I have a house which has the strangest electrics ever - converted from 3 phase. Originally, it used a three phase board, but lighting circuit, power circuits etc were random - and highly dangerous, because I could have sockets on one phase and lights on another in the same room.
I had a sparky do his best to sort it out - we now have one phase for downstairs, and one for upstairs, with the third not being used - and lots of warning labels. However, I have one issue which I cannot sort out.
I use a thermal store powered from solid fuel, with an oil boiler as a boost, which has an overheat stat. This will turn on the heating if the store gets too hot, and this sits on one phase. I also have a tank stat that governs the temperature of the thermal store - and because the boiler is downstairs, it sits on the other phase - again, lots of warning labels. It will turn on to keep the thermal store at the right temperature.
The problem is that when the tank "dumps" because the solid fuel Raeburn is being efficient (ie the overheat stat cuts in), the returning cold water then turns the boiler on, which I do not want. I cannot run the stats in series, because they are on different phases. So what I need is to be able to safely switch the boiler out of the circuit from the overheat stat using the NC contact, so it wont fire if the overheat switches to its NO position. This means I need a relay, which I can hide our f harms way, which will take a feed form one phase and turn the switch on or off, but providing a switched output for a separate phase to control the boiler. Clearly, this phase isolation must be foolproof - anyone know of such a thing before I contact my sparks for advice?
Thanks
I had a sparky do his best to sort it out - we now have one phase for downstairs, and one for upstairs, with the third not being used - and lots of warning labels. However, I have one issue which I cannot sort out.
I use a thermal store powered from solid fuel, with an oil boiler as a boost, which has an overheat stat. This will turn on the heating if the store gets too hot, and this sits on one phase. I also have a tank stat that governs the temperature of the thermal store - and because the boiler is downstairs, it sits on the other phase - again, lots of warning labels. It will turn on to keep the thermal store at the right temperature.
The problem is that when the tank "dumps" because the solid fuel Raeburn is being efficient (ie the overheat stat cuts in), the returning cold water then turns the boiler on, which I do not want. I cannot run the stats in series, because they are on different phases. So what I need is to be able to safely switch the boiler out of the circuit from the overheat stat using the NC contact, so it wont fire if the overheat switches to its NO position. This means I need a relay, which I can hide our f harms way, which will take a feed form one phase and turn the switch on or off, but providing a switched output for a separate phase to control the boiler. Clearly, this phase isolation must be foolproof - anyone know of such a thing before I contact my sparks for advice?
Thanks