When to notify dno of car charger in domestic

Stephen Withnell said:

The DNO did some work a couple of weeks on our single phase, domestic supply, our property is looped off the semi next door.

If the cable comes from the pole to next door and my neighbours have a 100 A fuse, and I have a 100 A fuse, does that mean that the cable from the pole must be rated at 200 A?

I assume not on the grounds of diversity, but with large long loads, the assumption may no longer be valid.

CBSharpe said:

The maximum is 80A but 80A can take loads upto 100A for 4 hours within a 24 hour cycle for those who have small spikes for chargers or heat pumps. 

Just to be clear, that may be the DNO perspective, but it's not necessarily the same perspective in BS 7671, and if the DNO's cutout is used for overcurrent protection of any part of the consumer's equipment (e.g. tails), effectively this could limit the supply maximum demand (or more pertinently for what is becoming a common solution, import limitation, or load curtailment, setting) to 80 A.

By amendment I mean whatever upgrades are required to meet the maximum demand of the property after diversity has been applied. Some legacy cut outs and cables don’t facilitate 80A so we may need to do a cable overlay or cut out change or de-looping of the property once we have assessed the size of the loop and whether there are any low carbon technologies already on it. 

Looped supplies, the last I heard, said that you could have 1 LCT in a loop of 4, 2 in a loop of 3 and for some reason 1 in a loop of 2. Anything bigger than 4 and we would de-loop or any more than 1 in the scenarios mentioned we would also de-loop. 

I have since left that post to take up an engineering role in the same business but at the time of leaving, and I’m pretty sure it’s still company policy, but we no longer offer 100A on a single phase supply. The maximum is 80A but 80A can take loads upto 100A for 4 hours within a 24 hour cycle for those who have small spikes for chargers or heat pumps. 

CBSharpe advises that his DNO does not charge for single phase amendment needed at a property.

I am assuming that by "amendment" this includes upgrade of an existing cut-out and fuse?

Has anyone a list of DNOs who similarly do not charge?

Hi Graham,

The DNO did some work a couple of weeks on our single phase, domestic supply, our property is looped off the semi next door.  The DNO has fitted a new 100A main fuse and holder  (It was previously 100A, but decades old).  The reason for the DNO intervention was that the neighbour wanted an induction hob fitted and the electrician wasn't happy with the supply arrangements and triggered the visit from the DNO.

Are the DNO likely to want to de-loop the supply for the provision of an EC charger?    If the loop is fused at 100A, then surely that must indicate the loop has capacity for the EVCP.    The DNO connections team want me to make a formal application before the planners will comment.

I work for a DNO accepting chargers onto our network. All chargers need to come to us for either notification of installation or application for installation depending on whether it meets the criteria set out by the energy network association. 

Use the ENA website to download an application form and if you can tick all the relevant tick boxes for the charger then you can apply for notification of installation. Any box not able to be ticked comes to us for assessment.

Any single phase amendments needed at the property is now FOC at our DNO. Three phase dependent on network requirements.

Since the grants were reviewed there are far more contractors able to install and far less scrutiny on the quality of the job. It is likely that most contractors not previously on the OZEV scheme would be unaware of the COP and the DNO notification requirements. From what I can see, installing an EV point in domestic premises is looked upon in the same way as installing any other circuit. No concern about open PEN, RCD type, main protective bonding or maximum demand and certainly no worry about permission or notification.

Chris Pearson said:

So I can understand why some don't and 24Hour feels frustrated.

Yes, I've heard response times to requests can be lengthy (and even longer estimated time to upgrade if necessary) , and this is why a lot of companies instead of pre-notifying are load-curtailing so the MD < 60 A (where this is possible).

The frustration is not just domestic either. I think there are big challenges ahead.

Chris Pearson said:

63 A (or is that 60 A?)

That would depend on whether it's a BS 88-3 cartridge fuse (63 A is the preferred value) or a BS 1361 (60 A is the preferred value).

gkenyon said:

I guess if your MD isn't going to exceed your existing connection agreement, there would be no point in pre-notification?

FWIW, my original (SP) supply is on a 63 A (or is that 60 A?) fuse.

I do wonder how many people are aware of their connection agreement. I know my new one only because it was agreed (or imposed!) prior to connection.

Back to the OP: no harm in enquiring (as opposed to notifying) except that the answer may be "no" in which case the householder may regret asking. So I can understand why some don't and 24Hour feels frustrated.