Commissioning Procedures for Protection Relays On Site

Commissioning Procedures for Protection Relays

Pre commissioning check/Instruction of Protection Relays

Refer to Siemens protection relays:-

  1. Check the relay model number (type number) is as per specifications. Note the serial no of the relay of the relay.
  2. Inspect the relay for signs of physical damage.
  3. Check that any series resistors, where applicable, have been installed e.g. for CTMM relays a series resistor is required in the power circuit, depending on the supply voltage.
  4. Test the relay as per the procedure for the given relay.

Protection relays can be divided in to current operated ( eg- CDG series, & SJ600, bus differential, transformer differential etc), Voltage operated (VAGM, VD, 7RW 600), relays requiring voltage & current inputs (CDV, 7SJ531, 7SA etc).

Testing instruction for CDG relays.

  1. Test to be done in accordance with commissioning instruction for above relays for non-directional & directional inverse time over current and earth fault relay with MRI 220C.
  2. Reading obtained during testing should be recorded in commissioning test.
  3. For permissible variations in current please refer of commission manual.
  4. The above mentioned commissioning instructions & commissioning test report should be referred to by commissioning engineers where these relays are to be tested & commissioned.
  5. Where necessary depending on customer’s equipment & manual consent on Test/Formats etc. suitable test procedure may be adopted after documenting the consent.
  6. Manufactures test recommendations shall be final in case of any disagreement / ambiguity.