Overloaded electric supply

[Scorpion]

Hi, I have a MG 5EV on the motability scheme which also comes with a free home charging unit supplied and fitted by BP PULSE. After sending in all the relevant photos of the drive, chosen mounting position for the charger and pictures of the meter cupboard and consumer board they have said I'm overloading my 100 amp supply if i have a home charge unit. Apparently because i have a washing machine, tumble dryer, dishwasher, microwave etc etc they have to check with national power to see if i can have a charger. Anybody else come up against this issue, there calculating that I'm using 96 amps without the charger.

 

[Jake]

Hi, I have a MG 5EV on the motability scheme which also comes with a free home charging unit supplied and fitted by BP PULSE. After sending in all the relevant photos of the drive, chosen mounting position for the charger and pictures of the meter cupboard and consumer board they have said I'm overloading my 100 amp supply if i have a home charge unit. Apparently because i have a washing machine, tumble dryer, dishwasher, microwave etc etc they have to check with national power to see if i can have a charger. Anybody else come up against this issue, there calculating that I'm using 96 amps without the charger.

I have a 100 amp supply fuse. BP Pulse installed a 2nd 7kWh wall box last year saying I just crept within the maximum limit. Like you I have the usual white goods including 2 x 32 amp cooker points and the original 7kWh wall box installed about 5 years ago. I don't have a power shower point though which I believe can be very highly rated. Could this possibly be why you are already rated at 96 amps?

 

[greentangerine]

If you want to while away a few hours, look up diversity calculations on the web and get even more confused.

One of the advantages of the Zappi (and the OpenEVSE I use - although I don't need to use that facility) is that you can throttle the charge automatically based on house load - there's a video on YT of an electrician installing the Zappi in a house for precisely this reason and configuring the max house load to 96A. Doesn't help resolve your situation unfortunately.

 

[ARealHuman]

I had something like this - my electricity supply was shared with our neighbour, so after our charger was installed, our local supplier came along and split our dual supply into two supplies to each property which involved digging up our driveway. Perhaps something similar could help your situation?

 

[Scorpion]

I have a 100 amp supply fuse. BP Pulse installed a 2nd 7kWh wall box last year saying I just crept within the maximum limit. Like you I have the usual white goods including 2 x 32 amp cooker points and the original 7kWh wall box installed about 5 years ago. I don't have a power shower point though which I believe can be very highly rated. Could this possibly be why you are already rated at 96 amps?

Good to hear that you've managed to get even a second EV charge point, none of the showers are power showers and normally for load calculations these are not included as they are considered to be a temporary load for say 10 minutes. I only have one 32 amp cooker point, we don't use the emersion heater ever. Don't understand how we can be rated so high already.

 

[Scorpion]

If you want to while away a few hours, look up diversity calculations on the web and get even more confused.

One of the advantages of the Zappi (and the OpenEVSE I use - although I don't need to use that facility) is that you can throttle the charge automatically based on house load - there's a video on YT of an electrician installing the Zappi in a house for precisely this reason and configuring the max house load to 96A. Doesn't help resolve your situation unfortunately.

Yay more maths that when calculated will still mean very little to me, unfortunately i don't get a free choice of installer only what's offered. Good to know there is a calculation available if it's needed

 

[greentangerine]

There is essentially no diversity applied to instantaneous water heaters aka electric showers. There's a BS code for this but a useful table can be seen here.

The YT video which shows how a Zappi copes with this circumstance (plus other charger installation gotchas) is here and definitely worth a watch - in fact this guy's and JW's theory videos are to be recommended.

However, I think most electricians use their common-sense in working such things out.

 

[Scorpion]

I had something like this - my electricity supply was shared with our neighbour, so after our charger was installed, our local supplier came along and split our dual supply into two supplies to each property which involved digging up our driveway. Perhaps something similar could help your situation?

My supply is separate already but i hope something like common sense can intervene as i don't intend to be running all my household electrical items when I'm charging the car in the early hours

 

[Scorpion]

There is essentially no diversity applied to instantaneous water heaters aka electric showers. There's a BS code for this but a useful table can be seen here.

The YT video which shows how a Zappi copes with this circumstance (plus other charger installation gotchas) is here and definitely worth a watch - in fact this guy's and JW's theory videos are to be recommended.

However, I think most electricians use their common-sense in working such things out.

Thanks, i will take a look at the videos later today, I'm sure common sense should pay more of a part in this.

 

[greentangerine]

My maximum load since I've had a charger/BEV has been just short of 13kW - that's during the Go cheap period with the battery pile taking 3kW, the charger 7kW and presumably both dishwashers, the washing machine and the dryer all on the go (pun intended).

 

[SimonomiS]

My maximum load since I've had a charger/BEV has been just short of 13kW - that's during the Go cheap period with the battery pile taking 3kW, the charger 7kW and presumably both dishwashers, the washing machine and the dryer all on the go (pun intended).

Nice! That's around 60A at 220v so way short of 100A

 

[chowbenter]

The BP Pulse guys gave me a list as long as your arm what needed upgrading to my 60amp shared loop electricity set up / supply, The DNO are due to upgrade our electricity supply on the 23rd/24th February which will mean digging up my lawns. This has been going on since the 2nd November last year due to all manner of delays.

 

[BigEVuser]

Thanks, i will take a look at the videos later today, I'm sure common sense should pay more of a part in this.

Sorpion..... Unless you have electric storage heating then your unit use will only be about 10 Kwhs per day... That equates to about 20 Amps at anyone time...I do appreciate that it is higher when you switch on your electric shower or cooker but overall they are on for short times... Most 3 bed houses which have non electric heating can take the additonal 7kW .... unless you have a looped system from next door
Please get someone in who knows what they are doing

 

[Scorpion]

The BP Pulse guys gave me a list as long as your arm what needed upgrading to my 60amp shared loop electricity set up / supply, The DNO are due to upgrade our electricity supply on the 23rd/24th February which will mean digging up my lawns. This has been going on since the 2nd November last year due to all manner of delays.

Sounds like BP PULSE have given you the run around as well, is this through motability or choice

 

[chowbenter]

It was through choice well MG suggesting them to me. The same DNO team that came out to access our situation were working in the next street on a friends house which has exactly the same shared loop electricity supply as us & I rang him the other night to ask how he went on with the upgrade, He said it was cancelled due to one of the residents in one of the other houses testing positive for covid, I'm just hoping it's not going to affect our upgrade appointment as ours was pushed back from last month for the exact same reason withn one of our neighbours having a positive test.

 

[Scorpion]

It was through choice well MG suggesting them to me. The same DNO team that came out to access our situation were working in the next street on a friends house which has exactly the same shared loop electricity supply as us & I rang him the other night to ask how he went on with the upgrade, He said it was cancelled due to one of the residents in one of the other houses testing positive for covid, I'm just hoping it's not going to affect our upgrade appointment as ours was pushed back from last month for the exact same reason withn one of our neighbours having a positive test.

Okay, well i hope it all goes well for you

 

[Ranger]

I also have all the normal white goods on a 100amp main fuse. I have a 7kwh rolec and a zappi charging my Leaf and MG5 while the washer is on using Octopus Go. it seems a little odd.