erection , testing & commissioning of isolators

8/10/2019 Erection , Testing & Commissioning of Isolators

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Erection , Testing &Commissioning of

Isolators


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ISOLATORS TESTING &

COMMISSIONING

Objectives

To ensure the completeness of theequipment before energisation.

To rectify the defects identified duringthe testing.

To ensure reliable trouble free operation

of the isolators in all respects.To facilitate the charging clearance from

the statutory authority.


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ISOLATORS - TESTING

The testing procedures for isolatorsare classified as given below.

General checks

Electrical Motor checks

Operational checks

IR Value test

Contact Resistance measurement

Checking of interlocks


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ISOLATORSGENERAL

CHECKS

Equipment is free from all visible defectson physical inspection

Support structures, marshalling box has

been provided with two earthing pads All nuts and bolts are tightened as per the

specified torque

Equipment erection is complete in allrespects as per the approved drawing


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ISOLATORSGENERAL

CHECKS

Leveling and alignment of structureand base frame

Control box/marshalling box is freefrom any physical defects

Tightness of nuts and bolts ofterminal connectors

Auxiliary contacts and relays havebeen cleaned and free from dust


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ISOLATORSGENERAL

CHECKS

Corona rings are provided andproperly fixed

Cable termination and tightness

External cabling completed in allrespects

All the cable identification tags

provided and all cores are providedwith identification ferules at M.B

All moving parts are lubricated


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ISOLATORSGENERAL

CHECKS

Freeness of manual operation

Greasing has been made on the maincontacts according to manufacturers

specificationFunctional checking of auxiliary

contacts for indications and

interlocksErection completion certificate along

with list of outstanding activities


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ISOLATORSGENERAL

CHECKS

All spare wires are terminated at theterminal blocks

Earth switch connected to earththrough braided wires.


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ISOLATORS CHECKS ON

ELECTRICAL MOTOR

IR value of the motor windingbetween phase to ground for all thethree phases.


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ISOLATOROPERATIONAL

CHECKS

Operate the isolator and record themotor current

Operation of isolator fromlocal/remote

Measurement of operating time.

Auxiliary contacts checking bothunder close and open condition

Checking of control circuit


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ISOLATORS INSULATION

RESISTANCE TEST

Isolator close condition

Between male side to ground andfemale side to ground

Isolator open condition

Between male side to ground andfemale side to ground

Between male side to female side


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ISOLATORS OTHER CHECKS

Contact resistance measurement

Checking of interlocks

Final documentation and approval ofthe test results.


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Thankyou

erection , testing & commissioning of isolators

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