Daikin Trailblazer AGZ030E-070E, Инструкция по установке, эксплуатации и обслуживанию

Страница: 92 / 148

IOM 1207-6 • TRAILBLAZER
®
MODEL AGZ CHILLERS 92 www.DaikinApplied.com
Unit Functions
changed to use the 110 second delay discussed above only
when the chiller is performing the RapidRestore operation.
Fast Loading
Fast loading will be performed when the following conditions
are met after the unit power up:
• Chiller enters RapidRestore
®
operation
• Current LWT > Start Up Temperature
For reference, Start Up Temperature is Stage Up Temperature
+ Start Up Delta T. Stage Up Temperature is calculated based
on the Full Capacity Evaporator Delta T set point and the
number of compressors on the chiller.
Fast loading should end if any of the following conditions occur:
• LWT < Stage Up Temperature
• Unit capacity = 100%
• All circuits become disabled for any reason
• Unit becomes disabled for any reason
• 10 minutes have passed since unit powered up
When fast loading ends, the RapidRestore
®
operation is
considered complete.
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
®
operation will allow for a
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
®
than the
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 DI2 on the RapidRestore
®
module has a signal and the unit
has RapidRestore
®
enabled, then 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 in the fast loading
section.
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 Starting
During normal operation, chiller controls will limit compressor
starts by enforcing the circuit configuration timers listed in
Table 44 on page 75 These timers are further discussed on
page 95 . During RapidRestore operation, the compressor
cycle timers are not maintained through power cycling. The
following table shows the approximate best case scenario for
start time and loading time with the RapidRestore
®
operation.
Table 56: RapidRestore
®
Mode Response Times
# of compressors
Maximum
Restart Time
Time to
Fully Loaded
Power lost
and restored
4
125 sec.
220 sec.
6 280 sec.
Backup chiller
with constant
power
4
20 sec.
115 sec.
6 175 sec.
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
the pressure into a safe zone but capacity of the chiller would
be limited.
When priority is set to ‘capacity’, the fan speed limit is in effect
unless saturated condenser temperature rises to a certain
value. That value is the high condenser pressure unload set
point converted to saturated temperature, less 5.56°C (10°F).
Once the condenser saturated temperature starts to exceed
that value, the fans will speed up beyond the speed limit as
needed to control the saturated temperature to that value.This
action allows the chiller to maintain a higher operating capacity.