IOM 1274-3 • CENTRIFUGAL WATER CHILLERS 72 www.DaikinApplied.com
Unit Startup and Maintenance
Service Programs
It is important that an air conditioning system receive adequate
maintenance if the full equipment life and full system benefits
are to be realized.
Maintenance should be an ongoing program from the time the
system is initially started. A full inspection should be made after
3 to 4 weeks of normal operation on a new installation, and on
a regular basis thereafter.
Daikin Applied offers a variety of maintenance services through
the local Daikin Applied service office, its worldwide service
organization, and can tailor these services to suit the needs of
the building owner. Most popular among these services is the
Daikin Applied Comprehensive Maintenance Contract.
For further information concerning the many services available,
contact your local Daikin Applied service office.
Maintenance Schedule Notes
1. Some compressors use power factory correction
capacitors and all have a surge capacitor (excepting
units with solid state starters). The surge capacitor can
be installed out of sight in the compressor motor terminal
box. In all cases, capacitors must be disconnected from
the circuit to obtain a useful Megger reading. Failure to
do so will produce a low reading. In handling electrical
components, only fully qualified technicians must attempt
service
2.
Approach temperature (the difference between the
leaving water temperature and the saturated refrigerant
temperature) of either the condenser or evaporator
is a good indication of tube fouling, particularly in the
condenser, where constant flow usually prevails. Daikin
Applied’s high efficiency heat exchangers have very low
design approach temperatures, in the order of one to one
and one half degrees F.
The chiller unit controller can display the water and the
saturated refrigerant temperatures. Simple subtraction
will give the approach. It is recommended that
benchmark readings (including condenser pressure drop
to confirm future flow rates) be taken during startup and
then periodically afterward. An approach increase of
two-degrees or more would indicate that excessive tube
fouling could be present. Higher than normal discharge
pressure and motor current are also good indicators
3.
Evaporators in closed fluid circuits with treated water
or anti-freeze are not normally subject to fouling, hover
it is prudent to check the approach periodically. Some
evaporators may have a mixture of ¾-inch and 1-inch
tubes.
4. Performed when contracted for, not part of standard
initial warranty service.
5.
Oil filter change and compressor teardown and
inspection should be done based on the results of the
annual oil test performed by a company specializing
in this type of test. Consult Daikin Applied service for
recommendations.
Table 34: Maintenance Schedule
Maintenance Check List Item
Daily
W
eekly
Monthly
Quarterly
Annually
5-Yr
As Req’d
Unit
Operational Log
O
Analyze Operational Log
O
Refrigerant Leak Test Chiller
O
Test Relief Valves or Replace
X
Compressor
Vibration Test Compressor
X
Motor
Meg. Windings (Note 1)
X
Ampere Balance (within 10% at RLA)
O
Terminal Check - measure infrared temp
X
Motor Cooling Filter Drier Pressure Drop
X
Lubrication System
Clean Oil Cooler Strainer (water)
X
Oil Cooler Solenoid Operation
O
Oil Appearance (clear color, quantity)
O
Oil Filter Pressure Drop
O
Oil Analysis (Note 5)
X
Oil change if indicated by oil analysis
X
Controls
Operating Controls
Calibrate Temperature Transducers
X
Calibrate Pressure Transducers
X
Check Vane Control Setting & Operation
X
Verify Motor Load Limit Control
X
Verify Load Balance Operation
X
Check Oil Pump Contactor
X
Protective Controls - Test Operation of:
- Alarm Relay
X
- Pump Interlocks
X
- Guardistor and Surgeguard Operation
X
- High and Low Pressure Cutouts
X
- Oil Pump Pressure Differential Cutout
X
- Oil Pump Time Delay
X
Condenser
Evaluation of Temp Approach (NOTE 2)
O
Test Water Quality
V
Clean Condenser Tubes (NOTE 2)
X
X
Eddy current Test - Tube Wall Thickness
V
Seasonal Protection
X
Evaporator
Evaluation of Temp Approach (NOTE 2)
O
Test Water Quality
V
Clean Evaporator Tubes (NOTE 3)
X
Eddy current Test - Tube Wall thickness
V
X
Seasonal Protection
X
Expansion Valves
Operational Evaluation (Superheat Control)
X
Starter
Examine Contactors (hardware & operation)
X
Verify Overload Setting and Trip
X
Test Electrical Connections (Infrared temp
measurement)
X
Optional Controls
Hot Gas Bypass (verify operation)
X
