[HandyAndy]

I saw a very alarming video on here recently where an old, dumb Rolec EVSE was shown continuing to charge a car, even with the Earth wire pulled out & floating in mid air!!! I've also seen a reference elsewhere to an un-named, but commonly seen in domestic situations EVSE that failed to do any Earth leakage testing. I wonder what make that might have been...

3 years ago I replaced the Rolec Controller in my 2015 Rolec, using a a Viridian controller as I wanted to be able to adjust the charging current. That controller may or may not have done better testing, but there was no additional current-transformer or other kit added, so it's hard to see how it could do better.

Viridian have now produced a much better item, their "EVSE Protovol Controller 2.0 (EPC 2.0)" which has "support for DC leakage protection and will detect DC currents of 6mA or greater, disabling the charging session and making the equipment safe". It also has "PEN Loss Detection system - the ability to protect the user in the event of a failure/loss of the PEN conductor in the distribution network. The EPC 2.0 will disconnect all live conductors and the protective earth conductor, amking the equipment safe until the fault is fixed".

This new controller supports tethered and untethered EVSEs, 16A & 32A switch-settable choice, and any other current from 6A to 32A can be set by an external resistor or supplied voltage signal, for those solar etc uses. Has a choice of 2 drivers for cable-locking motor/solenoid; I deselected this as n/a for me. A nice thing!

My EVSE is inside the gge, but car is usually on the drive when it's being charged, I could be standing in a puddle at the same time, and I believe this is one of these borderline situations where the EVSE should maybe have an Earth Rod fitted? I'm not a sparky, just wanting to be safe. I've seen a lot of mention of devices that negate the need for an Earth Rod, and I think it's this PEN Loss Detection system that permits that. So my belief is that this new Viridian EPC 2.0 is about as safe as you can get, and I gather it meets the latest regs, which maybe the original Rolec no longer would. So does this mean there are a lot of rather dangerous original-model dumb Rolecs out there? A qn I can't answer.

So I decided to get an EPC 2.0, with all the bells & whistles. EPC 2.0 is available from ecoharmony.co.uk for e.g. Usual disclaimer, no connection, just a satisfied customer.

My EVSE already had a Garo RCBO replacing the original v nasty Rolec one 3 years ago, and this stays. The Rolec Contactor seems to be ok, so that also stays. The Rolec LED light on the front panel has the wrong polarity for the original Viridians to use, so that was replaced with a clear window (v thick tape) 3 years ago. (Haven't checked the polarity on this new one, but I expect it to be the unchanged). The Viridians have built-in LEDs so you can see what state they are in.

One extra component was needed, that ecoharmony don't have on their their site, though it's shown in the circuit diagram and mentioned. This is a single pole Contactor, to isolate the Earth in case of PEN Loss. As all my other components are rated 40A (not sure about the Rolec Contactor, but is definitely 32A at least & shouldn't see > 32A ever) I wanted a 40A single pole Contactor. Garo do one, the "GK40 1NO 230V AC". Amazingly, I can only find one distributor online who stocks this, and they're in Ireland! All the other contactors seem to be 2 or 4 Pole, which is a waste of a pole, and probably more expensive than necessary. Whether you could split the Earth line and take it through 2 poles of a 2-Pole 20A contactor I don't know, but I feel this is risky as the poles are bound to open at microscopically different times, so one pole must in theory be left trying to carry a surge current of 40A at the same time as trying to kill the arc. Ok this is worst-case scenario, but that's the point, to cope with a worst-case.

Only modification to the Rolec case was to snap-off two green plates under the top waterproof lid that lets you get at the RCBO, as I put the new Contactor beside that clipped onto the standard rail, and lined the 2 items up to fit.

The EPC 2.0 comes as standard with a small Current Transformer (CT) with black & yellow twisted-wire leads, this gets the Earth wire to the car fed through it and does the PEN Loss testing. An optional extra is the RCM Residual Current Monitor which is a small box with 4 wires out, and a built-in CT; this gets the L & N wires to the car fed through it, so any imbalance means problems, current going where it shouldn't, and again a signal goes to the Viridian which shuts down the system. So now all 3 heavy-gauge wires to the car go through contactors, and all are isolated completely in case of an error. This comes with an excellent manual, and my wiring was exactly as per their supplied 230V diagram in section 6.3, they even label the terminals on the contactors & coils! Was no problem to fit this. Pics below show the new arrangement inside my Rolec, I have to say it's now a tangle of wires! But nothing's getting trapped as I close the lid (carefully!).

