Control Circuit , Control Supply, Power Circuit, Power Supply Definition:
Control supply is nothing but a separate power supply to operate or control the power circuits using control circuit. Here control circuit means the auxiliary circuit which is made with contactors, NO & NC switches, protecting relays, MCB etc.. i.e in a starters DOL or star/delta, we use contactor, when the contactor holds the power goes to the load. To hold the contactor, we have to give the electrical supply to the contactor coil. That supply is called control supply. The control supply voltage level is depending on the contactor coils typically,
- 440Volts used in agriculture starter
- 230 Volts used in industrial DOL or Star delta starter
- 110 Volts used in heavy hoist and crane application
- 24 Volts used in PLC /DCS control system.
- 5 Volts used in Microprocessor and electronics equipment.
Note: Some time the control supply will be taken from the power supply with the help of control transformer.
What is Power supply?
The three phase or single phase raw supply will be directly given to the load with the help of control circuits. Power circuit contains Circuit breakers, isolator, MCCB, MPCB, Busbars, VFD etc. The power supply and control supply have different control accessories. They never interfere with each other.