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[Glan gluaisne]

In terms of price, then an earth electrode, clamp, buried box, cable etc will be around £40 or so About half this if a buried box isn't needed). If an additional length of rod is needed, then add a fiver. A Type B RCBO is now down to about £80, so the materials side of an earth electrode type installation would be around £120 or so. 99% of the time either a single rod, or an extension rod screwed on top, will get Ra down below 200 Ohms OK. The idea of placing additional rods 3m apart is a bit bonkers, really. If Ra can't be brought down to 200 Ohms or less with two rods screwed together (pretty rare) then just boring a post hole, filling it with Bentonite, and banging the rods back in will pretty much always do the job. There's a problem with skills fade when it comes to using earth electrodes, I suspect, as they are pretty unusual in modern domestic installations; nowadays most houses will have a protective earth provided on the incoming supply, either combined with neutral (a PEN) or as a separate conductor with a split concentric incoming cable.

The Type B RCBO replaces any RCD/MCB for the installation, and provides both earth fault protection and over-current protection.

For the matt-e solution, the materials cost looks to be a fair bit higher, but it saves a bit of work and makes the installation a bit simpler, from the electricians point of view. The question is really if you're prepared to pay a modest premium in order to make the job easier for the chap doing the installation.

Nothing to choose between the two options in terms of safety, although the earth electrode and Type B RCBO will respond a great deal faster if there's an earth leakage fault, no more than 30ms. The touch voltage protection device always takes more than 4s to trip, although whether this much longer trip time is important depends on the probability of someone standing next to the car and touching it at the same time that a fault occurs.

 

[ejvee]

In terms of price, then an earth electrode, clamp, buried box, cable etc will be around £40 or so About half this if a buried box isn't needed). If an additional length of rod is needed, then add a fiver. A Type B RCBO is now down to about £80, so the materials side of an earth electrode type installation would be around £120 or so. 99% of the time either a single rod, or an extension rod screwed on top, will get Ra down below 200 Ohms OK. The idea of placing additional rods 3m apart is a bit bonkers, really. If Ra can't be brought down to 200 Ohms or less with two rods screwed together (pretty rare) then just boring a post hole, filling it with Bentonite, and banging the rods back in will pretty much always do the job. There's a problem with skills fade when it comes to using earth electrodes, I suspect, as they are pretty unusual in modern domestic installations; nowadays most houses will have a protective earth provided on the incoming supply, either combined with neutral (a PEN) or as a separate conductor with a split concentric incoming cable.

The Type B RCBO replaces any RCD/MCB for the installation, and provides both earth fault protection and over-current protection.

For the matt-e solution, the materials cost looks to be a fair bit higher, but it saves a bit of work and makes the installation a bit simpler, from the electricians point of view. The question is really if you're prepared to pay a modest premium in order to make the job easier for the chap doing the installation.

Nothing to choose between the two options in terms of safety, although the earth electrode and Type B RCBO will respond a great deal faster if there's an earth leakage fault, no more than 30ms. The touch voltage protection device always takes more than 4s to trip, although whether this much longer trip time is important depends on the probability of someone standing next to the car and touching it at the same time that a fault occurs.

Thanks..you seem to be well informed on this.

I also felt he was hard selling the MATT:E changing the story of possible multiple rods which he never mentioned when he came to scout the house a month ago.

I'm OK to spend the premium if it is safe as an earth rod

 

[Glan gluaisne]

Also worth noting that some charge points need neither an earth electrode (with Type B RCBO/RCD) or the matt-e device, as they have built-in DC earth leakage detection.

Well worth checking this, as if the charge point you're having fitted already has built-in DC leakage protection there's no point in paying for either the matt-e device or an earth electrode installation, etc.

 

[ejvee]

Also worth noting that some charge points need neither an earth electrode (with Type B RCBO/RCD) or the matt-e device, as they have built-in DC earth leakage detection.

Well worth checking this, as if the charge point you're having fitted already has built-in DC leakage protection there's no point in paying for either the matt-e device or an earth electrode installation, etc.

He said ZAPPI has this gizmo incorporated in them

 

[Adopado]

He said ZAPPI has this gizmo incorporated in them

Yes it does - at least I know the Zappi 2 does. However, they're pricey so you'll be paying for it that way.

 

[madcal]

I got an Andersen. Looks great and works well. All the others have cables lying around or look like a 5 year old built them.
Andersen can load share over multiple chargers also when I buy the next one.

I wouldn’t buy a Tesla one as maybe I won’t always have Teslas.

