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3 pin plug charging cable [UMC] query
- Thread starter gdallas
- Start date
bctomuk
God
Page 2 (page 4 of the pdf)
https://www.tesla.com/sites/default...ocs/gen_2_umc/Gen2_Mobile_Connector_en_EU.pdf
I didn't read the instructions that came with the charger.
Now I have and it raises questions.
1. If I buy a 3-pin IEC 60309 adaptor and fit a matching £30.00 "Commando" socket in my Garage why did I spend £400 on a smart charger.
2. Who writes the instructions? When I read warnings such as " Warning: Do not plug the Mobile Connector into an electrical outlet that is submerged in water or covered in snow. If, in this situation, the Mobile Connector is already plugged in and needs to be unplugged, turn off the breaker before unplugging the Mobile Connector." If Tesla's lawyers think this is important I worry about the survival of the human race.
Now I have and it raises questions.
1. If I buy a 3-pin IEC 60309 adaptor and fit a matching £30.00 "Commando" socket in my Garage why did I spend £400 on a smart charger.
2. Who writes the instructions? When I read warnings such as " Warning: Do not plug the Mobile Connector into an electrical outlet that is submerged in water or covered in snow. If, in this situation, the Mobile Connector is already plugged in and needs to be unplugged, turn off the breaker before unplugging the Mobile Connector." If Tesla's lawyers think this is important I worry about the survival of the human race.
An appropriate search on the forum will give you the answers. @Glan gluaisne gave us chapter and verse. The short version is that the electrical safety features that are part of your charge point and installation are expensive. The UMC can be plugged in without some of those features being present. That allows you to get away with plugging into an ordinary socket. Yes, you can do it with a 32 amp commando but to meet regs you really should have its installation up to EV spec ... so it will cost more than just the price of a socket and some twin and earth.
MrBadger
Badger out
Because, in England and Wales, if you have the capability to charge your car outdoors when using the socket, then the commando socket needs to be compliant with the same regulations that apply to charge points/EVSE. As many charge points have compliance built in (O-PEN and 6mA DC protection), the difference in price and installation complexity between a dedicated charge point and a compliant commando socket is not huge plus you will not be using what many would view as an occasional/backup device as a long term charging solution.
Been using the Tesla 3 pin to charge a Zoe for the last few weeks.
Jason71
Well-Known Member
They say that. But then they also say not to use an extension lead and I have used a 30m one with no issues so.....
Try it and see if it works.
MrBadger
Badger out
It doesn't matter where the socket is. If it can be used to charge a car outside, then it should be compliant to the regulations. Best way to convince that its not for EV outdoor charging is probably to stick it at the back of the garage - I'm sure that after a few charges, many would then be glad of a proper installation.
Though it doesn't meet regs it's actually an identical safety risk to using a UMC with a 13amp plug* ... which everyone does from time to time because that's what it's for! I also have a 32amp socket in the garage that can be used with the UMC at 7kW as a backup for my charge point. It's a great reassurance because once in a blue moon these fancy pants smart charge points do decide to play up!
*[Edit: In fact there's more likelihood of a 13amp socket overheating than a dedicated commando socket that's designed for high current use... that being a separate issue to the other safety issues relating to earthing and RCD functions. Nevertheless not recommending for constant use in place of a dedicated charge point.]
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This is exactly why I installed a 32A commando which I’ve been using with perfect satisfaction for nearly two years. The current might be greater in the commando but the voltage is just the same as the 3 pin plug UMC. Needless to say I wouldn’t encourage anyone else to ignore the regs but I saved myself a few hundred quid and I’m perfectly satisfied that it’s safe.
Cnixon
Member
The umc gen2 is actually pretty good wrt the Regs. If the umc and commando is inside or in an IP rated enclosure you would be better than the extension lead and plastic bag brigade (lowest standard). Just out of interest this safety bit is not just about car chargers. Its about any formally earthed metalwork outside which may get turned live if a fault occurs in the underground cable or in your home, so probably should cover lights and electric doors etc.
Cnixon
Member
A difference being that an EV is a source of dangerous voltages as well. A fault in the car itself could result in significant DC voltage coming the other way ... and if following regs requires specialized RCD protection in the supply. The blinding of standard RCDs caused by a DC fault without this can mean that, in some scenarios, life threatening voltages are possible on your home earth circuit.
Cnixon
Member
I don't think this is the issue the Regs are striving to fix. Although I don't actually think they are sure either! The regs appear to make reference to some 'Unicorn' solution which doesn't exist ....yet.
The UMC1 which supported 3 phase was a liability on other cars because of the way tesla implemented it. They effectively did 2 phase 16a on a 32a commando input which some cars had a nightmare with and caused damage (my memory is hazy but the take away is don't use a UMC1 on other cars, you might get away with a 3 pin plug but why risk it?)
