UNDERGROUND CABLE SITE PRE-COMMISSIONING AND COMMISSIONING PROCEDURE

Typical Megger Test Procedure of Power Cable

How Carryout the Underground Power Cable Project Pre-commissioning and Commissioning?

The service provider shall be responsible for the safe and efficient setting to work of the whole plant and equipment. The methods adopted shall be to the approval of the Engineer or his representative on Site and shall be in accordance with any safety and permit regulations in force by the Employer on the Site.

 

Key Test Equipment and Tools Required at Site:

Up to 10 kV multiple range megger tester;

Digital earth tester;

DC 10 kV sheath tester;

DC high voltage test set;

Pole Rescue Kit;

Switchboard Rescue kit;

Confined Space Monitoring and Rescue equipment;

Roadway warning signs;

Barricading;

Worksite communication equipment (e.g. 2-way radio);

An insulated operating stick and tool head;

Insulating Gloves applicable to the task;

Dry chemical fire extinguisher, etc.

Documentation Required for Pre-commissioning and Commissioning

HV cable pre-commissioning and commissioning Inspection form;

DC 10 kV sheath insulation test report;

High voltage test report;

Copper core megger test report;

Capacitance test report;

Earth electrode resistance test report for joint bay;

All test reports for each joint bay.

 

Schedule for Pre-commissioning Test

At least two months before commencing the commissioning of any plant or equipment, the service provider shall submit for approval fully comprehensive schedules of pre-commissioning checks as applicable to each item of the plant and equipment provided. 


These schedules shall then be used during pre-commissioning as a guide to the methods to be followed and to record the actual activities carried out with the appropriate date, together with details of all work yet to be completed, variations, and modifications to design conditions.
The schedules shall be countersigned by the Engineer’s Representative as necessary. If during the performance of the pre-commissioning checks the Engineers representative considers that additional tests are necessary to prove the system or plant the Service-provider shall perform such additional tests to the Engineer’s satisfaction.

 

In addition, the service provider is to submit the schedules to the Engineer’s representative proforma test sheets (to be used by the service provider during testing and commissioning) for all tests he proposes to carry out and those required by the Engineer’s Representative.

Each activity on the schedules, when completed to the satisfaction of the Engineer’s Representative, shall be signed and dated by the Service Provider. 

 

Schedule for Commissioning and Its Procedure

The service provider shall also submit for approval schedules of commissioning procedures that proposes to follow when bringing into service groups of plant items during the commissioning period. 

These schedules shall detail the tests necessary to ensure the complete and satisfactory commissioning of each section of the plant and shall detail all operational limitations. 

The schedules shall be used during commissioning which shall only commence when the relevant pre-commissioning check schedules have been completed.

 

Each activity on the commissioning procedure schedules when completed to the satisfaction of the Engineer’s Representative, shall be signed and dated by the Service Provider and shall be countersigned by the Engineer’s Representative as necessary.

The commissioning procedures shall ensure that the commissioning of any section of the Works does not interrupt the normal commercial operation of any previously commissioned section(s) and/or existing facilities.

 

21 days prior to commencing commissioning checks the Service-provider is to agree with the Engineer’s representative the method and sequence of performing the commissioning tests. 

Following agreement the Service-provider shall submit a detailed program indicating the testing sequence to permit advance notice to be given to the Employer in order that the Employer’s representatives may also become witness testing if so desired.

 

When the commissioning of each section of the work is complete the service provider shall carry out such preliminary tests as are necessary to establish that the plant is functioning correctly and efficiently and shall make any adjustments required.

 

The service provider is to supply all test equipment, tools chemicals, lubricating oils and greases, and other materials required for the aforementioned operations.

 

Site Supervisory Staff for Commissioning Test

During the commissioning and subsequent testing of any item of the plant, the service provider is to provide the services of any special supervisory staff necessary for the purpose of ensuring proper commissioning and the satisfactory completion of all tests. The kind of such services is deemed to be part of the tendered for Erection of Plant.

Skilled Manpower required as:

Electrical Fitter or Cable joiner;
Competent Assistant;
Safety supervisor or observer required.

Commissioning of Modified Circuits of Line

Where the scope of works has included the diversion, relocation, or variation of any existing circuit the service provider is deemed to have included for all pre-commissioning checks on existing equipment. 

Where this work includes overhead line or cable circuits the Service-provider is responsible for carrying out full pre-commissioning and on-load checks at the remote end of the circuit including the injection testing and re-setting of relays or other controlling devices if required.

 

All and any such work associated with the re-commissioning of existing equipment is deemed to be included in the contract.

 

Test Equipment for Carry Out the Pre-commissioning and Commissioning Test

HV Cable Commissioning Equipment

The service provider is responsible for providing all equipment, tools power supply, etc. necessary to carry out all tests on site. 

Following the award of the contract the successful service provider shall submit a detailed schedule of the test equipment that should be used and intends to provide for carrying out this portion of the work. 

If the Engineer requires additional or alternative test equipment to be provided to enable full site testing to be performed in accordance with the requirements of the specification the Service Provider shall supply such equipment as a part of the contract.

 

Preliminary Steps and Safety Induction for Commissioning Test at Site

It’s necessary to follow the local and international safety rules to carry out the pre-commissioning and commissioning test at the site. Need to ensure the safety notice to the working force and the public in the working zone.

 

Ensure appropriate construction and operational drawings are on hand during carrying out the pre-commissioning and commissioning test;

 

Before testing confirm physical check first that cables are well dedicated in position, then apply correct methods to positively identify the cable to be tested, including ensuring that circuit and cable numbers are securely attached;

 

Ensure that the associated switchgear is in a safe position and operational nameplates are in secured condition;

 

Ensure test equipment is well prepared to carry, check the equipment's next maintenance and calibration date is not expired;

 

Ensure all persons required to use test equipment are competent in its operation;

 

Ensure PPE for all as where necessary, then assign adequate staffing resources with required competencies to safely complete tasks, confirm electrically safe for electrical work;

 

Use roadway warning signs and barricading by warning tape to control vehicle and pedestrian traffic around the working area and relevant exclusion zones around live parts.