POWER FACTOR CORRECTION BOARDS
The power factor correction boards (hereinafter referred to as “board”) shall be suitable for operation on a 240/415 V, 3 phase, 4 wire, 50 Hz. system with solidly earthed neutral. Unless otherwise specified, the board shall be capable of withstanding the fault condition of not less than 50 kA at 415 V for 1 s as defined in IEC 60439-1.
The board shall not form part of but shall be independent and match the height and depth of the switchboard it is connected to. The board shall be self-contained, floor mounted, flush fronted, metalclad cubicle suitable for front and rear access, fabricated from rolled steel sections of thickness not less than 2.5 mm for framework and 2.0 mm for all panels, covers, and doors. They shall be of Form 2b separation with busbars separated from the switchgears and the incoming and outgoing terminals by metallic or non-metallic rigid barriers or partitions.
The board shall provide adequate dimensions for efficient natural heat dissipation of the capacitors and reactors at normal ambient temperature. The capacitors shall be separated at not less than 80 mm apart. All ventilation vent shall be provided with filter. In addition, ventilation fan with automatic shutter of capacity not less than 200 cubic metre per hour shall be installed. The fan complete with control switch and indicating lamp shall operate either automatically and/or manually with thermostat control at preset temperature.
The board shall undergo de-rusting treatment, anti-rust treatment and be finished with epoxy dry-powder and oven baked semi-gloss enamel grey.
Busbars shall conform to BS 159 and shall be tinned hard drawn high conductivity copper with an adequate uniform rectangular cross section to carry continuously their rated current without overheating. They shall be rigidly mounted on non-hygroscopic insulators so as to withstand any mechanical stresses to which they may be subjected under maximum fault condition.
Busbar sizes must not be less than that specified in the Drawings. However if the busbar sizes are not specified, then the busbar rating shall be based on a current density of not more than 1.5 A/sq. mm. In any case, the busbars rating shall not be less than the rating of the incoming switchgear.
Where multiple parallel bars are used, they shall be separated by tinned copper spacers at spacing equal to the busbar thickness. The main busbars shall be run for the full length of the board without reduction in size. Neutral busbar shall be of full size and full length as the phase busbars.
Connections shall be made up with bronze or other copper alloy bolts and nuts utilising tension washers on both outer faces. Tinned copper earthing bar of cross sectional area not less than 50 mm x 6 mm shall run along the board for its entire length.
6.3 SHOP DRAWINGS
Two copies of shop drawings for the board showing the dimensional general arrangement and layout of the equipment and the schematic line diagram shall be submitted to the S.O.’s Representative for approval. No fabrication of the board shall proceed without the shop drawings being approved by the S.O.’s Representative.
After the installation work has been completed and before Certificate of Practical Completion is issued, the whole electrical installation covered under this part of the Contract shall be tested as prescribed in Electricity Regulations 1994 and IEC 60364 and any other tests deem necessary by the S.O.’s Representative. In the event the installation fails to pass any of these tests, the Electrical Contractor shall take such measures as are necessary to remedy the defects and the
installation shall not be considered as completed until all such tests have been passed.
The tests to be carried out by the Electrical Contractor shall consist of the following tests as a minimum requirement:-
(a) Continuity of protective conductors including main and supplementary equipotential bonding;
(b) Insulation resistance;
(d) Functional testing – operational tests for regulators and circuit breakers, on-off test for switches, etc.
All protection relays and device and power factor regulators shall be checked, tested and calibrated by an Electrical Services Engineer registered with Jabatan Bekalan Elektrik Malaysia. Stability and functionality test shall also be carried out to ensure the installation is in safe and good working order. The Electrical Contractor shall arrange with the Electrical Services Engineer to conduct and carry out the necessary check, test and calibration of the protection relays and
device and regulators. Fee required for the check, test and calibration as described above is deemed to be included in the Contract.