Prices of items (VAT included):
1 x Garo RCBO 1+N 40A char B 6kA Type A (RCBOGRB40)(A) = £ 22.02 in July 2017 (meteorelectrical.com similar today)
1 x Garo 40A Contactor 1 Pole 230V 1 Normally Open N/O AC/DC Coil Modular DIN Rail = £ 37.95 Nov 2020 (a1electrics.com, easier to search "GK40 1NO 230V AC" on eBay as payment easier, same shop.)
1 x Viridian EPC 2.0 EVSE controller & 6mA DC RCM kit (EPC20B10 + DCS6-01) = £184.80 (ecoharmony.co.uk)
+ a few short bits of wire for the new Contactor, and some wire-terminal crimps.

Total = call it £250 in round figures.

Rolec with new EPC 2.0 fitted. (BTW entire thing was isolated by small CU with Breaker & RCD both off, before you moan about the RCBO being on!)

Viridian EPC 2.0

PEN Loss CT, comes with EPC 2.0

DC Leakage Sensor / RCM Support module, located just above Rolec Contactor on LHS.

Garo Contactor on left, RCBO on right.

Rolec 32A Contactor

Rolec powered up, gently-pulsating blue Led visible through clear window.

 

[freddym]

I saw a very alarming video on here recently where an old, dumb Rolec EVSE was shown continuing to charge a car, even with the Earth wire pulled out & floating in mid air!!! I've also seen a reference elsewhere to an un-named, but commonly seen in domestic situations EVSE that failed to do any Earth leakage testing. I wonder what make that might have been...

3 years ago I replaced the Rolec Controller in my 2015 Rolec, using a a Viridian controller as I wanted to be able to adjust the charging current. That controller may or may not have done better testing, but there was no additional current-transformer or other kit added, so it's hard to see how it could do better.

Viridian have now produced a much better item, their "EVSE Protovol Controller 2.0 (EPC 2.0)" which has "support for DC leakage protection and will detect DC currents of 6mA or greater, disabling the charging session and making the equipment safe". It also has "PEN Loss Detection system - the ability to protect the user in the event of a failure/loss of the PEN conductor in the distribution network. The EPC 2.0 will disconnect all live conductors and the protective earth conductor, amking the equipment safe until the fault is fixed".

This new controller supports tethered and untethered EVSEs, 16A & 32A switch-settable choice, and any other current from 6A to 32A can be set by an external resistor or supplied voltage signal, for those solar etc uses. Has a choice of 2 drivers for cable-locking motor/solenoid; I deselected this as n/a for me. A nice thing!

My EVSE is inside the gge, but car is usually on the drive when it's being charged, I could be standing in a puddle at the same time, and I believe this is one of these borderline situations where the EVSE should maybe have an Earth Rod fitted? I'm not a sparky, just wanting to be safe. I've seen a lot of mention of devices that negate the need for an Earth Rod, and I think it's this PEN Loss Detection system that permits that. So my belief is that this new Viridian EPC 2.0 is about as safe as you can get, and I gather it meets the latest regs, which maybe the original Rolec no longer would. So does this mean there are a lot of rather dangerous original-model dumb Rolecs out there? A qn I can't answer.

So I decided to get an EPC 2.0, with all the bells & whistles. EPC 2.0 is available from ecoharmony.co.uk for e.g. Usual disclaimer, no connection, just a satisfied customer.

My EVSE already had a Garo RCBO replacing the original v nasty Rolec one 3 years ago, and this stays. The Rolec Contactor seems to be ok, so that also stays. The Rolec LED light on the front panel has the wrong polarity for the original Viridians to use, so that was replaced with a clear window (v thick tape) 3 years ago. (Haven't checked the polarity on this new one, but I expect it to be the unchanged). The Viridians have built-in LEDs so you can see what state they are in.

