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Discussion Starter #1
Hoping this might be relatively quick.
Planning to get a 7kW Podpoint charger installed on the outside of the garage (c 14m from the meter/consumer unit in the house). Can't get car any closer to house than that.
Garage has secondary consumer unit with:
  • 16A RCD from main consumer unit
  • Underground SWA cable (Draka) which is BS5467 3-core, 20mm ext diameter marked as "3 x 10" and "600/1000V"
  • Existing RCDs are 6A and 2x16A - have lights/sockets and two small sewage/water pumps running off these.

If my understanding is correct the cable should be adequate for a 7kW charger plus existing load but I'll need a new RCD on the main consumer unit and possibly a new consumer unit in the garage. Am I close?

Massive thanks, good to have so much expertise available on here!
Pete.
 

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Renault ZOE R135 ZE50 GTLine July 2020 (Sold: R90 ZE40 i Dynamic Nav June 2017)
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Assuming that the 3x10 means three 10mm2 conductors you have plenty of current capacity. Voltage Drop Calculator | TLC Electrical says that it should cope with about 50A if underground.

I'd certainly put a consumer unit in the garage, with appropriate MCB/RCD/RCBO for each circuit.

It might be an idea to connect direct to the incoming supply after the meter (and isolation switch, if there is one) depending on where your DNO box and main consumer unit are. See A cautionary tale of severe electrical fire for a discussion following a fire probably caused by a loose connection on a tail into a consumer unit.

I'd fit an isolation switch if there isn't one. I'd want to take an electrician's advice on if and how to protect the SWA cable.
 

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Chances are that Podpoint will want to take the power directly from the meter and bypass your consumer unit completely. The good news is that Podpoint, unlike some others installers, count 15 metres as a standard install so you shouldn't have to pay any extra. 16 amp is only suitable for a 3.5 kW chargepoint, not for 7 kW, that requires 32 amps. You cannot put anything else (e.g. your garage lights) on the same circuit.
 

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Hoping this might be relatively quick.
Planning to get a 7kW Podpoint charger installed on the outside of the garage (c 14m from the meter/consumer unit in the house). Can't get car any closer to house than that.
Garage has secondary consumer unit with:
  • 16A RCD from main consumer unit
  • Underground SWA cable (Draka) which is BS5467 3-core, 20mm ext diameter marked as "3 x 10" and "600/1000V"
  • Existing RCDs are 6A and 2x16A - have lights/sockets and two small sewage/water pumps running off these.
If my understanding is correct the cable should be adequate for a 7kW charger plus existing load but I'll need a new RCD on the main consumer unit and possibly a new consumer unit in the garage. Am I close?

Massive thanks, good to have so much expertise available on here!
Pete.
Pete, based on your description, you most probably do have a 3 x 10mm2 XLPE SWA cable feeding your garage.

The most expensive part of any 7kW charger installation, would be installing a feed to the garage, or in your case NOT reusing what you already have.

For this reason, I would directly involve a local electrician. ENTIRELY forget about using a national charging company. They will either suggest that a new cable is required or will severely under design the installation wrt to RCD discrimination and load management etc.

Tell the electrician you want the EVSE installed to BS7671 18th edition and amendments, that you want the cable size to be confirmed. Ask him to make a detailed report on the condition of the existing feed and protection arrangements for that garage supply and ensure there are no weak links in terms of underrated or old switches, loose connections (see "precautionary tail" recent posting in this website where a forum contributor had a major fire in his garage).

regards
 

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The wall unit takes 30 amps plus you have other loads fed from the garage so you are going to need, say, a 50 amp feed from the main consumer unit to the garage then a 32 amp mcb plus rcd in the garage. There is the issue of discrimination between the wall unit breaker and the feed from the main consumer unit to the garage (depends how important the other garage loads are). Far simpler to feed the wall unit direct from the meter if practical. Either way you need the installer to do an assessment first.
 

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The wall unit takes 30 amps plus you have other loads fed from the garage so you are going to need, say, a 50 amp feed from the main consumer unit to the garage then a 32 amp mcb plus rcd in the garage. There is the issue of discrimination between the wall unit breaker and the feed from the main consumer unit to the garage (depends how important the other garage loads are). Far simpler to feed the wall unit direct from the meter if practical. Either way you need the installer to do an assessment first.
Very true. Designing a safe installation that can reuse the existing cable is possible but totally out with the remit of the national charging companies. avoid them for this installation.
 

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Discussion Starter #7
Thanks all. Very helpful. This install is supposed to be happening as part of a lease car deal, making it virtually free.

Gary: although Podpoint might count a 15m install as standard, they will only run the cable along a wall and not underground, so wouldn't be able to install the charger on the garage wall (detached from house) if running directly from meter. Could install on outside wall of house but then would need 6m charging lead to reach the car and this would be a trip hazard (which is against PodPoints standard installation checklist thing).

Thanks Freddym for the detailed advice. Sounds like this might be the safest and best option all round, and won't cost much in the big scheme of things, assuming Podpoint are happy for someone else to do the install...?

Will speak to PodPoint and see what's feasible.
 

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Lease?

Not mentioned in original post.

It's your house and your safety.

Don't confuse getting something for free with the above.

