Surge Protection for off peak DB too?

[spud1]

Hi guys,

So I have a domestic scenario where off peak E7 storage heating is installed.
Client has asked for a DB upgrade and has opted for surge protection.
Currently they have separate ON and OFF peak Wylex fuse boards tailed individually from the origin, the meter is 2 metres away.
If I installed surge protection in the replacement ON peak consumer unit ONLY, would that be deemed as sufficient protection for the off peak circuits too?

I think yes but I'm not certain.

My logic being that as the ON and OFF peak line and neutral tails are, when the economy 7 contactor is closed, connected in parallel to the metering equipment, any transient overvoltage voltage should take the path of least resistance through the surge protection device on the ON PEAK tails rather than present itself onto the OFF peak tails? Or is that just wishful thinking....?

 

[Strima]

Any possibility of a separate enclosure fed from source to cover both DB's?

 

[spud1]

Any possibility of a separate enclosure fed from source to cover both DB's?

Yes absolutely that is a possibility, the SPD would have to be at least 3 pole to enable both lines and N. But I was more interested in whether protecting at the ON peak DB would be sufficient protection for the OFF peak too.

 

[Strima]

Transient currents don’t care about surge protection and will go where the want. The circuits on the protected DB would be protected but the chances are the off peak would be screwed.