One extra component was needed, that ecoharmony don't have on their their site, though it's shown in the circuit diagram and mentioned. This is a single pole Contactor, to isolate the Earth in case of PEN Loss. As all my other components are rated 40A (not sure about the Rolec Contactor, but is definitely 32A at least & shouldn't see > 32A ever) I wanted a 40A single pole Contactor. Garo do one, the "GK40 1NO 230V AC". Amazingly, I can only find one distributor online who stocks this, and they're in Ireland! All the other contactors seem to be 2 or 4 Pole, which is a waste of a pole, and probably more expensive than necessary. Whether you could split the Earth line and take it through 2 poles of a 2-Pole 20A contactor I don't know, but I feel this is risky as the poles are bound to open at microscopically different times, so one pole must in theory be left trying to carry a surge current of 40A at the same time as trying to kill the arc. Ok this is worst-case scenario, but that's the point, to cope with a worst-case.

Only modification to the Rolec case was to snap-off two green plates under the top waterproof lid that lets you get at the RCBO, as I put the new Contactor beside that clipped onto the standard rail, and lined the 2 items up to fit.

The EPC 2.0 comes as standard with a small Current Transformer (CT) with black & yellow twisted-wire leads, this gets the Earth wire to the car fed through it and does the PEN Loss testing. An optional extra is the RCM Residual Current Monitor which is a small box with 4 wires out, and a built-in CT; this gets the L & N wires to the car fed through it, so any imbalance means problems, current going where it shouldn't, and again a signal goes to the Viridian which shuts down the system. So now all 3 heavy-gauge wires to the car go through contactors, and all are isolated completely in case of an error. This comes with an excellent manual, and my wiring was exactly as per their supplied 230V diagram in section 6.3, they even label the terminals on the contactors & coils! Was no problem to fit this. Pics below show the new arrangement inside my Rolec, I have to say it's now a tangle of wires! But nothing's getting trapped as I close the lid (carefully!).

Prices of items (VAT included):
1 x Garo RCBO 1+N 40A char B 6kA Type A (RCBOGRB40)(A) = £ 22.02 in July 2017 (meteorelectrical.com similar today)
1 x Garo 40A Contactor 1 Pole 230V 1 Normally Open N/O AC/DC Coil Modular DIN Rail = £ 37.95 Nov 2020 (a1electrics.com, easier to search "GK40 1NO 230V AC" on eBay as payment easier, same shop.)
1 x Viridian EPC 2.0 EVSE controller & 6mA DC RCM kit (EPC20B10 + DCS6-01) = £184.80 (ecoharmony.co.uk)
+ a few short bits of wire for the new Contactor, and some wire-terminal crimps.

Total = call it £250 in round figures.

Rolec with new EPC 2.0 fitted. (BTW entire thing was isolated by small CU with Breaker & RCD both off, before you moan about the RCBO being on!)
View attachment 137589

Viridian EPC 2.0
View attachment 137590


PEN Loss CT, comes with EPC 2.0
View attachment 137593

DC Leakage Sensor / RCM Support module, located just above Rolec Contactor on LHS.
View attachment 137594

Garo Contactor on left, RCBO on right.
View attachment 137591

Rolec 32A Contactor
View attachment 137592

Rolec powered up, gently-pulsating blue Led visible through clear window.
View attachment 137595

Great post and nice job

Those Western Automation sensors are very accurate too when I've tested them. Just make sure your low voltage wires and we'll separated say by double insulation from the 230V AC.

 

[HandyAndy]

... Just make sure your low voltage wires and we'll separated say by double insulation from the 230V AC.

Thanks, good idea. I think I'll feed them through a length of shrink-wrap in that case, will also help protect against any abrasion if there's any vibration/movement/whatever going on. Won't do any harm to do the same for the existing CP & PP wires as well as the new CT ones, I guess...

 

[Myzopia]

Based on HandyAndy's success I carried out this same upgrade on two Rolec chargers (even wangled a small discount from EcoHarmony who sell all the kit and they seem to be a very helpful and professional company) - I chose to replace the Rolec contactor with a 2 pole 40A unit and used the same for my Earth disconnection contactor and as they are narrower they all fit on the DIN rail quite nicely with the DC monitoring module and the Earth CT tucked in at the top. There's no original Rolec equipment left at all now!

