16 amp commando sockets. 20 amp mcb on site guide as maximum value mcb

[David Rann]

Hello the on site guide lists 20 amp maximum mcb for 16 amps sockets. Having a debate with someone as to why this is? Why not 16amp mcb? I installed 20 amp mcb as it's for a car charger that charger's at 16amps for 8 hours and is not capable of pulling more than 16 amps but this has been pulled as a C2. I didn't install 16amp as have in the past and over time the bi metallic strip has worn and started to trip after 12 months or so.

Cheers

 

[telectrix]

assuming the cable is 2.5mm (or greater) then a 20A MCB is fine to protect the cable. as it's a dedicated load incapable of overloading the 16A socket, then i can't see a problem.

 

[Andy78]

Hello the on site guide lists 20 amp maximum mcb for 16 amps sockets. Having a debate with someone as to why this is? Why not 16amp mcb? I installed 20 amp mcb as it's for a car charger that charger's at 16amps for 8 hours and is not capable of pulling more than 16 amps but this has been pulled as a C2. I didn't install 16amp as have in the past and over time the bi metallic strip has worn and started to trip after 12 months or so.

Cheers

Who has coded it a C2 issue ?
Have they quoted a regulation that it does not comply with ?

 

[westward10]

You can use 20A to supply 16A sockets but I would only do this if the circuit supplied more than one. If it is one socket I would not use 20A.

 

[David Rann]

I have gone back with page 184 on IET on site guide 20 amp maximum. It's 2.5mm over 10 meters. I don't know who has gave it a c2 as this is coming from the customer I did the job for 18 months ago.

 

[David Rann]

Why is this?

 

[David Rann]

You can use 20A to supply 16A sockets but I would only do this if the circuit supplied more than one. If it is one socket I would not use 20A.

Why is this? Can you show me a regulation number? Cheers

 

[telectrix]

then get the customer to enquire as to the specific regulation that applies to this C2.

 

[westward10]

Why is this? Can you show me a regulation number? Cheers

No but I do not see the sense in putting a single 16A socket on a 20A protective device.

 

[David Rann]

I have gone back and asked him for reg number. This was a few days ago. Still not heard anything.

 

[David Rann]

No but I do not see the sense in putting a single 16A socket on a 20A protective device.

Because it's an ev charger and like I said in the original post charges for 16 amps constant. Over time I have had them wear the bi metallic strip and start to trip. 20 amps takes the stress off and complies with IET on site guide.

 

[telectrix]

I have gone back and asked him for reg number. This was a few days ago. Still not heard anything.

because there isn't one.

 

[David Rann]

Well I will wait and see what they come back with. Part of me thinks they are on a ....that needs changing we can do it now for £200

 

[westward10]

Sounds like the 16A socket is not big enough.

 

[David Rann]

Sounds like the 16A socket is not big enough.

Possibly but never had an issue with the commandos only the breakers.

My point being if you are going to C2 something you need to back it up with a regulation otherwise it's just an opinion?

Cheers

 

[westward10]

I wouldn't Code it at all but if a 16A device trips then it is inadequate for the connected load and this must also apply to the 16A socket, change it to a 32A socket.

 

[David Rann]

Can't change it to a 32amp as it's a fixed adapter with electronics inside.

 

[telectrix]

if the charger is designed to plug into a 16A socket, then the 16A socket is sufficient.

going by the argument of whoever coded it, that means we need to fit 13A socket circuits with a 13A MCB.

 

[Simlec]

20 amp should be fine supplying your 16amp socket as you say its covered in OSG part H3.
Out of interest have you hit mainly drains installing your earth rods for your EV chargers ?

 

[David Rann]

20 amp should be fine supplying your 16amp socket as you say its covered in OSG part H3.
Out of interest have you hit mainly drains installing your earth rods for your EV chargers ?

I don't know! Scary every time though. Bought a cat scanner for cables but still!! 18th edition takes out the "where reasonably practical" bit. So expect a lot of People hitting utilities