Electromechanical & Static Relays
- Inspection, servicing, testing, and calibration of protective and auxiliary relays including minor repairs.
- Physical inspection, cleaning of relays, wiring check and tightness of connections. Free movement of rotating parts, mechanically / electrically operated flags and contacts. Checks on trip isolating contacts, shorting of plug bridges.
- Insulation resistance test.
- Checking of electrical operation indicators, internal auxiliary elements, DC auxiliary, and master trip relays for pick-up and drop-off values and drain current in case of Static, Microprocessor and Numerical relays including the resistance of the coil.
- Secondary injection tests on IDMTL – current – volt relay, instantaneous current volt relay, time delay relay, motor protection relay, differential relay and all another relay as per IS and manufacturers tests recommendation and commissioning manuals.
- Visual inspection of any damage to relay.
- Visual inspection of wiring and tightness of connections.
- Visual inspection of PCB cards for any dry solder or abnormality.
- Cleaning of relay body for proper insulation level.
- Insulation resistance measurement between all terminal and body and between various circuits.
- Checking for proper operation.
- Measurement of Drain current (mA)
- Checking for electrical LED indicator.
- Checking of Binary Input/output, signaling relay, command relay and LED programming in case of 7SJ600 / 7RW600 relay.
- Checking of Relay Settings values for proper operation of the relay.
- Checking of relay characteristics as per IS and manufacturers tests recommendation and commissioning manuals.
Power & Protection System
- System study of plant distribution for adequate protection and perfection.
- Fault level calculation and short circuit studies.
- Protection relay co-ordination studies for grading of overcurrent and earthfault relays and unit protection relay settings for motor, transformer and generator.
The Power System Studies shall be carried out by the latest release of ETAP (Electrical Transiant Analyser Program) modules developed by OTI-USA and KLG system Ltd., which is extremely versatile for solving majority of Power System Analysis Problems.
Protection System Refurbishing
- Restricted Earth Fault ( REF ) protection scheme for transformer.
- Transformer and generator differential protection scheme.
- Busbar differential protection scheme.
- Pilot wire protection scheme for feeders.
- Synchronising scheme for parallel operation of the generator with Grid.
- Load Shedding Schemes for Grid islanding.
- Modernisation and retrofitting of ageing protective relays.
- Modification of H.T. Panel having time limit shunt fuse into protective relays.