Transformer Evacuation Process
DETAIL TECHNICAL SPECIFICATION
FOR VACUUM PUMPING SYSTEM
SCOPE OF SUPPLY:
The Vacuum Pumping system covered by this specification will be suitable for evacuation of new transformer during installation. The Vacuum Pumping system will be suitable for continuous operation to evacuate surface moisture of new transformer Before installation/charging.
The Vacuum Pumping system will be Stationary Type.
VACUUM PUMPING SYSTEM:
It will mainly consists of the following:
- Rotary Vacuum Pump
- Roots Vacuum Pump
- Trap
- Control Panel, including main isolation switch with fuses of suitable rating for control of inlet power supply.
- Indicating and control instruments including dial type vacuum gauges.
- Inlet Valves, airing valve, etc.
- Vacuum hose 10 mtr. – 1 Nos.
DETAILS OF TRANSFORMER EVACUATION SYSTEM:
INLET HAND OPERATED VALVE:
One No. of hand operated valve will be provided.
AIRING VALVE:
One airing valve will be provided for admitting ait into the vacuum pump before switching off the vacuum pump.
VACUUM PUMPING SYSTEM
Roots – Rotary Combination of vacuum pump will be provided for evacuation of Transformer. The pumps will be of reputed make as given below.
ROTARY OIL SEALED PUMP (1 No.)
Pumping speed : 100 Cum/hr
Make : Busch, Germany/Leybold
MECHANICAL BOOSTER PUMP
Pumping speed : 500 Cum/hr
Make : Busch, Germany/Leybold
The Vacuum Pumping System will be mounted on the base frame.
VACUUM GAUGE:
One Vacuum Gauge bardoun type having diameter of at least 100 mm will be provided to indicate vacuum tank. The vacuum gauge will be fixed so that it will be easily readable from distance.
VACUUM HOSES
It will be provided with One lengths of 10 mtrs. Long each, nitrile / rubber wire braided oil hoses with metallic flanges (of steel) suitable for connection at inlet and outlet. The hose will be capable working vacuum.
PIPES AND FLANGES:
All pipes will be quality and all oil and vacuum connections will be in the form of flanged joints with o rings, ensuring full sealing efficiency at all times with minimum maintenance requirements.
ELECTRIC MOTORS:
Electric motors driving the various pumps will be TEFC squirrel cage induction motors and to operate on 415 volts +/- 10%, 3 phase 50 +/- 5% Hz, AC supply. All motors will generally conform to IS 325 with class F insulation.
PAINTING:
All exposed surfaces will be thoroughly cleaned of all dust, dirt, scale and foreign matter and will be applied with one coat of approved rust preventive compound and finished with two coats of paint.