Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Home UMC Charging

GrahamW42

Member
Dec 31, 2018
43
13
Thirsk
I currently use a 13A 3-pin plug via UMC to charge my 2016 MS. I would like to kick it up a notch.

I keep reading about home charging solutions that cost many hundreds of pounds.

AIUI a "simple" blue commando socket (with RCD) will allow me to triple my charge rate with my existing set up.

a) Is this right ?
b) Am I missing something that an expensive installation will provide ?


If this is a stupid question ... please be kind.
 

Glan gluaisne

Supporting Member
Sep 11, 2019
2,782
2,708
UK
I currently use a 13A 3-pin plug via UMC to charge my 2016 MS. I would like to kick it up a notch.

I keep reading about home charging solutions that cost many hundreds of pounds.

AIUI a "simple" blue commando socket (with RCD) will allow me to triple my charge rate with my existing set up.

a) Is this right ?
b) Am I missing something that an expensive installation will provide ?


If this is a stupid question ... please be kind.

Yes, having a commando socket installed will allow you to charge at 16 A with the UMC, or even 32 A with the optional adapter from Tesla. However, a commando outlet for charging needs to meet the same safety requirements as a charge point installation, so may not be really cheap. I started a thread to look at some budget charge point options here, that includes having a commando outlet installed: Basic charge point costs

As you're in Scotland, Part P of the building regs doesn't apply, which means that any electrician can do the work, unlike England and Wales where only someone who is a member of one of the part P accreditation bodies can do it. Might make a small difference to the installation cost, although it would be to the labour cost element, and I didn't detail that in the other thread.
 

eight

Member
Sep 19, 2020
72
50
Stockport
I’ve done exactly that - DIY’d 32 amp blue commando socket is charging my MS quite happily via some 10mm cable and an rcd protected mcb.
I used a decent quality interlocking gewiss socket from eBay.
Technically I’m going to be killed to death as the rcd regs are difficult to meet on the cheap from advice on here but I’ve been charging evs on a brick charger using exactly the same supply method for 5 years and never got electrocuted once. Yet.

Moderator comment - this posts contains information that may be unsafe and non compliant/illegal in some areas areas where this post may be read - please consult a suitably qualified electrician when installing electrical equipment of this nature.
 
Last edited by a moderator:
  • Funny
Reactions: Adopado and rotor2k

Glan gluaisne

Supporting Member
Sep 11, 2019
2,782
2,708
UK
I’ve done exactly that - DIY’d 32 amp blue commando socket is charging my MS quite happily via some 10mm cable and an rcd protected mcb.
I used a decent quality interlocking gewiss socket from eBay.
Technically I’m going to be killed to death as the rcd regs are difficult to meet on the cheap from advice on here but I’ve been charging evs on a brick charger using exactly the same supply method for 5 years and never got electrocuted once. Yet.

If you're OK with breaking the law, with a maximum penalty of an unlimited fine and up to two years imprisonment, as well as possibly endangering life, which may carry additional charges and penalties, then that's fine.

Having once spent a lot of time, over a period of around three years, trying to help defend someone who had been charged with manslaughter for a failure to take the expected level of care over a very simple task, it's not something I would ever knowingly do, or advise others to do. The probability of something going wrong may be low, but the consequences, should the worst happen, could be devastating.

I'm also not sure that this forum should sanction unlawful activity, but that's something for the moderators to determine.
 
  • Like
Reactions: m3p_uk and Roy W.

eight

Member
Sep 19, 2020
72
50
Stockport
All true.
To be safe, legal and able to claim on your house insurance should you need to, get a fully qualified professional to install your charge point.
I’m not qualified or professional so please disregard what I have done.
As per OPs question - yes a 32A commando will do exactly what you thought, but as above in terms of correct and proper install cost you may as well just get a type 2 wall charger.
 

Medved_77

TM3 SR+ | MSM+Black | No FSD
Jan 20, 2020
2,044
2,064
Scotland
I currently use a 13A 3-pin plug via UMC to charge my 2016 MS. I would like to kick it up a notch.

I keep reading about home charging solutions that cost many hundreds of pounds.

