Daikin WGZ030DW Installation, Operation And Maintenance Manual page 64

Primary/Standby Pump Staging
The pump designated as primary will start first. If the
evaporator state is start for a time greater than the recirculate
timeout set point and there is no flow, then the primary
pump will shut off and the standby pump will start. When the
evaporator is in the run state, if flow is lost for more than half
of the flow proof set point value, the primary pump will shut
off and the standby pump will start. Once the standby pump
is started, the flow loss alarm logic will apply if flow cannot be
established in the evaporator start state, or if the flow is lost in
the evaporator run state.
Auto Control
If auto pump control is selected, the primary/standby logic
above is till used. When the evaporator is not in the run state,
the run hours of the pumps will be compared. The pump with
the least hours will be designated as the primary at this time.
Evaporator Water Flow Loss
The Evaporator Water Flow Loss logic allows the Unit to
shutdown compressors on a loss of flow up to two times every
twenty-four hours before locking the unit out on a Evaporator
Flow Loss Alarm.
• If there are no compressors running when Evaporator
Water Flow Loss is indicated the Unit Statuschanges
to Auto:Wait for flow. The evaporator water pump state
changes to Start and no alarms are indicated.
• If an Evaporator Water Flow Loss occurs while a
compressor is running all of the runningcompressors will
be shutdown. The alarm indicators are turned On and
the Circuit Status for anycircuit with running compressors
becomes Off: Ready, the Unit Status becomes Auto: Wait
For Flowand the evaporator water pump state changes to
Start
• When flow is reestablished the Unit Status becomes Auto:
Recirculate while the Evaporator Flow Recirculation Timer
counts down. If there is continuous evaporator water flow
while the EvaporatorRecirculation Timer counts down the
Alarm indicator is turned off, and the unit resumes normal
startup procedures based on water temperature and
cycle timers.
• If second Evaporator Water Flow Loss occurs within
twenty-four hours the process described above is
repeated.
• If a third loss of flow is indicated in a twenty-four hour
time frame the unit will shut down on an Evaporator
Water Flow Loss alarm and it will be locked out until this
alarm is manually cleared.
• The twenty-four hour timer that limits the auto restart is
reset when the control clock rolls over 00:00 each night.
Condenser Fans – Air Cooled
Air-cooled condenser fan control is active only when the water
cooled set point is set to off.
IOM 1322 • WATER-COOLED SCROLL COMPRESSOR
Unit Controller Operation
Fantrol
Fans 1, 3, 5, 7, 9, 11 are for circuit #1, and fans 2, 4, 6, 8, 10,
12 are for circuit 2. Fans 1 and 2 start with the first compressor
on the respective circuit when the ambient temperature is
greater than 75°F. Below75°F, these fans start when the
condenser saturated temperature gets up to the condenser
saturated temperature target. The compressor must be running
in order to run any fans.
Fan Stages
There are 2, 3, 4, 5 or 6 fans available per circuit. On 8, 10,
and 12 fan units, fans 5/7, 6/8, 9/11 and 10/12 are controlled
by one contactor for each pair, using virtual stages to allow a
difference of only one fan between stages, See tables below:
4 and 6-Fan Remote Condenser
Stage Fans Operating on
Circuit 1
1 Fan 1
2 Fans 1 & 3
3 Fans 1,3,5
8-Fan Remote Condenser, R410A
Stage Fans Operating on
Circuit 1
1 Fan 1
2 Fans 1,3
3 Fans 1,5,7
4 Fans 1,3,5,7
10 Fan Remote Condenser, R410A
Stage Fans Operating on
Circuit 1
1 Fan 1
2 Fans 1,3
3 Fans 1,5,7
4 Fans 1,3,5,7
5 Fans 1,3,5,7,9
12 Fan Remote Condenser, R410A
Stage Fans Operating on
Circuit 1
1 Fan 1
2 Fans 1,3
3 Fans 1,5,7
4 Fans 1,3,5,7
5 Fans 1,3,5,7,9
6 Fans 1,3,5,7,9,11
64
Fans Operating on
Circuit 2
Fan 2
Fans 2& 4
Fans 2,4,6
Fans Operating on
Circuit 2
Fan 2
Fan 2,4
Fans 2,6,8
Fans 2,4,6,8
Fans Operating on
Circuit 2
Fan 2
Fans 2,4
Fans 2,6,8
Fans 2,4,6,8
Fans 2,4,6,8,10,12
Fans Operating on
Circuit 2
Fan 2
Fans 2,4
Fans 2,6,8
Fans 2,4,6,8
Fans 2,4,6,8,10
Fans 2,4,6,8,10,12
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