EXPEL PROSYS             

         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 resistance of coil.
• Secondary injection tests on IDMTL – current – volt relay, instantaneous current volt relay, time delay relay, motor protection relay, differential relay and all other relay as per IS and manufacturers tests recommendation and commissioning manuals.

         NUMERICAL RELAYS   

• Visual inspection for 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 relay.
• Checking of relay characteristics as per IS and manufacturers tests recommendation and commissioning manuals.

• 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.

• 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 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.

1. Well established SERVICE CENTRE of having full fledged testing equipment facility, expert man power and large stock of recommended proprietary spare parts to undertake repairing and calibration of general auxiliary and special relays.

OUTDOOR SWITCHYARD

Pre-commissioning tests for outdoor switchyard equipments (complete package) like power and distribution transformer, circuit breaker, CT-PT-NGR-NGT, lightning arrestor, insulator, isolator, earthing installations, relay and control panels, HT busduct and cables and other electrical equipment as per the design and requirement of system.

DISTRIBUTION SYSTEM

Pre-commissioning tests for electrical distribution system like HT Switchgears, LT Switchgear, Motor Control Centres, Distribution Transformer, HT/LT busduct, HT cable, HT/LT Motor, Battery, Battery Charger and other electrical equipment like TCE / DCL / MNDASTUR / KIRLOSKAR / UDHE / PDIL / EIL

CAPTIVE POWER PLANT

Pre-commissioning tests of turbo-generator set alongwith auxiliaries (complete Package ) like generator, generator transformer, busduct with CT-PT-NGR-NGT, relay and control panels and other electrical equipments as per the design and specification for consultants like TCE/DCL /DESIN and other reputed consultants in the field of Power Generation

 CONULTANCY

• Basic design and detail engineering for Electrical Power Distribution System.
• Preparation of technical specifications for capital intensive items.
• Invitation of bids and techno-commercial analysis.
• Preparation of lay-out drawings, inter-connection drawings, single line diagram, earthing and lighting layouts, cable schedule and lay-out, control and protection schematics.
• Stage and final inspection of electrical equipment for meeting guaranteed technical performance.

PROTECTION SYSTEM STUDY

• Study of existing protection system of plant with suggestions and renovations for plant                          betterment for optimum selection of protective relays.
• Execution on turnkey basis for renovation and revamping switchgears, protective relays and Protective schemes based on comments of the Protection System Study Report.

FAULT  LEVEL CALCULATIONS AND SHORT CIRCUIT STUDIES

• For verification of authenticity of existing switchgear ratings as per the system operating        conditions of the plant.
• Fault level calculations can form a guideline for feasibility of existing switchgear for further expansion programmes.

RELAY CO-ORDINATION AND RELAY SETTINGS

• To achieve proper grading of overcurrent relays and to avoid frequent mal-operation problems if any.
• It also comments on the installed overcurrent and earthfault relays for various protection applications and suggest correct protective relay for particular application.

DESIGN AND DETAIL ENGINEERING OF PROTECTIVE RELAYING SCHEMES

• Restricted Earth Fault (REF) protection scheme for Transformers.
• Transformer and Generator Differential Protection schemes.
• Busbar Differential Protection.
• Protective Relaying Scheme for Generator as well as for parallel operation of Generator with Grid or parallel operation of Generators.
• Load Shedding Schemes for prevention of the collapse of in-plant generation under overload condition.