EV Charger

[Tomosmorris94]

I have just installed my first EV Charger yesterday. I have installed using a 6mm twin from the non RCD side of the consumer unit on a 32a type b MCB. The length of run is around 5 metres and is contained in 20mm round conduit.

The charger I have fitted is a Rolec with a built in type A 30mA RCBO. I have installed an earth rod below the charger as I was told EV chargers can rely on the earth of a TNC-S system.

Upon testing j had a reading of 347 ohms on my Rod and 24.8ms on my RCD. my question is, would this be sufficient as it is protected by a 30mA RCBO therefore the maximum reading permittable is 1667ohms or am I wrong and does it have to be below 200ohms?? 50volts (touch voltage / 0.03 = 1666.66.

Thanks guys! Go easy, this is my first post!

 

[hasel5]

Needs to be under 200 ohms mate and if guy has a Zoe under 100 ohms

 

[Tomosmorris94]

Needs to be under 200 ohms mate and if guy has a Zoe under 100 ohms

He has an i3. Would you suggest banging another rod in then??

 

[hasel5]

You will need to get it below 200 at least

 

[pc1966]

He has an i3. Would you suggest banging another rod in then??

Is it the sort of rod that you can use a joining piece and add another length to it to bang in?

Generally a deeper rod is more stable against frost or drought changes than the equivalent of two shallow ones. That is the reason for the 200 ohms mentioned in 18th Table 41.5 (also citing 542.2.4) even though a 30mA RCD is theoretically OK with 1667 ohms.

 

[Tomosmorris94]

Is it the sort of rod that you can use a joining piece and add another length to it to bang in?

Generally a deeper rod is more stable against frost or drought changes than the equivalent of two shallow ones. That is the reason for the 200 ohms mentioned in 18th Table 41.5 (also citing 542.2.4) even though a 30mA RCD is theoretically OK with 1667 ohms.

Hi mate. No it is not one you can add an extension onto it ?. I read up in the regs regarding the 1667ohms if protected by a 30ma RCD. So would this reading of 347ohms be sufficient??

 

[mattg4321]

I wouldn’t be happy with it personally. Get a couple of 5/8 rods that you can join and whack them in. If that doesn’t get it significantly lower then go with a couple more 8 feet away.

 

[jackhammerJIM]

I have just installed my first EV Charger yesterday. I have installed using a 6mm twin from the non RCD side of the consumer unit on a 32a type b MCB. The length of run is around 5 metres and is contained in 20mm round conduit.

The charger I have fitted is a Rolec with a built in type A 30mA RCBO. I have installed an earth rod below the charger as I was told EV chargers can rely on the earth of a TNC-S system.

Upon testing j had a reading of 347 ohms on my Rod and 24.8ms on my RCD. my question is, would this be sufficient as it is protected by a 30mA RCBO therefore the maximum reading permittable is 1667ohms or am I wrong and does it have to be below 200ohms?? 50volts (touch voltage / 0.03 = 1666.66.

Thanks guys! Go easy, this is my first post!

I would not be happy with that reading . You should be attempting to get the reading as low as possible within a budget . This week we installed a similar setup with a 5/8s rod achieving 40 ohms . Last week we used 2 and got down to 20 ohms . Considering a rod and clamp is around £15 its hardly breaking the bank .

 

[Tomosmorris94]

I would not be happy with that reading . You should be attempting to get the reading as low as possible within a budget . This week we installed a similar setup with a 5/8s rod achieving 40 ohms . Last week we used 2 and got down to 20 ohms . Considering a rod and clamp is around £15 its hardly breaking the bank .

Cheers mate. Not that it's breaking the bank, just that it's in a hell of an awkward location. Gas and electric income within a couple of foot as well as 3 drains ?? I think I will just bang another rod in to be on the safe side but just hoping I don't hit anything!

 

[pc1966]

If you already have a rod in and know that particular place is safe, then put in a longer one in its place, maybe using a joining section so each section is manageable.

When I recently put in some 2m x M16 threaded stainless rod for earthing I used a 1m long SDS drill to get down the 1st metre before driving/screwing the rods in - that might help you get a bit deeper with the 5/8" = 16mm style of jointed rod.

If you put in a 2nd rod very close it will make little difference to the Ra value, you really want to be a rod's length away, or ideally two rod's length or more if paralleling rods.

 

[jackhammerJIM]

Cheers mate. Not that it's breaking the bank, just that it's in a hell of an awkward location. Gas and electric income within a couple of foot as well as 3 drains ?? I think I will just bang another rod in to be on the safe side but just hoping I don't hit anything!

Next time you look at an EV job if rodding is going to be a nightmare order a PEN fault relay and you wont have to use an earth rod .

 

[Tomosmorris94]

Next time you look at an EV job if rodding is going to be a nightmare order a PEN fault relay and you wont have to use an earth rod .

Cheers mate. Where would you get a pen fault relay from, how much are they and how would you install them?

 

[pc1966]

Cheers mate. Where would you get a pen fault relay from, how much are they and how would you install them?

Here are some examples:
https://www.cef.co.uk/catalogue/cat...]=wh_321347&sort=price_inclusive_vat.sort_asc
You might find it cheaper elsewhere like your local wholesaler, of course...

 

[hasel5]

Another option is fit a unit with a pen device fitted

 

[jackhammerJIM]

Cheers mate. Where would you get a pen fault relay from, how much are they and how would you install them?

Rolec make one i think they are around £110 plus vat . Comes in a 4 way db with 40amp rcbo included .

Also the zappi chargers have them inbuilt as standard and im sure a few other makes also .

