Maximum Demand / ENA / EV Help!

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

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