Since taking the picture I've also sourced JST connectors and DC/DC power regulators (buck convertors) that have allowed me to reduce the Viridian 12V supply down to 6V to drive the original Rolec LEDs and all works fine (they are the same polarity as the Rolec i.e. constant +ve supply and switched -ve for each colour). There is a slight design oversight in that the connetion for the outboard LEDs is on the inside of the Viridian module and they have not left a route out for the cables so I did have to drill a hole in the clip-on front cover. I hid the buck convertors in a terminal box from B&Q and I'm happy with the result (I actually also installed a second buck convertor in one of my Rolec chargers (both fit in the same B&Q box) to give me a 3.3V supply as I had a spare Tesla cable from a damaged UMC with the unlock button on the handle which needs this DC supply to function - it works fine pressing the button to open the charge port but once I'm plugged in pressing the button again does not release it so I'm back to the drawing board on that front).

JST connectors : 10PCS JST-XH Connector 2S 3S 4S 5S 6S Balance Extension: Amazon.co.uk: Electronics
Buck convertors : Valefod 8 Pack LM2596 DC to DC High Efficiency Voltage Regulator 3.0-40V to 1.5-35V Buck Converter DIY Power Supply Module: Amazon.co.uk: Business, Industry & Science
B&Q terminal box : B&Q Clear Terminal strip protection box | DIY at B&Q

 

[HandyAndy]

Nice job! How did you deal with the Rolec LED unit having the opposite polarity to the Viridian outputs? Did you dismantle it to separare out the contents? thought it looked a bit difficult to do that.

2nd point - I see you have a snapped pillar on LHS. I just happen to sell a Rolec Wallpod EVSE Charger Case Repair Kit on eBay which will mend this!
Unusual disclaimer - I have every financial interest in this!!

 

[goldtop]

Cool project. For those without a Rolec box, is there a type of outdoor wallbox that this could be built into?

I guess the hardest part would be the Type 2 socket (or tethered cable outlet).

 

[Jeremy Harris]

Cool project. For those without a Rolec box, is there a type of outdoor wallbox that this could be built into?

I guess the hardest part would be the Type 2 socket (or tethered cable outlet).

I built mine into a GRP reinforced plastic IP66 enclosure. Not too elegant, but it's a tough unit that's totally weatherproof (the switch is also an IP66 sealed unit:

Another option for a weatherproof enclosure is to use an empty caravan hook up box, like this: IP65 MCB, RCD Enclosure,Caravan Hook Up, consumer unit enclosure,adaptable box 660042416391 | eBay

 

[Myzopia]

Nice job! How did you deal with the Rolec LED unit having the opposite polarity to the Viridian outputs? Did you dismantle it to separare out the contents? thought it looked a bit difficult to do that.

2nd point - I see you have a snapped pillar on LHS. I just happen to sell a Rolec Wallpod EVSE Charger Case Repair Kit on eBay which will mend this!
Unusual disclaimer - I have every financial interest in this!!

I have seen that EBay listing but I've just got a long screw in that post and it seems to still have enough to bite on.

The Rolec LED polarity is the same as the Viridian its just the voltage that's different (well mine was anyway - they may be different versions of the Rolec controller) more photos below...

 

[freddym]

Cool project. For those without a Rolec box, is there a type of outdoor wallbox that this could be built into?

I guess the hardest part would be the Type 2 socket (or tethered cable outlet).

The best enclosure are the OEM Viridian charger enclosures, nuclear strike proof.

 

[HandyAndy]

Viridian at ecoharmony.co.uk and evbitz,uk sell all sorts of items for making your own EVSE, so sockets, cables,...

 

[Jeremy Harris]

The very best cable I've found is this stuff, sold by EVChargeKing: Charging cable - Single Phase - 32A - evChargeking

I have absolutely no connection with them, other than as a customer, but, having suffered from poorly manufactured cable (almost always from the Far East) including the truly dreadful Chinese stuff that Rolec use, that ties itself in knots internally, this European made stuff is like a breath of fresh air. It's got a smaller outside diameter, something that needs to be taken into account when sizing cable glands and choosing connector bushes, but the cable doesn't kink and is much stiffer than everything else I've seen, with the exception of the very heavy and stiff cable that Tesla use on the TWC.