 

[Gavin John Hyde]

I have just installed my first EV Charger yesterday. I have installed using a 6mm twin from the non RCD side of the consumer unit on a 32a type b MCB. The length of run is around 5 metres and is contained in 20mm round conduit.

The charger I have fitted is a Rolec with a built in type A 30mA RCBO. I have installed an earth rod below the charger as I was told EV chargers can rely on the earth of a TNC-S system.

Upon testing j had a reading of 347 ohms on my Rod and 24.8ms on my RCD. my question is, would this be sufficient as it is protected by a 30mA RCBO therefore the maximum reading permittable is 1667ohms or am I wrong and does it have to be below 200ohms?? 50volts (touch voltage / 0.03 = 1666.66.

Thanks guys! Go easy, this is my first post!

Tidy install with the conduit etc Not a fan of Rolec units myself as the quality is not there, if getting into the EV game start with some other brands. for £60 more you can get a zappi and the hub if going down olev route from the main suppliers and dont need an earth rod or upfront RCD. so much better in terms of quality and features.

Personally I wouldn.t be happy with a reading that high on an earth rod, If ground conditions permit I would look to get it in a lot deeper (use an sds attachment to drive it in ) or add additional rods. if not possible then the Matt: devices or the Garo alternative would be my go to device.

As mentioned some Renault EVs throw a tantrum on anything over 100 ohms. so bear this in mind.

The EV game is getting quite strict now on risk assessments and pre works surveys, NAPIT will soon be looking to inspect an ev charger install on annual assessments for those involved in the sector, have heard rumours NICEIC will be following suit, if you install chargers then they will ask to see one on the annual assessment either instead of or in addition to other work. as a lot of people are installing them with no regards for the condition of the existing install or risk assessments. OLEV are now asking for additional documents and wont be long before they ask for the pre install site survey to be documented and submitted along with DNO forms etc. I am all for it as I have seen some truly horrific installs, In one case

 

[HappyHippyDad]

I have just installed my first EV Charger yesterday. I have installed using a 6mm twin from the non RCD side of the consumer unit on a 32a type b MCB. The length of run is around 5 metres and is contained in 20mm round conduit.

The charger I have fitted is a Rolec with a built in type A 30mA RCBO. I have installed an earth rod below the charger as I was told EV chargers can rely on the earth of a TNC-S system.

Upon testing j had a reading of 347 ohms on my Rod and 24.8ms on my RCD. my question is, would this be sufficient as it is protected by a 30mA RCBO therefore the maximum reading permittable is 1667ohms or am I wrong and does it have to be below 200ohms?? 50volts (touch voltage / 0.03 = 1666.66.

Thanks guys! Go easy, this is my first post!

Hi Tomos. Can I ask if this is PME? You have said you have installed an earth rod because EV charges can rely on the earth of a TNCS which i dont quite understand. Did you mean 'couldn't rely' on earth of the TNCS?

Also, where have you actually terminated the earth cable you have installed. In the charging unit? If so, wouldn't that be classed as utilising note (ii) of regulation 722.411.4.1 which means you would have to get the Ra much much lower (in reality you would not be able to get it low enough without multiple earth rods as it needs to be around 1ohm).

 

[Doomed]

Look at Pod Point chargers in future - no rods needed

 

[Tomosmorris94]

Tidy install with the conduit etc Not a fan of Rolec units myself as the quality is not there, if getting into the EV game start with some other brands. for £60 more you can get a zappi and the hub if going down olev route from the main suppliers and dont need an earth rod or upfront RCD. so much better in terms of quality and features.

Personally I wouldn.t be happy with a reading that high on an earth rod, If ground conditions permit I would look to get it in a lot deeper (use an sds attachment to drive it in ) or add additional rods. if not possible then the Matt: devices or the Garo alternative would be my go to device.

As mentioned some Renault EVs throw a tantrum on anything over 100 ohms. so bear this in mind.

The EV game is getting quite strict now on risk assessments and pre works surveys, NAPIT will soon be looking to inspect an ev charger install on annual assessments for those involved in the sector, have heard rumours NICEIC will be following suit, if you install chargers then they will ask to see one on the annual assessment either instead of or in addition to other work. as a lot of people are installing them with no regards for the condition of the existing install or risk assessments. OLEV are now asking for additional documents and wont be long before they ask for the pre install site survey to be documented and submitted along with DNO forms etc. I am all for it as I have seen some truly horrific installs, In one case

Thanks mate! I think I will be putting another rod in, with a threaded end so I can attach another rod to drive it down deeper. I will get the reading down to below 200ohms! The car being charged is a BMW i3 ?

I have been made aware of rolec chargers not being the best on the market, but this one was supplied by the customer.

Thank you for your feedback mate. I will let you know how I get on ?

 

[Tomosmorris94]

Hi Tomos. Can I ask if this is PME? You have said you have installed an earth rod because EV charges can rely on the earth of a TNCS which i dont quite understand. Did you mean 'couldn't rely' on earth of the TNCS?

Also, where have you actually terminated the earth cable you have installed. In the charging unit? If so, wouldn't that be classed as utilising note (ii) of regulation 722.411.4.1 which means you would have to get the Ra much much lower (in reality you would not be able to get it low enough without multiple earth rods as it needs to be around 1ohm).

Hi mate. Yes I was meant to put cant rely on the earth of a TNCS system. I have terminated the earth cable from the earth rod to the earthing terminal within the car charger. The earth coming from the installation i have put in a Wago but connected the earth at the house end so the supply cable is protected.