Testing and Commissioning Archives - Basic Electrical Design

Commissioning Procedure For Bus Ducts.

April 28, 2019 basicelectricaldesign

Step by step Commissioning guidelines For Bus Ducts. Check the bus duct for physical damage and water ingress. Get it cleaned thoroughly. If a space heater is provided, ensure that there is adequate clearance between the heater wires and the main conductors. If necessary, dress the wires properly and securely. If a space heater is provided, test the operation and set the thermostat appropriately, based on the local ambient conditions. Perform megger test and, if it is an HT bus-duct, HV test. IF HV test is done, megger test should be repeated after…

Commissioning Procedures for Protection Relays On Site

April 27, 2018May 5, 2018 basicelectricaldesign

Pre commissioning check/Instruction of Protection Relays Refer to Siemens protection relays:- Check the relay model number (type number) is as per specifications. Note the serial no of the relay of the relay. Inspect the relay for signs of physical damage. 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. Test the relay as per the procedure for the given relay. Protection relays can be divided in to current operated ( eg- CDG…

Testing of Stability of Transformer Differential Scheme

April 25, 2018April 25, 2018 basicelectricaldesign

Guidelines of transformer differential stability check Transformer above 2 MVA are normally provided with differential protection scheme. The relay can be of static type(DTH31- Alsthom) or numerical type( 7 UT- Sag ) The relays have to be tested as per the procedure mentioned in manuals.The procedure mention below enables the testing engineer to confirm the correctness wiring. Expected short circuit current can be calculated from the % impedance of the transformer. e.g. Consider a transformer of 10 MVA, 132 KV /11 KV, % impedance – 13 % Calculated primary full load current…

Commissioning of isolators and earthing switches

April 22, 2018April 22, 2018 basicelectricaldesign

Guidelines of Commissioning of isolators Some of the important guidelines to be followed before energizing the isolators and earthing switches. For your reference, please find below the step by step process of commissioning of isolators: Isolators can be of the following types Centre break Double break Pantograph Operation of isolators can be motorized or manually operated. The nameplate details of an isolator consists of rated current, rated voltage, short circuit current rating, the auxiliary voltage required for operation etc. For a motorized isolator closing & opening is normally controlled by ‘close’,…

Commissioning Procedure for Electric HT Motor

April 21, 2018April 21, 2018 basicelectricaldesign

Quick Guidelines of Industrial Electric HT Motor Pre-Commissioning checks:- Check for the proper fixing motor on the foundation. Check that the motor can be easily turned over by hand. Check motor winding resistance on each phase; verify that they are equal. IR value and PI value of the motor to be checked. IR values and HV test on the cable to be performed. Check all the tripping and alarm signals from winding and bearing TRDs (through scanner if provided) Testing of ht motor protection relay and tripping of the circuit breaker…