The UMC2 (which is single phase only and has been shipped with all UK model 3s and the model S and X from around the time the Model 3 came out) should be fine to charge other cars. The UMC2 is also smarter as its more tolerant to live neutral being swapped (effectively earth - neutral voltage) which was a PIA in countries like France where sparkies didn't seem to care.
The commando socket regs as others have mentioned are different when used for charging. I find its a bodge that an industry standard socket has different regs at install time depending on the known usage att he time but seemingly nothing to prevent you from using an existing commando socket not installed to the regs. Why not just update the spec for everyone going forward, add a different colour code or plug type like theyhave 2 for 3 phase depending on star or delta config, etc. Tesla used to actually install commando sockets for owners back in the early days and the regs back then didn't have an EV spec. I had one until recently which worked fine (but like a lot of safety stuff, things typically do work fine until something bad happens). But that aside, installing a new circuit today for a commando socket requires a certficate from a sparky and the regs will require it to be EV spec if the sparky is aware its for charging, and given a lot of sparky cost is wiring from the consumer unit to the commando socket or charger, fitting any additional circuit protection and testing all the circuits to make sure the whole is good, I can't see a commando being a lot cheaper than getting a charger with the grant.
Finally, I also believe the main reason for the difference is DC protection and earthing as the car could wallop you with 400V DC coupled with a lot of current which I imagine isn't partiocularily healthy.
The UMC2 (which is single phase only and has been shipped with all UK model 3s and the model S and X from around the time the Model 3 came out) should be fine to charge other cars. The UMC2 is also smarter as its more tolerant to live neutral being swapped (effectively earth - neutral voltage) which was a PIA in countries like France where sparkies didn't seem to care.
The commando socket regs as others have mentioned are different when used for charging. I find its a bodge that an industry standard socket has different regs at install time depending on the known usage att he time but seemingly nothing to prevent you from using an existing commando socket not installed to the regs. Why not just update the spec for everyone going forward, add a different colour code or plug type like theyhave 2 for 3 phase depending on star or delta config, etc. Tesla used to actually install commando sockets for owners back in the early days and the regs back then didn't have an EV spec. I had one until recently which worked fine (but like a lot of safety stuff, things typically do work fine until something bad happens). But that aside, installing a new circuit today for a commando socket requires a certficate from a sparky and the regs will require it to be EV spec if the sparky is aware its for charging, and given a lot of sparky cost is wiring from the consumer unit to the commando socket or charger, fitting any additional circuit protection and testing all the circuits to make sure the whole is good, I can't see a commando being a lot cheaper than getting a charger with the grant.
Finally, I also believe the main reason for the difference is DC protection and earthing as the car could wallop you with 400V DC coupled with a lot of current which I imagine isn't partiocularily healthy.
Indeed! I'm somewhat reassured by the fact that I have yet to read of any instance of anyone ever being electrocuted by their EV. The nearest thing from a Google search was a contractor in the USA who was electrocuted whilst working on a Tesla Supercharger that was not yet commissioned... not from a car being charged. Given the hundreds of thousands of EVs around the world and the delight that some media take in pouncing on anything anti EV I think we can conclude that the likelihood of a serious problem is vanishingly small.
MrBadger
Badger out
The regs are trying to address two main issues.
The O-PEN fault condition is where the protective earth common to most households is damaged and earth starts to float at potentially dangerous voltages. Within the house, if you touch another metallic object, tap etc, that will also be at the same float voltage because they are typically bonded. However, outside, what you touch is likely not to be at the same floating voltage, but at ground voltage, so the difference in voltage between what you touch and what the supply is grounded at could be dangerously high. The solution is to ground sockets of equipment used outdoors (or double insulate) at ground level and not via the house earth, ie metal ground rods. Another solution gathering traction, is an active O-PEN detector that monitors the (earth?) voltage and if it exceeds a certain amount, iirc 80v, cuts the supply and earth. Some EVSE/charge points will have an active device built in. Hence why the regulations is for where the equipment is to be used rather than where the supply is located. One thing to watch out for is that supplies that use ground rods (not sure about active solutions) must not be located where a user can come into contact with other metal objects within the house or an internal circuit.
The main DC issue is that DC leakage is that it can blind other RCD devices causing them to be ineffective. So you can have a fault elsewhere in the house that should have been made safe by an RCD tripping but isn't because the even small DC current is preventing the RCD from doing its job. The solution is a circuit that detects >6mA DC leakage and trips the circuit - such as a B type RCD, although many EVSE/charge points have their own circuit built in.
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