Monday, November 14, 2016
Procedure for 33kV Cable AC High Voltage Test !!
3 REFERENCE, CODE & STANDARD
5 RESPONSIBILITY AND AUTHORITY
6 WORK PROCEDURE
9 QUALITY CONTROL
The purpose of this procedure is to specify responsibilities and describe the steps 33kV Cable High Voltage Test.
This method statement describes and performance of associated HI-POT testing of 1C x 400 Sq.mm 33KV cable. This method statement is intended to cover the basic test set layout specific to the site and safety conditions required to carry out the test without posing a danger to personnel and equipment.
This method statement is not intended to cover the physical connection of the test equipment nor the actual test procedure.
3 CODE & STANDARD
3.1 Subcontractor document
3.2 Work index, symbol and detailed drawing
3.3 Address the related project specific CODE & STANDARD.
4.1 Within this document following definitions shall apply.
OWNER / COMPANY United Steel Company (Kingdom of Bahrain)
CONTRACTOR Samsung Engineering Company Limited (SECL)
PROJECT SULB Steel Mill Project (Kingdom of Bahrain)
5 RESPONSIBILITY AND AUTHORITY
5.1 Site Manager
5.1.1 Site manager bears the responsibility and authority on work and quality related to this method statement.
51.2 Site manager approves work plans.
5.2 Construction Superintendent
5.2.1 A construction Superintendent bears the responsibility and authority to train their staff and subcontractor’s after preparing work plan according to this method statement.
5.2.2 A construction team manager takes the responsibility of all temporary electrical work execution and preparation.
5.3 Construction Supervisor
5.3.1 Construction Supervisor shall execute inspections and tests to secure quality materials, take adequate measures, manage results as quality records, and utilize checklist.
5.3.2 Construction supervisor bears the responsibility of installing cable tray according to the dimensions specified in specifications or drawings, and submits reports to the owner for approval
5.4 Quality Manager
5.4.1 Site Quality Manager is responsible for management and supervision of implementing inspection work as specified in this method statement.
5.4.2 Inspection request to QC when portions of the work are ready for inspection, as depicted in the ITP’s.
5.4.3 Responsible for preservation and maintenance of equipment at site.
6 WORKING PROCEDURE
6.1 Sheath Test
6.1.1 Performing DC sheath test by applying 10kV to Metallic sheath against Ground for 5 Minute.
6.2 Link Box Installation and Testing.
6.1.1 Link Box installation near of 33KV connection point.
6.1.2 Link Box bonding cable size 1Cx95mm2.
6.1.3 Link Box shall be two ground cables provide 1Cx120mm2.
6.1.4 Link Box Installation height shall be 1500mm from floor to link box center point.
6.1.5 Bonding cable Insulation resistance test by DC 5kV Voltage.
6.1.6 SVL Insulation resistance test by DC 1kV Voltage.
6.1.7 Link box contact resistance test at each phase and earthling connection.
6.3 AC High Voltage Test & Insulation Resistance Test
6.3.1 The test set will be connected from 33kV GIS panel side through a suitable test busing. At the far end of the circuit the cables are terminated at SULB substation, during execution all necessary safety procedures to be followed for a smooth working environment.
6.3.2 In live condition. Only the test engineer will be allowed into the test area marked out by the warning tapes, this will be stressed to the watchmen and no personnel on the site will be allowed inside the test area regardless of their status.
6.3.3 Once the test set and test object have been connected the test engineer will recheck the safety barriers and ensure watchmen are positioned. The test set ground will be removed and the cable and test system should now be considered live. The test set wills then energies the test object as per the Clients requirements. In the event of no specific client requirements SECL advice to raise the test voltage to 33kV and hold for enough time to allow the test engineer to inspect the test lead and test object, then raised to the full test voltage. This method allows the test engineer to ensure the set is correctly connected and the clearance from live components and earth is sufficient to avoid a flash over.
6.3.4 Performing Insulation resistance test to be done before and after high voltage test, it’s done between conductor and ground applied DC 5kV 1 minute.
6.3.5 AC voltage 33KV Applied for 5 minute to conductor with corresponding sheath earth, and recording the leakage current after full voltage applied. No break down or excessive leakage current. Before performing theses tests following condition have to be applied.
7 QUALITY CONTROL
7.1 ITP is a document submitted to the owner or owner’s representative formulated in an orderly manner by the construction supervisor or site quality manager to record main working processes for tests and quality inspections, and to enable the owner or owner’s representative to assign inspection points.
7.2 Witness Point
7.2.1 Point where permission to the next level is granted without Owner’s agreement.
7.3 Hold Point
7.3.1 Point where further progress is not allowed without Owner’s written permission
7.4.1 Person that inspects whether processes quality of materials or specifications are consistent with prescribed or desired requisites.