1 SCOPE.
2 REFERENCE DOCUMENTS.
3 DUTIES AND RESPONSIBILITIES.
4 PRIOR TO TEST ACTMTY.
5 TEST EQUIPMENT SAFETY PRECAUTION.
6 OPERATION.
7 TOOLS AND EQUIPMENT.
8 INSPECTION.
Test Procedure for MV Cable DC HiPot Testing
SCOPE
This test procedure describes the work method for Medium Voltage Cable DC High Potential testing which will be carried out in Solar Combined Cycle Power Plant Project.
This method was prepared as guideline for effective enforcement of verifying integrity of medium voltage cable after installation and before final termination. Supervising technician has to determine the feasibility of this document in consideration with the approved cable schedule, actual site condition and manufacturer’s specified instructions.
2 REFERENCE DOCUMENTS
a) NET A – Inter National Electrical Testing Association.
b) Manual Operating Instruction (HiPot Test equipment).
c) Approved Issued for Construction Drawing.
d) Cable Schedule.
3 DUTIES AND RESPONSIBILITIES
Site Manager
Determine all requirements needed in order to comply with contractual
requirements and safety standards.
Construction Manager –
Lead all construction activities and enforce strict adherence to all
project requirements.
Electrical Superintendent Ensure that work once started is carried out as planned and
that the applicable standards are complied with. Check working methods and precautions to
be taken by the supervisors/foreman before commencing work.
Field Engineer – Ensure that all related works are carried out in accordance with approved
Issued for Construction drawings, specifications, schedule, quality and safety. Report to Construction Manager.
QC Inspector — Shall be responsible for conduction surveillance and inspection duties for
work and ensuring quality compliance and efficient recording and reporting of results if required. He shall review all relevant documents, material confonnance certificates and non
conformance reports. Prepares Request for Site Inspection.
Safety Officer — Ensure that HSE plan is being implemented and monitored. Ensure that
preventive measure are applied during continuity and insulation resistance test
Technician —
Ensure that proper procedure is initiated during test activity. He shall adhere
to Safety requirements at all times. He shall perform work to meet the Quality output.
Reports to Field Supervisor for output of the task performed.
4 PRIOR TO TEST ACTIVITY
a) Prior to any test performed, all the concerned personnel and departments will be informed thru RSI (Request for Site Inspection). Necessary work permit will be
acquired prior to execution of work.
b) All safety measures to be observed and proper barricade and safety sign will be
installed around the area of the equipment subject for testing. For long cables, both
ends should have a watchman with 2-way radios ( or other means of communication
device such as bravo phone).
c) Valid Calibration Certificate from Third Party approved by client must be ready for
reference verification.
d) Drawings, specifications and data sheets must also be ready for reference during the
test.
e) All Test forms/check list must be in accordance with the approved QA/QC
procedure.
) Testing procedure will be in accordance with the equipment sequence of operation,
system and loops functions.
g) Test shall be performed at de-energize condition. Ensure that cable is properly
supported and spaced away from conducting materials (i.e. adjacent equipment,
metallic part or other conductive material)
h) DC High potential test shall be
performed after it passes the insulation resistance
test.
i) Only qualified person will perform the test. Refer to manufacturer’s manual for safety procedures.
5 TEST EQUIPMENT SAFETY PRECAUTION
SAFETY PRECAUTION
DC HIGH VOLT AGE TEST EQUIPMENT CAN BE LETHAL IF USED
IMPROPERLY.
IT MUST BE OPERA TED ONLY BY TRAINED AND AUTHORIZED
PERSONNEL IN ACCORDANCE WITH ALL LOCAL SAFETY
REGULATIONS.
PLEASE PAY ATTENTION TO THE INSTRUCTION IN THIS PROCEDURE
AND THE EQUIPMENT’S OPERA TING MANUAL.