Lead time now reducing on the Andersen units too.

 

[MrBadger]

I wouldn’t buy a Tesla one as maybe I won’t always have Teslas.

Tesla is a regular Type 2 equipped charger so in its default configuration will charge any Type 2 ported car.

 

[Glan gluaisne]

I recently came across a £300 charge point that includes DC leakage protection, this one: QUBEV - EV Charging Unit | Type 2 Socket | 32 Amp/7.2 kW | IP65 |

It's a socket unit, rather than a tethered cable, but includes variable charge current. It's not smart, so isn't eligible for the OLEV grant, but looks to be easy to install, as it just needs a feed with a Type A RCBO for protection. No idea what it's like, I came across it whilst looking for something else.

 

[jimbo_hippo]

Tesla is a regular Type 2 equipped charger so in its default configuration will charge any Type 2 ported car.

Furthermore, with an adaptor it will charge others. We charge a Model 3 and a 2017 Leaf 30kW with out Tesla Wall Connector. The Leaf is type 1 and (with a little caveat that you have to hold the catch up for 10 seconds when plugging in) charges the Leaf just fine.

 

[Glan gluaisne]

Furthermore, with an adaptor it will charge others. We charge a Model 3 and a 2017 Leaf 30kW with out Tesla Wall Connector. The Leaf is type 1 and (with a little caveat that you have to hold the catch up for 10 seconds when plugging in) charges the Leaf just fine.

I think I know the reason for needing to disable the Leaf protocol controller (by keeping the proximity switch open) for ~10 seconds. This morning I looked at the communications protocol that the Tesla UMC uses, and I suspect the Tesla wall charge point may be the same. The protocol is non-standard (and not really compliant, either) as for the first 5 seconds after the car connector is plugged in the UMC signals that it's using the DC charging protocol (really odd thing to do) by setting the duty cycle on the control pilot to about 3.2%. This is a non-standard signal, and so the chances are that the Leaf may detect it and throw a wobbly. By keeping the proximity switch open during this period, I suspect that the Leaf protocol controller will not be listening on the Control Pilot, so misses this bit of odd signalling. After 5 seconds the UMC advertises the set current as being available, by setting the duty cycle to a figure above 10%.

 

[jimbo_hippo]

I think I know the reason for needing to disable the Leaf protocol controller (by keeping the proximity switch open) for ~10 seconds. This morning I looked at the communications protocol that the Tesla UMC uses, and I suspect the Tesla wall charge point may be the same. The protocol is non-standard (and not really compliant, either) as for the first 5 seconds after the car connector is plugged in the UMC signals that it's using the DC charging protocol (really odd thing to do) by setting the duty cycle on the control pilot to about 3.2%. This is a non-standard signal, and so the chances are that the Leaf may detect it and throw a wobbly. By keeping the proximity switch open during this period, I suspect that the Leaf protocol controller will not be listening on the Control Pilot, so misses this bit of odd signalling. After 5 seconds the UMC advertises the set current as being available, by setting the duty cycle to a figure above 10%.

Jeremy, I knew there was a reason I warm to your crinkly bob-hatted face. This sounds to be about right in practice. If I don’t hold up the catch, the LEAF performs a series of bleeps and simply says no. The Tesla wall connector turns red meaning there’s a fault and nothing happens no matter how long you leave it.

for completeness, without the hold on the catch, the wall charger shows red but doesn’t need a reset so I can only assume it considers this a protocol error and not a dangerous electrical fault. I’ll leave that very basic diagnosis in your far more capable hands Jeremy.

FYI, the adaptor is this one. No idea if it’s just a pin to pin patch or if it has any intelligence. I suspect the former. Type 2 to Type 1 Converter

 

[MrBadger]

As I understand it there is a switch inside the TWC that controls whether Tesla comms is used or a more standard comms. I don’t know for sure but think it may be worded something like legacy protocol - I think this may also prevent non recent Tesla vehicles from charging, say at a Tesla vehicle specific destination charger - not been in a position to try a non Tesla into a ‘Tesla Only’ destination charger to know if it’s real exception or just signage.

 

[Glan gluaisne]

As I understand it there is a switch inside the TWC that controls whether Tesla comms is used or a more standard comms. I don’t know for sure but think it may be worded something like legacy protocol - I think this may also prevent non recent Tesla vehicles from charging, say at a Tesla vehicle specific destination charger - not been in a position to try a non Tesla into a ‘Tesla Only’ destination charger to know if it’s real exception or just signage.