My personal preference would be to steer well clear of Chinese cable, I've just seen too much of that stuff that's of dubious quality. Sadly, some UK suppliers (including one mentioned earlier) still sell the Chinese stuff - I got caught out a few weeks ago ordering some, thinking it would be British or European, only to find it's branded "Chang Zhou Painuo Electron" (anyone wants it I have a 5 or 6 metre coil they can have for free - I won't give it house room, and frankly I don't trust the spec).

On the flip side, everything I've bought from Ecoharmony has been of good quality, and I've built a few charge points using the Viridian controllers (including some from when they were still branded Mainpine) and never had the slightest issue with them. Of all the EVSEs that claim to have effective open PEN protection, the method used by the Mk2 Viridian EPC seems to be far and away the best. I'd already used the Western Automation DC tolerant earth leakage sensing module in a DIY charge point, and when I had a look at how the Viridian Mk 2 EPC combined this with voltage sensing and, most importantly, earth current sensing only in the CPC from the car charger, I'm reasonably convinced that this is as good an open PEN fault detection system as it's possible to get without using an earth electrode. It's not as safe, or cheap, as making the charge point a TT installation, but for an installation where an earth electrode isn't an option, it comes a pretty good second best.

On the topic of making up tethered cables, it's worth noting that a pretty hefty crimp tool is mandatory. Soldering the wires to the connector pins is wholly unnaceptible - the joints will fatigue and fail, possibly risking an internal short when this happens. I use a hydraulic crimp tool (anyone's welcome to borrow it if they are near enough to collect it, or I'll crimp up leads for free), but the ideal tool is probably something like a big Harting ratchet crimp tool, just because space is a bit restricted when the leads are fed through the inner part of the connector, and the Harting tool is a bit slimmer (and also a great deal more expensive!).

For anyone considering a home made charge point, or replacing the tethered cable on any other charge point, I'd recommend buying a ready made tethered cable. The price isn't a lot different (a 5m cable and and 32 A Type 2 connector costs ~£120 inc VAT etc, a ready made 5m 32 A cable and Type 2 connector costs ~£135 inc VAT etc), and for anyone with a Tesla there's an option to buy a ready made 5m 32 A single phase cable and connector assembly that includes a "Tesla button" (remotely opens the charge port flap and also terminates the charge and unlatches the Type 2 connector) for ~£178 (if anyone wants one of the latter, I have a spare, brand new and unused 5m one, I'm selling as I've sold my Tesla).

 

[goldtop]

Cool - thanks for sharing, guys. After getting the shocking (sic) quotes for a workplace charger installed (see other thread), I'm considering to get an electrician to put up a dumb tethered charger, and live with that for a few years. That or the Commando socket + semi-smart cable mentioned on the other thread. Time to think...

 

[Jeremy Harris]

Cool - thanks for sharing, guys. After getting the shocking (sic) quotes for a workplace charger installed (see other thread), I'm considering to get an electrician to put up a dumb tethered charger, and live with that for a few years. That or the Commando socket + semi-smart cable mentioned on the other thread. Time to think...

If getting a commando outlet installed it's worth bearing in mind that it will need exactly the same DC tolerant earth leakage protection and, if it's a PME installation, some form of open PEN fault detection and protection. BS7671:2018, amendment 1, Section 722, specifies what's required for any outlet used to charge an EV, so these safety requirements apply as much to a commando outlet as to any other charge point.

Given that some charge points now include both DC tolerant earth leakage protection and open PEN fault protection it may well be more cost effective to fit one of those. Doesn't need to be a "smart" one, if you're not claiming the OLEV grant. My personal view is that often the non-smart charge points are a better bet, in terms of reliability and simplicity.

 

[goldtop]

^ Thanks, that's a useful reality check.

Q: do all of the modules need to go inside the charge point (i.e. the box screwed to the outside wall)? Can some/many of them be mounted at the supply? This is what it'll be working from. Seems to be plenty of room:

 

[Mike Schooling]

^ Thanks, that's a useful reality check.

Q: do all of the modules need to go inside the charge point (i.e. the box screwed to the outside wall)? Can some/many of them be mounted at the supply? This is what it'll be working from. Seems to be plenty of room:

View attachment 141731

That's a 3 phase TN supply.

Assuming you will be charging outdoors, this method of PEN fault protection (described by the OP) is not compliant with 3 phase supplies.