6 OPERATION
a) Check that test equipment is in good working condition; ensure that the input voltage
to the test is regulated.
b) Check test set and test lead at testing voltage level. Properly prepare the cable for testing; the cable will be tested after stress relief device was installed. Clearances will be observed at cable ends and to adjacent equipment prior to test.
c) High voltage line of Hi-pot equipment will be connected at phase to be tested. Phases which are not under test will remain grounded at both ends.
d) Test voltage shall be in accordance to manufacturer’s specification or as approved in the project specification. High potential test value will be applied in an equal increment until maximum test voltage is reached.
e) No increment shall exceed the voltage rating of the cable. DC leakage current at each step will be recorded after a constant stabilization time is consistent with system charging current. (Step voltage and maximum time and voltage test will follow the approved inspection and test checklist for DC hi-pot test).
f) As an acceptance result, step voltage should reasonably linear for the graphic plots of
leakage current versus step voltage at each increment. Capacitive and absorption
current should decrease continually until steady state leakage is approached for the
graphic plots for leakage current versus time at the final test voltage. All test result
shall be recorded.
g) Discharging after High Potential Test; At Hi-pot test equipment where automatic
discharging was initiated, always presume that the tested core is still under full
voltage load. Use a grounded discharge stick to completely remove stored electrical
charge after testing a cable core. Perform insulation resistance test after Hi-pot test
and record the result
Note:_For specific operation and use of HI-pot test equipment please refer to equipment’s
manual instructions
7 TOOLS AND EQUIPMENT
Standard Electrician’s Toolbox (plier, spanner, screw driver etc.)
DC High Potential Tester
Insulation Resistance Tester (Megger), Multi-meter (VOM)
Ground Discharge Rod
HV Insulation Tape, HV gloves
PPE (complete wear)
8 INSPECTION
Request for Site Inspection on DC
Hi-pot test will be coordinated by QA/QC Inspector,
who will implement the inspection program and notify all parties involved in advance of
the scheduled dates of inspection to enable them to participate. Relevant records shall be
signed by all the required parties and originals kept by Site QA/QC Department.
Any test equipment or tool will have a valid calibration certificate to comply with the
quality requirements
Step by Step Guide of the work plan
Explain in detail the steps that must be taken to ensure that the task is carried out safely (include drawing and sketches where required, include pre commencement of work activities and the work itself in a chronological manner)
A. Verify IFC drawings availability
B. Verify Documents for QC material receiving inspection
C. Preparation of tools and test equipment
D. Preparation of Cable cores
E. Insulation Resistance Testing
E. DC Hi-Pot Testing
G. Discharging
A. Preparation of tools and test equipment (Ensure pennit to work must be obtain, prior to start the activity. Conduct toolbox talk prior to the task to
be done. Wearing of PPE to all personnel. All tools and equipment is in good condition.
Careful handling of tools and test equipment)
B. Preparation or Cable (Arrangement of cable and careful handling, personnel must use PPE and when using Portable
ladder it must be 4:1 slope and one person holding to secured the ladder. use Full Body Harness 100% tie off when using scaffolding. Firm support of cable)
C. IR Cable testing Before and After Hi-Pot (Task Supervisor must organized the preparation and set-up the area to ensure Unauthorized personnel will keep away from the test area test will be performed to check the integrity of the cable.
Wearing appropriate PPE shall follow the agreed instruction and safety procedure initiated with their supervisor. Area
must be cleared with proper barricade with signage. Standby man must strictly monitor the area. Test equipment is in good
condition and has a valid calibration certificate)
D. Hi-Pot Testing (Perform test on cable core for I5 mins, refer to manufacturer’s recommendation for test voltage and procedure. only authorized person must be on the testing activity and ensure proper communication and coordination prior to the certain test to be done on each cable strictly monitor and control the area by standby man or watchman prior that nobody will go on the area. Proper separation of cores and safe distance from adjacent objects.)
E. Discharging (Ensure personnel are wearing appropriate PPE nonconductive gloves must be use and area must be clear and discharge on the apparatus or by bonding into by the grounding bond or rod to drain the stored energy.)
F. Dally housekeeping (Full supervision on the area remind personnel for safe working and good housekeeping on the area should be done before and after the work )
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