Read the near miss / garage fire post
 

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Pete your best off posting pics of both CU. Pod can and do come from garage CU’S. If you’ve got a 10mm cable feeding your garage pod will upgrade your mcb feeding it (if it needs its).
 

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Your setup is similar to mine for cabling. I'm 21.2 cable metres away.

My previous EO installers replaced the fusing in the garage with 32a RCD, put a new consumer unit in and wound down the charger to I think 28A because there was a possibility of exceeding the 32a on the charger with the other stuff in the garage or if used other ad hoc electrical appliances.

My new Zappi installers have changed my RCD due to possible issues with DC leakage.

16a is a low rating in the garage TBH and i'd think you'd need a proper electrician's survey 1st.
 

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Podpoint are proper electrons, jeeze they aren't sending Oliver twist.

Every pod had a CT clamp, you can run it on any cable. 10mm is plenty.
 

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Podpoint are proper electrons, jeeze they aren't sending Oliver twist.

Every pod had a CT clamp, you can run it on any cable. 10mm is plenty.
Read it again. No ones calling out Pod-Point. Just a ‘proper’ electricians survey, which happened with both my installs, BEFORE they turn up to do an install and the OP finds they cannot install a system & get the full power he was expecting.

16a RCD suggests there may be an issue and extra cost.


Sent from my iPhone using Tapatalk
 

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Podpoint ask for photos, the op has some good clear info. It doesn't need a electrician to be paid to survey it.

Podpoint will survey via photos and install in the garage, if it needs further works they'll catch it first from the photos or when a installer turns up. If something hasnt been picked up by the photos the installer will list to the customer what needs doing.

A 16amp rcd would indicate the customers made a error and it's a mcb, that's why I asked for photos.
 

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Discussion Starter #14
Thanks Jrtev for the alternative viewpoint re PodPoint installation. Since you asked for photos...

Main CU in the house. Number 6 is the breaker for the garage supply (labelled Garage + Waste Pumps) - B16.

134631


This is the secondary CU in the garage - the supply cable is just visible at the bottom, with the size I previously indicated. Currently supplies lights, a pair of sockets (rarely used), and a small sewage pump. (The water pump isn't in use at all.)
134630


Grateful for any other insights if that's helpful. My lease deal has been a bit slow coming through but going to explain the setup to PodPoint once it's confirmed and see what they say. If there's any mention of needing a new cable or if they sound uncertain I'll get a local electrician involved. I'd welcome other viewpoints on whether PodPoint are likely to be able to facilitate a safe install on this.
 

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Given its on a B16, you will need to survey the run from the CU to the garage. For instance they may have run the 10mm underground, but not brought it all the way to the consumer unit, and instead gone to a junction box and dropped down to a smaller cable. If your certain the 10mm cable comes all the way into the consumer unit, then you need to ascertain the availability of 50A breakers for that board. Its also old, and on a single RCD, so you might want to consider some upgrades. At the simplest. removing the existing 10mm SWA from the consumer unit, and feeding it from a 50A switchfuse would sort out the supply end without touching the rest of the board.

The 10mm cable in the ground is certainly big enough.

Out in your garage, again its an old board, but assuming you can get a breaker, you can install a B32 and run the charger from there. If there isnt a spare way, you will want to fit a larger CU in the garage.

I suspect getting podpoint to agree to all of that work is perhaps stretching things, but i guess you can ask. Potentially you might have to get some of it done yourself (eg the switchfuse and new CU in the garage) and then get them to complete the install.
 

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Go here:-


This is a list of electricians that can install and supply if needed any of the major EV Chargers. They will also be able to do all the other checks and upgrades required, plus make sure all is safe. This is easier than trying to deal with the Charger Supplier.

Assuming the 10mm does run from the Consumer unit to the Garage Board, I would guess they can upgrade the Consumer unit breaker to a 45A. Then if you are not using the pumps in the garage then change that breaker to a 32A too and just come form that.

However, as always get a qualified electrician to do the survey and work so it's all certified - don't trust a forum ;)
 

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Type A rcb - tick
Size of cable feeding garage db - Tick
Mcb at house db - needs to be b40
Garage db - no spare ways, problem as there isn't any circuits you can combine.
So you'd need a new garage db.
 

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you need to ascertain the availability of 50A breakers for that board. Its also old,
I have the same board - the installers used a Wylex RCBO for the charger about 4 years ago. When I had an extension a couple of years ago, the electricians converted the lighting circuit to an RCBO that matches the board, so they must still be available. They also said that all the devices should be from the same manufacturer as the board but that may be more opinion than a documented requirement.
 

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I have the same board - the installers used a Wylex RCBO for the charger about 4 years ago. When I had an extension a couple of years ago, the electricians converted the lighting circuit to an RCBO that matches the board, so they must still be available. They also said that all the devices should be from the same manufacturer as the board but that may be more opinion than a documented requirement.
Eaton make them now.
 

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They also said that all the devices should be from the same manufacturer as the board but that may be more opinion than a documented requirement.
yeah its one of those greyish areas i think. The boards type-approval requires it to be fitted with the original manufacturers breakers. Other ones might fit, but the bus-bars arent standardised so its potentially a bad idea to mix and match.
 
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