Pre –Start Cheeks:-
- Check water level in cooling tower, should maintain 12” level in the cooling tower basin. Adjust the float valve to maintain the level.
- Check water level in chilled water tank, it should be at least at the half level in the tank.
- Check Oil level in all the compressor as well as the individual Compressor intended to be stated. Should not be less than the low level mark on the oil level sight glass.
- Check the section valves of the compressor as well as the one provided on each of the PHE chiller are fully open
- Check the discharge valves of all the compressor are open except the one under maintenance.
- Open both the liquid line valves (Both Inlet & Outlet) at Receiver
- Open the liquid line valve before the filter/Drier for individual PHE chiller.
- Open chilled water line valves (Both Supply and Return)
- Open cooling tower water line valves (Both Supply and Return)
- Check the voltage in all the three phases i.e., RYB minimum voltage for starting 400 V
- Check all the MCB’s are ON except those Compressor’s MCB which are not to be started or not in operation or under Maintenance
Starting of Compressors:-
In Manual Mode-
The sequence of starting shall be:-
- Start Condenser / cooling tower pump and observe the pressure change in the gauge fitted on top of the pump.
- Switch ON the chiller pump observe the pressure change in the gauge fitted on outlet of the chiller pump.
- Switch ON the cooling tower fan.
- Switch ON the Compressor and check the following:-
- Starting Current/ Normal Running Current.
- Suction Pressure, the suc. Pressure may fall up to 40 PSI in starting but soon it should settle down at around 50PSI, in any case if it falls below 45 PSI in reported immediately.
- Oil Pressure, the differential between Oil Pressure and the suction Pressure should be at least 25PSI, the Oil Pr. Safety should trip below 21PSI. In case the Oil Pr. Safety Trips, the reason must be investigated. Check Oil level in Cop. If safety trips.
In Auto – mode:-
- Follow all the pre- start checks as Mentioned above in the same sequence.
- Put OFF the MCB of the compressor not intended to be started.
- Move the Rotary Switch, Auto Position. This will Energize the starting sequence, steps.
- to (iv) as mentioned in manual starting mode above simultaneously i.e Starting of condenser Pump, cooling tower fan, chiller pump and the selected Compressor etc. at once. Check the following immediately:-
- start in current/ Normal Running Current.
- Suction Pressure, the Pressure any fall up to 40 PSI in staring but soon it should settle down at around 50 PSI in any case if it falls below 45 PSI in continues Running the reason must be investigated and reported immediately.
- Oil Pressure, the differential between Oil Pressure and the suction Pressure should be at least 25 PSI the Oil Pr. Safety should trip, below 21 PSI. In case the Oil Pr. Safety trips, the reason must investigated. Check Oil level in comp. if safety trips.
- Observe any abnormal sound in compressor or Pumps, in case there is any abnormality observed stop the Plant & investigate the reason before restarting.
- Check the Pressure in the Guages Provided on the Chiller and Condenser Pumps.
- Record all the parameters viz., LP/HP, OP, Current, Chiller & Condenser Water Pressure when stabilized.
- Record all Parameters in LOG Book before stopping the Plant.
- Switch Off the Compressor, in case of running in Manual mode and then Switch off the Condenser and Chiller Pumps at least 5 minutes after the Compressor.
- Switch off the main supply to the Control Panel of the plant after 30minutes, in case the plant is not required to run for the next 4 – 5 hour.
- In case of Auto – Mode after recording all the parameters Switch off the plant by turning the Auto Switch to manual position and run the chiller and con denser pumps at least for 5 minutes and then follow the step iii above.