Ratmeister
DIY
I've a 3 phase storage heater currently wired to the main fuse box in an office I have. The heater has 2 supplies/isolators, 1 for charging at night and 1 for the fan (this is live 24 hrs a day). The charging supply only comes live at night due to a dedicated timer installed on that circuit for the heater.
In the same office, we have a dedicated Economy 7 fuse box. This fuse box comes live when the timer from the electricity supplier turns it on at night. I have about 6 smaller storage heaters connected to this Economy 7 fuse box.
I would like to alter the wiring slightly to switch the 3 phase heater to use the Economy 7 fuse box to charge the heater at night like the other heaters (Fuse box is 3 phase). This would remove the dedicated timer and rely on the timer from the supplier to turn on the nightly supply as it does for the other heaters. The fan supply could then remain on the main fuse box to allow 24 hour power for it.
The reason I would like these changes is that it gives me more accurate sub metering for billing purposes and also means that the storage heater can never be charged on a peak time tariff accidentally.
The wiring diagram is attached as a photo. Can this be done? An Electrician had a look and said it can't be, it needs a dedicated timer and contactor and both supplies need to be on main fuse box and can't be split. Would like a second opinion though as I have hopes someone on this board can explain how it can be done!
In the same office, we have a dedicated Economy 7 fuse box. This fuse box comes live when the timer from the electricity supplier turns it on at night. I have about 6 smaller storage heaters connected to this Economy 7 fuse box.
I would like to alter the wiring slightly to switch the 3 phase heater to use the Economy 7 fuse box to charge the heater at night like the other heaters (Fuse box is 3 phase). This would remove the dedicated timer and rely on the timer from the supplier to turn on the nightly supply as it does for the other heaters. The fan supply could then remain on the main fuse box to allow 24 hour power for it.
The reason I would like these changes is that it gives me more accurate sub metering for billing purposes and also means that the storage heater can never be charged on a peak time tariff accidentally.
The wiring diagram is attached as a photo. Can this be done? An Electrician had a look and said it can't be, it needs a dedicated timer and contactor and both supplies need to be on main fuse box and can't be split. Would like a second opinion though as I have hopes someone on this board can explain how it can be done!
![[ElectriciansForums.net] 3 phase heater & Economy 7 wiring diagram question](https://electricians.s3.eu-west-1.amazonaws.com/data/attachments/74/74396-e24604fcaf03587bd55ec8dc07726909.jpg)