AIUI a "simple" blue commando socket (with RCD) will allow me to triple my charge rate with my existing set up.

a) Is this right ?
b) Am I missing something that an expensive installation will provide ?


If this is a stupid question ... please be kind.
If you're in Scotland have you looked into the grants available for a Type 2 home charger?

My PodPoint unit was £859 for the unit and installation. I got £500 in grants from the UK and another £300 from Scotland so paid £59 only.

Grants have been reduced slightly but if you're eligible you should be able to get the unit and installation for less than £200.
 

fancealot

Member
Jun 17, 2020
237
155
Doncaster & Leeds
If you're in Scotland have you looked into the grants available for a Type 2 home charger?

My PodPoint unit was £859 for the unit and installation. I got £500 in grants from the UK and another £300 from Scotland so paid £59 only.

Grants have been reduced slightly but if you're eligible you should be able to get the unit and installation for less than £200.

THIS!! Definitely look into the grants, plus life cycle of the charging points and ability to use on a number of EV's (so eventually if you get a second EV or swap EV's you have a solution all ready to go. Then you can keep the UMC in the boot for emergency use only (which I know others use long term but Tesla would prefer it to be a temporary stop gap)
 

Adopado

Active Member
Aug 19, 2019
3,801
2,910
Scotland
If you're OK with breaking the law, with a maximum penalty of an unlimited fine and up to two years imprisonment, as well as possibly endangering life, which may carry additional charges and penalties, then that's fine.

But aren't we all breaking the same law when charging via a non-EV dedicated 13amp socket using the UMC? I've never quite got my head around why it's OK to use the UMC with a 13amp socket yet if we plug in via a commando socket we have to meet all the regs.
 

rjinski

Member
May 29, 2020
34
5
London, UK
But aren't we all breaking the same law when charging via a non-EV dedicated 13amp socket using the UMC? I've never quite got my head around why it's OK to use the UMC with a 13amp socket yet if we plug in via a commando socket we have to meet all the regs.

Intention. If the commando was installed to use a table saw but you used it to charge the car I guess it would be... ok? Just like the 13A sockets were not installed to charge the car?
 

VanillaAir_UK

Supporting Member
Jun 17, 2019
7,971
5,466
Surrey, UK
I believe [cannot remember the source] that the regulations may relate to devices only over 10A. So UMC and '13A' plug may be outside this. Obviously safety still applies at any current.
 

GrahamW42

Member
Dec 31, 2018
43
13
Thirsk
Firstly, apologies for setting off a hand grenade in the "regs" and "legalities" debating arena !

Secondly, whilst I've nothing against Scotland, I don't live there. Thirsk is in Yorkshire !

Glan, thanks for an excellent reply - especially that link to your post including costings. My mistake was to assume that a commando socket would cost very little. As it seems to cost a substantial amount, the relatively small increment for a dedicated wall charger s probably worth the benefit of keeping the UMC with you in the car (and having a tidier garage).
 

Glan gluaisne

Supporting Member
Sep 11, 2019
2,782
2,708
UK
But aren't we all breaking the same law when charging via a non-EV dedicated 13amp socket using the UMC? I've never quite got my head around why it's OK to use the UMC with a 13amp socket yet if we plug in via a commando socket we have to meet all the regs.

Just to clarify, the law relates to the installation, rather than the usage, plus the regulations that apply to an installation are different to the regulations that apply to appliances. This means that a user of an appliance (the UMC in this case) is not required to comply with any regulations, they just have to use a bit of common sense, i.e. not leave the exposed 13 A plug out in the rain, for example.

If a weatherproof 13 A outlet is installed outside, then it has to be RCD protected, and has been for years, because there's long been recognition that the probability of getting an electric shock from anything plugged in outdoors is significantly higher than from something plugged in indoors.

Intention. If the commando was installed to use a table saw but you used it to charge the car I guess it would be... ok? Just like the 13A sockets were not installed to charge the car?

