Thickness of UMC charging cable

[GarethWhyte]

Hello Everyone,

Silly question, in the absence of a charge at home because of the Garage power not being sufficient, I’m having some external powerpoints added.

Can anyone let me know the ‘thickness’ of the cable attached to the three pin plug so I can ensure the socket has a big enough hole?

Thanks!

 

[bjhinkle]

You’ll need to provide more technical information.
If you are running a 60 amp circuit, you’ll need to use 6 gauge wire from your service, which I used 3/4” conduit.

Moderator comment - details not relevant to OP's region

 

[LukeUK]

Are you referring to the diameter of the cable, so that you can check that the the sealing gland of an IP rated external socket cover will work ok?

If so, the UMC itself isn't going to enjoy being left dangling outside of an external wall socket, for any significant period of time, in rain, etc.

It would be better to house the entire UMC inside a rain-proof enclosure, if you can.

Also, if you're adding external sockets, you could look at adding a 16A 'blue' socket, and purchasing the additional 16A plug UMC adapter, which would increase your charging rate from 10A to 16A. You would need to make sure that the supply cable for the 16A socket(s) was properly rated and protected.

 

[LukeUK]

You’ll need to provide more technical information.
If you are running a 60 amp circuit, you’ll need to use 6 gauge wire from your service, which I used 3/4” conduit.

Pretty much irrelevant for a UK installation. Our voltage is 230V, so 60 A is not required, even for a UK standard 7 kW single phase charger (32 A), and our wire sizes are measured by cross-sectional area (CSA), in mm².

 

[Glan gluaisne]

Hello Everyone,

Silly question, in the absence of a charge at home because of the Garage power not being sufficient, I’m having some external powerpoints added.

Can anyone let me know the ‘thickness’ of the cable attached to the three pin plug so I can ensure the socket has a big enough hole?

Thanks!

Non-switched single gang BG weatherproof outdoor outlets are just about perfect, as the chunky plug on the UMC fits fine and the cover seals well around the cable. I believe that the switched 2 gang BG units are the same, but know that the switched single gang outlet doesn't work well, as the plug is offset from centre, so the lead doesn't line up with the seal.

You’ll need to provide more technical information.
If you are running a 60 amp circuit, you’ll need to use 6 gauge wire from your service, which I used 3/4” conduit.

We do not use American Wire Gauge here, all cables are dimensioned in terms of the cross section of the main conductors, in mm². Also, we do not have 60 A as a standard circuit rating here, and a typical outdoor radial running an outlet for the UMC would be protected by either a 16 A or 20 A over-current protection device, together with a mandatory (for any new installation) residual current device.

A dedicated circuit intended for charging an EV, whether it be a weatherproof 13 A outlet, an interlocked commando socket outlet or a charge point, has to be installed to comply with BS7671:2018 section 722. This means that the cable supplying it needs to be protected against overcurrent, plus the installation must have DC tolerant residual current protection and also open PEN protection.

TBH, although the regs require that even a humble outdoor outlet have the same level of protection as a dedicated charge point, if the person doing the installation believes that the outlet is to be used to charge an EV, I think I'd settle for just having the outdoor outlet connected as a TT installation, and protected by a normal Type A RCD/RCBO. The UMC does have pretty good earth leakage protection, so the main concern would be making sure that the outlet has some form of open PEN protection, and banging in a rod and wiring it as TT is far and away the simplest and cheapest way to provide this.

 

[GarethWhyte]

Are you referring to the diameter of the cable, so that you can check that the the sealing gland of an IP rated external socket cover will work ok?

If so, the UMC itself isn't going to enjoy being left dangling outside of an external wall socket, for any significant period of time, in rain, etc.

It would be better to house the entire UMC inside a rain-proof enclosure, if you can.

Also, if you're adding external sockets, you could look at adding a 16A 'blue' socket, and purchasing the additional 16A plug UMC adapter, which would increase your charging rate from 10A to 16A. You would need to make sure that the supply cable for the 16A socket(s) was properly rated and protected.

