Daikin Navigator WWV Installation, Operation And Maintenance Manual page 49

refrigerant flow. Refrigerant gas flashing in the sight glass
could also indicate an excessive pressure drop in the liquid
line, possibly due to a clogged filter-drier or a restriction
elsewhere in the liquid line. At full load operating conditions,
subcooling values will be approximately 7.2°F (4°C) and
suction superheat values will be approximately 0.9°F (0.5°C).
An element inside the sight glass indicates the moisture
condition corresponding to a given element color. If the sight
glass does not indicate a dry condition after about 12 hours of
operation, an oil acid test is recommended.
Do not use the sight glass on the EXV body for refrigerant
charging. Its purpose is to view the position of the valve.
Pump Operation
It is highly recommended that the chiller unit control the chilled
water pump(s). The integral chiller control system has the
capability to selectively start pump A or B or automatically
alternate pump selection at each start and also has pump
standby operation capability.
Failure to have the chiller control the pumps may cause the
Compressor VFD
Table 31: Compressor VFD Inspection Areas
Inspection Area Inspection Points
Inspect equipment for discoloration from
overheating or deterioration.
General
Inspect for dirt, foreign particles, or dust collection
on components
Conductors and Inspect wiring and connections for discoloration,
Wiring damage or heat stress.
Inspect terminals for loose, stripped, or damaged
Terminals
connections.
Inspect contactors and relays for excessive noise
during operation.
Relays and
Contactors
Inspect coils for signs of overheating such as
melted or cracked insulation.
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following problems:
1. If any device, other than the chiller, should try to start
the chiller without first starting the pumps, the chiller will
lock out on the no-flow alarm and require a manual reset
to restart. This can be disruptive to the normal cooling
process.
2. In areas where freeze-up is a concern, the chiller control
senses the chilled water temperature. It also signals the
chilled water pump to start to providing flow through the
evaporator and additional protection against evaporator
and outside pipe freeze-up . Other pump starting
methods will not automatically provide this protection.
Note: the owner/operator must be aware that when the
water temperature falls below freezing temperatures it
is imperative NOT to stop the pump(s) as immediate
freeze-up can occur.
This method of freeze protection is only effective as
long as the facility and the chiller have power. The only
positive freeze protection during power failures is to
drain the evaporator and blow out each tube or add the
appropriate concentration of glycol to the system.
Corrective Action
Replace damaged equipment as required.
Inspect door seal if so equipped. Use dry air to clear
foreign matter.
Repair or replace damaged wire.
Tighten loose screws and replace damaged screws or
terminals.
Check coil voltage for over or under voltage condition.
Replace damaged removable relays, contactors or circuit
board.
49 IOM 1264-1 • NAVIGATOR
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ysTem aInTenanCe
MODEL WWV CHILLERS
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