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3.
Open the compressor disconnect switch, and remove the fuses
. If the transformer is used for control
voltage, the disconnect must remain on to provide power to the oil heater.
Set the manual UNIT
ON/OFF switch in the Unit Control Panel to the OFF position.
4.
Check for corrosion and clean and paint rusted surfaces.
5.
Clean and flush water tower for all units operating on a water tower. Make sure tower blowdown or bleed-
off is operating. Set up and use a good maintenance program to prevent “liming up” of both tower and
condenser. It should be recognized that atmospheric air contains many contaminants that increase the need
for proper water treatment. The use of untreated water can result in corrosion, erosion, sliming, scaling or
algae formation. It is recommended that the service of a reliable water treatment company be used. Daikin
assumes no responsibility for the results of untreated or improperly treated water.
6.
Remove condenser heads at least once a year to inspect the condenser tubes and clean if required.
Annual Startup
A dangerous condition can exist if power is applied to a faulty compressor motor starter that has been burned out.
This condition can exist without the knowledge of the person starting the equipment.
This is a good time to check all the motor winding resistance to ground. Semi-annual checking and recording of this
resistance will provide a record of any deterioration of the winding insulation. All new units have well over 100
megohms resistance between any motor terminal and ground.
Whenever great discrepancies in readings occur, or uniform readings of less than 50 megohms are obtained, the
motor cover must be removed for inspection of the winding prior to starting the unit. Uniform readings of less than
5 megohms indicate motor failure is imminent and the motor should be replaced or repaired. Repair before failure
occurs can save a great deal of time and labor spent in the cleanup of a system after a motor burnout.
1.
The control circuit must be energized at all times, except during service. If the control circuit has been off
and oil is cool, energize oil heaters and allow 24 hours for heater to remove refrigerant from the oil before
starting.
2.
Check and tighten all electrical connections.
3.
Replace the drain plug in the cooling tower pump if it was removed at shutdown time the previous season.
4.
Install fuses in main disconnect switch (if removed).
5.
Reconnect water lines and turn on supply water. Flush condenser and check for leaks.
6.
Refer to Manual OM CentrifMicro II before energizing the compressor circuit.
Repair of System
Pressure Relief Valve Replacement
Current condenser designs use two relief valves separated by a three-way shutoff valve (one set). This three-way
valve allows either relief valve to be shut off, but at no time can both be shut off. In the event one of the relief valves
are leaking in the two valve set, these procedures must be followed:
•
If the valve closest to the valve stem is leaking, back seat the three-way valve all the way, closing the port to
the leaking pressure relief valve. Remove and replace the faulty relief valve. The three-way shutoff valve
must remain either fully back seated or fully forward to normal operation. If the relief valve farthest from
the valve stem is leaking, front seat the three-way valve and replace the relief valve as stated above.
•
The refrigerant must be pumped down into the condenser before the evaporator relief valve can be removed.
Pumping Down
If it becomes necessary to pump the system down, extreme care must be used to avoid damage to the evaporator
from freezing. Always make sure that full water flow is maintained through the chiller and condenser while pumping
down. To pump the system down, close all liquid line valves. With all liquid line valves closed and water flowing,
start the compressor. Set the MicroTech II control to the manual load. The vanes must be open while pumping down
to avoid a surge or other damaging condition. Pump the unit down until the MicroTech II controller cuts out at
