CHANGE OVER PROCEDURE FROM WESCO SUPPLY TO DG SUPPLY AND VICE VERSA

ALWAYS REMEMBER:

Wesco power supply and DG power supply are two different supply with different frequencies, phase and voltages. These two should not be mixed; otherwise a circulating current will flow in the circuit and burn the whole system.

DG -1 belongs to FEEDER-1 and DG-2 belongs to FEEDER-2 of Panel.

DG-1 connected to DG Incomer-1 and DG-2 connected to DG Incomer-2(630A MCCB).

Transformer-1 incoming connected to ACB-1 and Transformer-2 to ACB-2.

The Bus coupler divides the main bus into two different feeders.

PROCEDURE TO START UP THE DG AND CHANGE OVER FROM GRID TO DG POWER:

1. Ensure the grid indicators are OFF.2. Bus coupler should be OFF.3. Suppose I want to start the DG-1.4. First of all ensure the DG-1 Incomer MCCB (630A) is in OFF position.5. Go to ACB-1 and make the ACB-1 OPENED. Take out the CASTELL Lock

and keep the key in your pocket.6. Go to the DG and first check the 800A Load MCCB inside the Canopy of

DG is in OFF position and the emergency stop is released.7. Check the oil level in oil tank, radiator coolant level, Battery DC

voltages. 8. Go to the Manual control panel on front of DG and make the SS1

Switch ON i.e. the DC ON. After making ON the DC the electronic controller in AMF blinks and after few seconds they will OFF.

9. DG has 3 modes manual (M), automatic (A), Test (T).10. Always operate the DG in (M) mode that is manual. In this position

press the Green START button .The DG will start .Wait for few seconds, so that the DG will attain its speed and builds voltages.

11.Make the Load MCCB (800A) ON. Power will flow to DG Incomer-1.12. Go to the Panel room and ON the DG-1 Incomer (630A) MCCB.The R,

Y, B indicators of ACB-1 will glow. Now the Feeder-1 is charged with DG power supply. Checks the voltages and if it is OK then give Loads.

Similar procedure should be adopted for DG-2.

PROCEDURE FOR STOPPING THE DG POWER SUPPLY AND CHANGEOVER FROM DG to GRID POWER.

1- First ensure that the Grid indicators glow and WESCO power came.2- Disconnect the major loads on DG.3- Make the DG Incomer OFF (630A) MCCB.4- Go to the DG and make the Load MCCB (800A) inside DG OFF. Let the

DG to run in no-load for 5minutes.5- In the mean time come to the control room and put the CASTELL key

inside ACB and make the ACB CLOSED. The R, Y, B indicators again glow.

6- Switch on the loads.7- Come to the DG and stop the DG by pressing the RED button STOP on

the manual DG control panel. OFF the DC ON SS1 switch.

I understood the above procedures for changeover and can operate the system safely.

Name Designation Signature