You'll likely need either:

• To tt island each EVSE and manage sim contact risks manually.
• A 3 phase upstram protection device, e.g. Matt:e O-PEN.
• an EVSE that works under indent (iii) or (v), e.g. myenergi Zappi or Indra Smart PRO.

Sent from my SM-N976B using Tapatalk

 

[goldtop]

Thanks Mike.

• TT = earth rod at the charge point, AAUI, so that's out because it's a fully tarmaced area with unknown services below.
• O-PEN - looks super smart, but I don't think the O-PEN device itself is available separately from the box (so £495 to start).
• Will look at your Indra later today.

 

[DragonQ]

Very interesting post. Does anyone know if newer models are affected by the same issues as the OP's unit? I have a 2020 HomeSmart.

 

[Jeremy Harris]

Thanks Mike.

• TT = earth rod at the charge point, AAUI, so that's out because it's a fully tarmaced area with unknown services below.
• O-PEN - looks super smart, but I don't think the O-PEN device itself is available separately from the box (so £495 to start).
• Will look at your Indra later today.

The earth electrode can be anywhere that's reasonably close to where the car will be parked; it's the position of the car, not the charge point, that is key. It does need to be outside the zone of influence of other services, but generally a couple of metres is OK. For example, the detached garage supply that feeds the charge point I recently fitted to charge my wife's new car has an earth electrode that's just driven through a hole drilled in the garage concrete floor. I drilled a hole around 20mm diameter through the 150mm deep concrete, adjacent to a wall, then used a bolster to cut out a square recess above that to take one of the small plastic box earth pits (it's about 100mm square and 50mm deep).

I drove the earth electrode down though the hole into the ground beneath, tested it, then grouted in the box with a bit of mortar, so the lid almost flush with the floor. I've done much the same with putting electrodes in concrete and tarmac drives, pretty much every commercial building will have its earth electrode fitted like this, have a look around supermarkets, garages, etc and you will often spot the earth electrode pit set into a hardstanding somewhere (TT earthing is pretty much standard for commercial premises).

Personally, I'd not touch the matt-e device. I don't agree that it fully meets the requirements, as it only does voltage measurement, and there have been several reports that the cheap contactor they use can be noisy. The Viridian box is far and away the best, technically, but still second best to an earth electrode.

 

[Mike Schooling]

The earth electrode can be anywhere that's reasonably close to where the car will be parked; it's the position of the car, not the charge point, that is key. It does need to be outside the zone of influence of other services, but generally a couple of metres is OK. For example, the detached garage supply that feeds the charge point I recently fitted to charge my wife's new car has an earth electrode that's just driven through a hole drilled in the garage concrete floor. I drilled a hole around 20mm diameter through the 150mm deep concrete, adjacent to a wall, then used a bolster to cut out a square recess above that to take one of the small plastic box earth pits (it's about 100mm square and 50mm deep).

I drove the earth electrode down though the hole into the ground beneath, tested it, then grouted in the box with a bit of mortar, so the lid almost flush with the floor. I've done much the same with putting electrodes in concrete and tarmac drives, pretty much every commercial building will have its earth electrode fitted like this, have a look around supermarkets, garages, etc and you will often spot the earth electrode pit set into a hardstanding somewhere (TT earthing is pretty much standard for commercial premises).

Personally, I'd not touch the matt-e device. I don't agree that it fully meets the requirements, as it only does voltage measurement, and there have been several reports that the cheap contactor they use can be noisy. The Viridian box is far and away the best, technically, but still second best to an earth electrode.

To be clear. I was referring to the 3 phase matt:e device not their domestic indent (iv) device which would also be non compliant (and buzzy!).

Commercial EV Installations

Workplace EV charge point connection centres without earth rods

matt-e.co.uk

Sent from my SM-N976B using Tapatalk

 

[Jeremy Harris]

To be clear. I was referring to the 3 phase matt:e device not their domestic indent (iv) device which would also be non compliant (and buzzy!).

Commercial EV Installations

Workplace EV charge point connection centres without earth rods

matt-e.co.uk

Sent from my SM-N976B using Tapatalk

Sorry, crossed wires on my part! I hadn't realised the reference was to 3 phase. I agree, measuring interphase voltage should work OK on 3 phase, it's their approach to only measuring between L1 and N that I believe is flawed when it comes to reliably detecting a floating PEN fault on a single phase supply.