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Electrical System
Maintenance of the electrical system involves the general requirement of keeping contacts clean and connections
tight and checking on specific items as follows:
The compressor current draw should be checked and compared to nameplate RLA value. Normally, the
1.
actual current will be lower, since the nameplate rating represents full load operation. Also check all pump
and fan motor amperages, and compare with nameplate ratings.
Inspection must verify that the oil heaters are operative. The heaters are insert-cartridge type and can be
2.
checked by ammeter reading. They should be energized whenever power is available to the control circuit,
when the oil temperature sensor calls for heat, and when the compressor is inoperative. When the
compressor runs, the heaters are de-energized. The Digital Output screen and second View screen on the
operator interface panel both indicate when the heaters are energized.
At least once a quarter, all equipment protection controls except compressor overloads should be made to
3.
operate and their operating points checked. A control can shift its operating point as it ages, and this must be
detected so the controls can be adjusted or replaced. Pump interlocks and flow switches should be checked
to be sure they interrupt the control circuit when tripped.
The contactors in the motor starter should be inspected and cleaned quarterly. Tighten all terminal
4.
connections.
The compressor motor resistance to ground should be checked and logged semi-annually. This log will track
5.
insulation deterioration. A reading of 50 megohms or less indicates a possible insulation defect or moisture
and must be further checked.
The centrifugal compressor must rotate in the direction indicated by the arrow on the rear motor cover plate,
6.
near the rotation sight glass. If the operator has any reason to suspect that the power system connections
have been altered, (phases reversed) the compressor must be jogged to check rotation. For assistance, call
the local Daikin service location.
Cleaning and Preserving
A common cause of service calls and equipment malfunction is dirt. This can be prevented with normal maintenance.
The system components most subject to dirt are:
1. Permanent or cleanable filters in the air handling equipment must be cleaned in accordance with the
manufacturer's instructions; throwaway filters should be replaced. The frequency of this service will vary
with each installation.
2. Remove and clean strainers in chilled water system, oil cooler line and condenser water system at every
inspection.
Seasonal Servicing
Prior to shutdown periods and before starting up again, the following service procedures must be completed.
Annual Shutdown
Where the chiller can be subject to freezing temperatures, the condenser and chiller must be drained of all water.
Dry air blown through the condenser will aid in forcing all water out. Removal of condenser heads is also
recommended. The condenser and evaporator are not self-draining and tubes must be blown out. Water permitted
to remain in the piping and vessels can rupture these parts if subjected to freezing temperature.
Forced circulation of antifreeze through the water circuits is one method of avoiding freeze up.
1. Take measures to prevent the shutoff valve in the water supply line from being accidentally turned on.
2. If a cooling tower is used, and if the water pump will be exposed to freezing temperatures, be sure to remove
the pump drain plug and leave it out so any water that can accumulate will drain away.
D–EIMWC00808-16HU - 51/64
Never Megger a motor while in a vacuum. Severe motor damage can result.
CAUTION
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