Daikin Trailblazer AGZ030-101E Installation, Operation And Maintenance Manual page 77

evaporator recirculation time will be limited to 110 seconds
or less. The evaporator recirculation time set point will not be
changed. Only the value used in the evaporator state logic will
be limited, and only if the set point exceeds the 110 second
limit. This action will ensure that the chiller is ready to start
after the motor protection module delay has expired.
RapidRestore will end if the unit reaches full capacity, all
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circuits or unit become disabled for any reason, 10 minutes
have passed since unit powered up, or LWT is less than Stage
Up Temperature.
Motor Protection Start Delay
The compressor manufacturer requires a minimum two minute
delay after power on until a compressor should be started,
which is to ensure proper operation of the motor protection
modules. Unit controller boot time is about 10 seconds, so a
delay of 110 seconds will start upon completing boot up. After
this delay, the two minute manufacturer requirement will be
satisfied.
After the 110 second delay, the first circuit to start will enter the
preopen state, which takes five seconds. The end result is that
the first compressor should start approximately 125 seconds
after power is restored to the chiller.
A longer delay for motor protection modules will still be used
for normal starts.
Fast Loading
Fast loading will be performed while RapidRestore
Capacity Changes
Normally the delay between compressors staging on is
determined by the Stage Up Delay setting. That setting
defaults to 240 seconds and has a range of 120 to 480
seconds. During fast loading, a delay of 60 seconds between
compressor starts within a circuit should be used. In addition,
a delay of 30 seconds between compressor starts on different
circuits should be used.
This change during RapidRestore
faster time to full capacity while maintaining stable operation
within each circuit. Assuming both circuits are able to run, the
effective unit stage up delay will be 30 to 35 seconds, so it will
load about four times faster during RapidRestore
fastest it possibly can during normal operation.
Max Pulldown Rate
Max pulldown rate will be ignored during fast loading so the
chiller can reach full capacity as soon as possible.
Backup Chiller Operation
If the Backup Chiller input (DI2) on the RapidRestore
has a signal and the unit has RapidRestore
the chiller is considered a 'backup chiller'. When a 'backup
chiller' is enabled, it will use an evaporator recirculation time
of 13 seconds regardless of what the evaporator recirculation
time set point is. Then, fast loading will be used as outlined
previously.
www.DaikinApplied.com
® is active.
operation will allow for a
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than the
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module
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enabled, then
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This backup chiller sequence is safe for the unit if it has had
power applied for the minimum time stated in the operation
manual. Since this sequence does not have to wait on the
compressor motor protection module delay, the unit can
achieve full capacity even faster than during a power loss
scenario.
Compressor Starts Per Hour
Since the compressor cycle timers are not maintained through
power cycling, a limitation on the number of starts per hour
will be added. Each compressor will be allowed six starts in an
hour.
If a compressor start is being delayed due to this limitation,
it can be cleared by using the existing Clear Cycle Timers
setting.
The following table shows the approximate best case scenario
for start time and loading time with the RapidRestore
operation.
Table 60: RapidRestore
# of compressors
4
Power lost
and restored
6
Backup
4
chiller with
constant
6
power
Sound Reduction
A special mode of operation is available for E vintage models
with two fan VFD's per circuit, which reduces sound levels by
limiting condenser fan speeds. This mode can be enabled and
disabled via the Sound Reduction Enable setting.
Scheduling
When enabled, sound reduction will become active based on
a daily schedule. This schedule is configurable and allows a
start time and duration to be selected for each day of the week.
Start times can be set in one hour increments and duration can
be set in hour increments.
Sound reduction will be active if the controller time is within the
time block determined by the settings for the current day.
Operation When Active
When sound reduction is active, the condenser fans will be
limited to the speed selected by the fan speed limit set point.
If the Sound Reduction priority is set to 'sound', the fan speed
limit is applied at all times regardless of operating conditions. If
conditions are such that condenser pressure is elevated a high
pressure stage down may occur, which would effectively lower
77 IOM 1206-13 • TRAILBLAZER
Unit Functions
® Mode Response Times
Maximum Time to
Restart Time Fully Loaded
220 sec.
125 sec.
280 sec.
115 sec.
20 sec.
175 sec.
MODEL AGZ CHILLERS
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