Isolator Pre-Commissioning Test Procedure

Purpose

This procedure is designed to conduct a systematic series of pre-commissioning tests on isolators to make sure the equipment’s functionality and health.

Scope

The pre-commissioning test for isolators is addressed in this procedure, as follows:

• Insulation Resistance Test
• Contact Resistance Test
• Infrared Test of Isolator Motor Winding

Responsibility

Unit Heads/Regional Managers

• Planning and scheduling of activities to ensure the successful execution of the project 
• Identifying and addressing significant health and safety hazards 
• Meeting all legal & statutory requirements
• Assist the safety team in conducting the safety training and audit at the sites. 
• Ensure that all safety rules & regulations are adhered to at the work sites.

Site Engineers

• Site engineers responsibilities include reporting any health and safety concerns at work sites to the regional manager, unit head, or safety team.
• Coordinate with customers to obtain and return work permits. 
• Communicate work content and hazards to working groups through toolbox meetings before each day’s start. 
• Implement proactive measures to reduce accidents.
• Report incidents in detail. 
• Use proper PPE. 
• Maintain job quality without compromising safety. 
• “Stop Work” for significant safety violations.

Safety Engineers

• Safety engineers responsibilities include ensuring the application of occupational health and safety instructions and procedures.
• Communicate safety rules, regulations, and practices to site engineers, regional managers, and unit heads. – Follow up on audit non-conformances and assist regional managers/unit heads in taking corrective and preventive action.
• Report and investigate incidents and near misses to top management.
• Organize frequent training programs and raise awareness among site engineers and regional managers.
• Conduct daily toolbox discussion sessions to ensure workers are aware of workplace hazards.
• Ensure the use of PPE and safety equipment at work sites. 
• Report any health and safety issues to the unit head or regional managers. – Provide basic first aid facilities on-site.
• Ensure no harmful acts are undertaken on any site.
• Eliminating harmful conditions on-site promptly. 
• Issuing safety challans for violations.

Work Activity 

Pre-Testing Checks

• Examine the operating status of the ELCB (30 mA).
• Inspect power cable insulation for equipment.
• Ensure that adequate earthing & rubber matting are available on the jobsite.
• Utilize calibrated testing equipment & report calibration results to engineers.
• Check the technician’s insulation hand tools.
• Check test leads for insulation damage.
• Make sure suitable PPE is accessible at the site.

Equipment Required

For IR Test

• Insulation Tester (500 and 5000 V)
• Test Leads.
• Insulated Hand Tools

For Contact Resistance Measurement Test

• This package includes a contact resistance meter with test leads ranging from 200µΩ to 2000µΩ for measuring motor winding resistance. 
• A multimeter with test leads.

For Motor Insulation Resistance Test

• Insulation resistance tester (500/5000V)/megger
• Test leads.

Test Procedure

Insulation Resistance (IR) Test for Isolators

• Obtain the work permit from the customer.
• Test equipment for zero energy before starting work.
• Place isolators in close positions.
• Connect the megger’s positive lead to the isolator pole. 
• Connect the earth lead to the ground. 
• Turn on the megger & press the test button to record the data.
• Connect positive lead to one pole & negative lead to another while isolator is open. 
• Turn ON the megger. 
• Inject the voltage & record the readings.

Motor Winding IR Test (with 500V Megger)

IR Test from Phase to Phase

• Connect the megger to the motor terminals “U1 & V1”. 
• Turn on the megger and click the test button to record the data.
• Discharge potential from “U1 & V1” terminal to earth. 
• Turn off the megger. 
• Repeat for remaining terminals (V1 & W1 and W1 & U1).

IR Test between Phases and Earth

• Shorten the motor terminals (U2, V2, and W2). 
• Connect the megger to the motor terminal “U1” and Earth. 
• Turn on the megger and click the test button to record the data.
• Discharge potential from “U1” terminal to earth. 
• Turn off the megger. 
• Repeat for other terminals (V1 and W1).

Contact Resistance Measurement Test

• Obtain work permit from customer.
• Test equipment for zero energy before starting work.
• Connect CRM kit to Isolators’ moving and fixed contacts when they are closed.
• To test the CRM kit, turn it on and click the test button. 
• Record the readings.
• Connect the CRM kit to the connectors of the isolators when they are open.
• Turn on the CRM kit, test the press button, and record the readings.

Control Measures

• Testing engineers provide OCP (Over Current Protection) for IR & CRM for Isolators.
• Make sure PTW system in place for the specific bay.
• Make sure all equipment is turned off. 
• No unauthorized individuals should be allowed to enter the testing area. 
• Use warning tape to barricade the area. 
• Use a normal insulated ladder for heights less than 2 meters.
• Inspect ladders before work. 
• Keep both feet below the third rung from the top. 
• Use one hand on the ladder at all times. 
• Proper supervision, including job-specific toolbox meetings and barricades.
• To ensure safety, utilize calibrated equipment, insulated hand tools, avoid power cable joints, and supply via ELCB. 
• Avoid working alone and wear proper insulated gloves.

Final Check & Restoration of Work 

• Disconnect the temporary supply & remove barricades. 
• Remove any unsecured tools from the area. 
• Maintain a tidy and clean environment after leaving.

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