and probably used when these are installed in Garages and Workshops attached to domestic dwellings.

Interestingly there isn't consensus on this on the IET forums, which fits in with some Electricians happy to install an interlocked 60309-2 socket for EV charging and others that won't!

I have recently seen a 60309-4 install posted on YT by a NICEIC registered electrical company.

 

[mainline]

I was going to make that very point. Lots of discussion about this on the IET forums.

The CoP is technically correct in referencing 6309-2 which is the socket on its own and therefore not shuttered. I would argue that when the CoP states that 60309-2 cannot be used it is specifically referring to the socket on its own and therefore not ruling out the use of these sockets provided they have interlocks.

60309-04 is no less safe than a shuttered socket since access to live parts is prevented. Also BS7671 in the EV section says that 60309-2 with interlocks is acceptable for an EV charging solution. (As someone else mentioned)

I would imagine the same principle as to why the sockets on EVCPs are not shuttered due to the fact that they do not become live unless connected. This was pointed out on a thread on the IET forum.

There is also the general view put up on the IET forums that these sockets are not for Household and general use and therefore exempt from the shuttered requirements. IMO this is a little bit more nebulous but still could be argued and probably used when these are installed in Garages and Workshops attached to domestic dwellings.

Interestingly there isn't consensus on this on the IET forums, which fits in with some Electricians happy to install an interlocked 60309-2 socket for EV charging and others that won't!

I have recently seen a 60309-4 install posted on YT by a NICEIC registered electrical company.

There are lots of new builds that have a 32amp commando socket installed for EV use.

There doesn't seem to be any sense that it's OK to install them in very much harsher environments, but not domestic ones, with nobody giving any sensible reason for it.