Sounds reasonable to me. From what I saw on the 'scope this morning the Tesla UMC (and I'd guess the TWC, too) seems to initially try and tell the car that it's using what we now refer to as the DC charge signalling protocol (essentially sending a signal with a duty cycle of between 3% and 8%). If it doesn't sense a response within 5 seconds, it reverts to the standard protocol, and starts advertising with the appropriate duty cycle on the Control Pilot (between 10% and 85%, but in reality probably not much more than about 50% (30 A) here).

It may be that this is used to lock out Tesla-only AC charge points, as, despite using the same connector, many (perhaps most) non-Teslas would throw a wobbly if presented with a CP signal like this, I suspect. I'm in the middle of modifying the code for my charge point, so that it exactly simulates the signalling that the UMC uses. My hope is that this may wake the car up if it's sleeping, so allowing the charge point to control charging, rather than the car.

 

[madcal]

Based on all that I would find it easier with my Andersen which is a similar price to Tesla but doesn’t get moody with other cars!

 

[MrBadger]

Based on all that I would find it easier with my Andersen which is a similar price to Tesla but doesn’t get moody with other cars!

If it was a problem I think you would hear people moaning about not being able to use Tesla destination chargers on their non Tesla car.

 

[Glan gluaisne]

If it was a problem I think you would hear people moaning about not being able to use Tesla destination chargers on their non Tesla car.

More than 50% of Tesla destination charge points will not work with non-Teslas. A hotel we visit regularly has three Tesla charge points, all appear to be Type 2, but two of them will only charge Teslas, and don't work with any other EV. I believe this was a condition under which Tesla supplied destination charge points.

 

[arg]

what we now refer to as the DC charge signalling protocol

Per the standards, the 5% pilot (5% nominal, 3%-7% tolerance range) is not actually DC charging, it's merely "Digital communication", and it is specified for use with AC charging also - where it would be potentially useful for managed charging (ie. to let the chargepoint know how much charge the car actually wants), and could also allow the payment mechanism from CCS2 to be used on AC public chargepoints. I'm not sure how many cars actually implement it though.

However, "digital communication" is supposed to mean the RF carrier superimposed on the pilot (plus IP packets, XML etc.), but Tesla have long abused it to mean their own version of digital communication where they do a low-bitrate single-ended CANbus over the pilot pin. Originally this was just for superchargers; then the 2nd-generation Wall Connector (the only version sold in Europe) started doing it, apparently for better management of the load sharing, though the WC also has current measuring so it can still load-share with non-Tesla vehicles. Now you tell us that the UMCv2 is also doing it, though less clear what benefit it brings there.

I also haven't heard whether Model 3 at CCS-plug superchargers speaks standards-based Digital Communication or still uses Tesla's scheme: clearly the cars support both.

 

[arg]

It seems to provide protection based on sensing the CPC voltage, in accordance with this get-out in Section 722.411.4.1 :

Unfortunately, the longer-form manual suggests it is a supply voltage monitoring device only, and hence doesn't comply with the current 722.411.4.1(iii) (especially is the manual tells you it is self-resetting).

So it's much the same as PodPoint have internally on their units.

It might become permitted under the proposed new 722.411.4.1(iv) for which the public comment period has just finished. It was interesting to read the comments from the manufacturers of Zappi, who think there isn't the headroom to make a supply-voltage based unit operate reliably, particularly with embedded generation potentially raising the voltage inside the installation above limits (even while the supply itself is just within limits - volt drop running in the reverse direction to usual). They favour directly measuring the current in the CPC.

It will be a few months while this plays out.

 

[arg]

The idea of placing additional rods 3m apart is a bit bonkers, really.

Note that the scenario for placing multiple rods 3m apart suggested in the Code of Practice isn't to get Ra<200R in poor ground for a TT earth, rather it's to get down to single figure resistance for placing in parallel with the PME earth in cases where TT isn't acceptable (eg. other PME-earthed metalwork in the vicinity).

It's still bonkers though!

 

[Aye_Watt]

I got an Andersen. Looks great and works well. All the others have cables lying around or look like a 5 year old built them.
Andersen can load share over multiple chargers also when I buy the next one.

I wouldn’t buy a Tesla one as maybe I won’t always have Teslas.

Lead time now reducing on the Andersen units too.

The OLEV + EST subsidised standard install of my Rolec is creeping up towards Andersen/Tesla pricing. What would be a fair price if I choose Andersen or Tesla?