Maximum Demand / ENA / EV Help!

Sparkingchip:

Red dye in domestic electric might make lighting a nice rosy colour.

Just don't let them catch you using any of the red electrons to charge your car!

D4G:

Thanks for the input, although we did go off at a slight tangent ?

Well, we have answered the question and now we are just nattering. ?


So what is the proportion of discussion in here about EVs? 25%?

D4G:

Hello all,


This evenings issue relates to an EV charger install.

The supply cut out is labelled 60/80 amp so I called the DNO and asked if this could be uprated to 100 amp.

They have sent me the ENA EV application form which asks for the Maximum Demand including the new equipment.

The problem I have is the existing circuits are:


32A - 7.2 kW shower 

40A - 8.2 kW shower

32A - Ring main

32A - 7.9 kw cooker

6A - lighting

6A - lighting

6A - security


Additional 32A for EV charger


So even with diversity I'm way over 100A, obviously in reality the diversity calculations are not appropriate as the client has never blown the cut out.

The smaller shower is not currently in use although they want to replace it for another one, I have told them this may not be possible.

The EV charger will have load management but I still need to put a figure on the ENA form....


Help appriciated :)

The customer will not like it, but it’s the second electric shower that doesn’t even work that really messes the sums up, so they need to be told that it cannot be replaced like for like without a priority switch.


If the installation needs load management to get the DNO to sign off the application then so be it.

https://www.meteorelectrical.com/distribution-control/consumer-units-accessories-1/garo-priority-shower-board-choose-priority.html

AncientMariner:

I'm thinking here of it likely being first come, first served until the capacity runs out...

Sparkingchip:

The customer will not like it, but it’s the second electric shower that doesn’t even work that really messes the sums up, so they need to be told that it cannot be replaced like for like without a priority switch.


If the installation needs load management to get the DNO to sign off the application then so be it.

https://www.meteorelectrical.com/distribution-control/consumer-units-accessories-1/garo-priority-shower-board-choose-priority.html

I have told them that the replacement shower should be a mixer type or have a priority switch installed.  I'm sure if they ask someone else they will just fit it being as the second shower was fitted by someone in the first place!


If the cut out is 60/80 amp as suggested, by the label then upgrading to 100A and by adding the EVSE with load management the system will be better off anyway ?


I just need to suggest the MD is 81 amps or more.

Chris Pearson:

D4G:

Thanks for the input, although we did go off at a slight tangent ?

Well, we have answered the question and now we are just nattering. ?


So what is the proportion of discussion in here about EVs? 25%?

Its all educational, maybe...?