Following on from the above, it comes down to whether or not the installer believes that the purpose of an outlet is to charge an EV. If the installer believes, or suspects, that any outlet is to be used for EV charging (i.e. the customer has an EV and has asked for an outlet to be installed close to where they park their car) then the installer is obliged to install it in accordance with Section 722 of the regs. In the case of outdoor commando outlets, they usually end up being installed with open PEN protection and an RCD anyway, as nine times out of ten in a domestic scenario they are used for things that require this, like running power to a caravan, and there has always been a requirement for such an outlet to be protected like this.

I believe [cannot remember the source] that the regulations may relate to devices only over 10A. So UMC and '13A' plug may be outside this. Obviously safety still applies at any current.

As above, the difference is between an appliance (in this case the UMC) and an installation (an outlet intended for EV charging, such as a commando or a charge point).

The intention behind allowing the UMC to be used, without the same level of protection as a charge point, is really because the UMC isn't intended to be a permanent, everyday, charging solution. The UMC is about as safe as an appliance can be, and does have integral DC sensitive RCD protection, but that RCD protection doesn't comply with the standard required for an installation (as it's not installed equipment) and also the UMC cannot provide protection from an open PEN fault. I believe the assumption is that, as the UMC is unlikely to be used as an everyday charger, and as it's a very useful "get out of jail" charging method, the risk posed by not having open PEN protection is acceptable. Given that there are loads of charge points installed without open PEN protection, because some installers just haven't bothered to fit it, it's probably a reasonable view.
 

Glan gluaisne

Supporting Member
Sep 11, 2019
2,782
2,708
UK
Firstly, apologies for setting off a hand grenade in the "regs" and "legalities" debating arena !

Secondly, whilst I've nothing against Scotland, I don't live there. Thirsk is in Yorkshire !

Glan, thanks for an excellent reply - especially that link to your post including costings. My mistake was to assume that a commando socket would cost very little. As it seems to cost a substantial amount, the relatively small increment for a dedicated wall charger s probably worth the benefit of keeping the UMC with you in the car (and having a tidier garage).

Just to pick up on your last point, if you have an attached garage, and intend to install a charge point in it, with the lead not being long enough to run outside the garage, then you don't need to use any form of open PEN protection. This means that all that's needed is overcurrent protection and a Type B RCD (or Type EV RCD, but they aren't common). This means there's no need to install either an earth electrode etc, or an open PEN protection device, which saves a bit of money.

If the garage is detached, then it's a judgement call by the installer as to whether open PEN protection is needed. That decision depends on thing like the distance from the house to the garage, plus the nature of the incoming supply, plus the nature of any existing garage electrical installation. As an example, our garage is about 30m away from the house, so in my view it was a separate electrical installation. Because exporting the PE (protective earth) runs a small risk of introducing a potential earth fault (losing the exported connection) I chose to fit an earth electrode to our garage installation and wire it as a TT installation. This means that the charge point I have in the garage has open PEN protection, along with all the other electrical outlets in there.

As a final point, open PEN protection is not needed if the whole house electrical installation is wired as a TT installation, with an earth electrode and RCD on the incoming supply.
 

GrahamW42

Member
Dec 31, 2018
43
13
Thirsk
It's going to be an attached garage. It's still being built. There's a good chance the main fuse box may actually be IN the garage.

I'll have a word with the builder to see if, after your comments re no need for PEN protection, a commando solution may be cheap enough to be attractive to me.
 

Glan gluaisne

Supporting Member
Sep 11, 2019
2,782
2,708
UK
It's going to be an attached garage. It's still being built. There's a good chance the main fuse box may actually be IN the garage.

I'll have a word with the builder to see if, after your comments re no need for PEN protection, a commando solution may be cheap enough to be attractive to me.

If it's still being built, and they haven't yet done first fix in the garage, then that's a golden opportunity to put the cabling in, ready for whatever charging solution you choose. I doubt there's a massive difference in cost between a commando and a budget charge point for a new build, TBH. Labour is usually a big chunk of the cost, and much of the labour cost is the cost of mobilising the electrician and his/her overheads, so adding an hour or so's work to run a cable for a charge point isn't going to be a lot extra.

