I have a borewell with a 3-phase submersible pump that I want to control with a water level controller (when the overhead tank is empty, it should start the motor and when the tank is full it should stop the pump, automatically).
On the advice of the sales staff, I purchased a controller rated for 415 volt which (according to the staff) was the most suitable for my 3 phase pump. (Technical info of the GIC Water Level Controller here - PDF file).
Now, I am confused as to how to connect the mains to the controller. The circuit diagram for my requirement shows -
- Neutral being connected to A2 terminal and Line to A1 and 15 terminal in the controller.
But since my controller is rated for 415 volts, should I instead connect the 3 Lines (RYB of 3-phase) individually to the A2, A1 and 15 terminal, as otherwise the single phase (neutral and line) will provide only 230 volts?
FYI: Single phase supply in my country is 230 volts and three phase is 240 / 415 volts at 50 hz.
(The service engineer who can clarify my doubts is not reachable for a few days and hence my post here).
Page 186 of the technical sheet of the controller has this connection diagram:
which clearly shows that the input supply should be 110v / 240v / 400 volt (+ or - 20%) depending on what the controller is rated for. As I said before, the sales person insisted that the 415v rated controller is what I need for a 3-phase pump.
The controller has this printed on its side:
This input supply of 415 volt is the source of my confusion as residential single phase supply in my country is 230 volts only. (And that is why I assumed that I have to use more than one phase as input to provide the 415v).
- Am I misunderstanding something very obvious or did the sales person give the wrong advise and I should have got the 240v rated controller?
Since some of you have asked about the motor controller - the unit has a contactor, relay and single phasing protection relay (SPPR - SZ5). Circuit Diagram:
I was advised to remove the loop between D1 and D2, and connect terminal 18 (of the water level controller) to D1 and connect terminal 16 (of the water level controller) to D2. This would ensure the water level controller would automatically start or stop the pump through the motor controller.