Thanks for replying, to be honest electrics is beyond me! I’ll suggest the Blue commando socket and see what they say.

be good to get the best charge I can! Thanks

 

[Glan gluaisne]

Thanks for replying, to be honest electrics is beyond me! I’ll suggest the Blue commando socket and see what they say.

be good to get the best charge I can! Thanks

If you opt for a commando outlet, then make sure it's an interlocked one, so there is no chance you can pull it out with power connected. Also make sure the electrician installing it understands the requirements of Section 722 of BS7671:2018 Amendment 1. He will have a copy of this, and may well be familiar with it, but the blue book is a mighty tome that few will know from cover to cover. Section 722 is probably only familiar to those who have fitted an outlet for car charging, my guess is that some may not be familiar with it.

 

[Country Boy]

As always, the answer is, "It depends"

I would always plan for a 32 amp supply. 6mm Twin and Earth, or Steel Wire Armoured cable unless the able run is very long.

 

[Glan gluaisne]

As always, the answer is, "It depends"

I would always plan for a 32 amp supply. 6mm Twin and Earth, or Steel Wire Armoured cable unless the able run is very long.

There are two key factors relating to cable sizing, making sure the voltage drop is within limits (not greater than 5%) and also complying with the charge point MIs. Most of the time the MI's will state 6mm, and also state that the supply should be protected with a 40 A MCB. A 32 A MCB is marginal for a circuit that's going to be running at 32 A for several hours - a 32 A MCB is going to get pretty warm after 6 or 7 hours of running at 32 A.

To give the required mechanical protection it will need to be either SWA or NYY-J cable, or otherwise suitably protected, depending on the location. At a pinch, T&E could be used in conduit for an indoor (i.e in a garage) installation, but 6mm T&E is a tight squeeze in 20mm HD conduit, so that means going up to 25mm, and that may not easily fit the charge point cable entry, as they are often 20mm diameter. In practice, the vast majority of installations use 6mm SWA, although most could be cabled in NYY-J. For some reason NYY-J isn't popular, odd, as it's less hassle to terminate and can go through a much cheaper gland.

 

[Gatsojon]

12 mm outer diameter

 

[LongRanger]

The tesla UMC 16a commando is 2.5mm sq cable and the 32a is 6mm sq

 

[Glan gluaisne]

The problem area when plugging the UMC into an outdoor outlet isn't usually the cable diameter, it's the extended moulding from the plug that supports the cable. Some outdoor outlets don't have room for this under the lid. For example, a BG single gang switched weatherproof outlet doesn't work, as the thick part of the plug moulding fouls on the case and stops the plug being fully inserted, like this:

However, the non-switched version of the same weatherproof outlet is fine, as the socket is aligned with the cable seal, and the plug fits OK:

The BG non-switched single gang outlet, and the BG switched double gang outlets, are the only ones I know of that are definitely large enough to take the Tesla UMC plug. Some others might also have enough clearance, but would need to be checked to make sure.

 

[LongRanger]

Really like the BG stuff have got this throughout the outbuildings and recently had the 30 year old outdoor sockets replaced with the double-switched BG.

 

[Adopado]

The problem area when plugging the UMC into an outdoor outlet isn't usually the cable diameter, it's the extended moulding from the plug that supports the cable. Some outdoor outlets don't have room for this under the lid. For example, a BG single gang switched weatherproof outlet doesn't work, as the thick part of the plug moulding fouls on the case and stops the plug being fully inserted.....

However, the non-switched version of the same weatherproof outlet is fine, as the socket is aligned with the cable seal, and the plug fits OK:

In case anyone already has one of these single BG outside sockets, but with the offset switch, you can replace the socket plate with a non-switched version without having to replace the rest of the fitting. The one that matches (and therefore fits perfectly) is a BG Nexus 823.