There were plans a while ago to ensure that all new builds were wired such that adding a charge point would be easy, by putting the capacity in the installation, both from the supply side and having a suitable slot in the CU spare. Unfortunately I don't think it's yet made its way into any formal minimum standard, which is a shame, given that it wouldn't add much to the cost of building a house. I cabled our house up for two charge points when I built it, as well as running cables to pretty much anywhere I thought we might want power in future, like the shed, greenhouse, garden and driveway lights, even cables out to a space that's going to have a small shed fitted soon, for a second freezer and battery storage.
 

tsh2

Member
Aug 27, 2019
290
83
Cambridge, UK
There were plans a while ago to ensure that all new builds were wired such that adding a charge point would be easy, by putting the capacity in the installation, both from the supply side and having a suitable slot in the CU spare.
I'm sure all the (few) recent applications I've seen have specified the whole EVSE installed. Maybe it is a local council choice, or the developers just deciding it will ease the process, these properties being high value anyway...
 

Country Boy

Member
Oct 8, 2020
80
30
Herefordshire
John Ward is a bit of a legend when it comes to wiring regulations, though his delivery is a little dry.

Have a look at


This is a rundown of the latest amendment to the regulations. If the output of the EVSE (charger to you and me) is 10A or less, the regulations don't apply... If more than 10A, they do whether they are a fixed installation or a 32A commando with the UMC.
 

Glan gluaisne

Supporting Member
Sep 11, 2019
2,782
2,708
UK
John Ward is a bit of a legend when it comes to wiring regulations, though his delivery is a little dry.

Have a look at

This is a rundown of the latest amendment to the regulations. If the output of the EVSE (charger to you and me) is 10A or less, the regulations don't apply... If more than 10A, they do whether they are a fixed installation or a 32A commando with the UMC.

Whilst I think that "droning John Ward" is usually spot on with most things, there is nothing in the regs at all that differentiates between an outlet intended for charging a normal road-going electric vehicle, based on current. The mention of 10 A only applies to, (quoted directly from Amendment 1 to BS7671:2018):

722.1 Scope

The particular requirements of this section apply to circuits intended to supply electric vehicles for charging purposes.

The requirements of this section do not apply to electric vehicle charging points that:

(i) employ inductive charging

(ii) charge mobility scooters and similar vehicles of 10 A and less.

This section makes it clear that the =<10 A exception ONLY applies to "mobility scooters and similar vehicles". A normal road-going electric car definitely doesn't fall within this category.
 
  • Informative
Reactions: Adopado

Avendit

Member
Apr 18, 2019
817
535
EDI
It's going to be an attached garage. It's still being built. There's a good chance the main fuse box may actually be IN the garage.

I'll have a word with the builder to see if, after your comments re no need for PEN protection, a commando solution may be cheap enough to be attractive to me.

I was off down this route - new garage as part of an extension being built, temporally charging on a self installed 16A comando. It works, it hasn't killed any one, I am very careful about treating that UMC well and doing what I can to ensure potentially dangerous faults don't develop. About £50 of parts and monitoring the solution with an IR camera I have to make sure all the connections are solid.

Garage was prepped to accept a 32A charger with an extra supply run from the main unit in the house to the garage, but our electricians aren't certified to fit charge points, so I went shopping.

I was going to get an EO Mini Pro as being small/cheap. Then realised that sticking that on the front of a new extension was a sin and switched to an Andersen. It came to ~£1300, but it looks the part in a way the EO never would have, and the Scottish gov gave me £300 back, eventually. All installed and working now, although I still can't get the car in the drive as that hasn't been done yet :(.
 

Glan gluaisne

Supporting Member
Sep 11, 2019
2,782
2,708
UK
Those in Scotland (and Northern Ireland) have the distinct advantage that they don't (yet) have Part P in Scottish Building Regs, so a DIY install isn't likely to end up with them getting an unlimited fine or up to 2 years imprisonment.

The same wiring regulations apply in Scotland as in England and Wales, and the requirement still exists that anyone that installs equipment like this has to be competent, but, for example, I could legally install a charge point there, whereas down here, despite being competent, I cannot, as the part P accreditation bodies will not allow a retired person to remain a member.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top