International comfort products CSH5 Installation Instructions Manual page 10

INSTALLATION INSTRUCTIONS
Time Delays
The unit time delays include:
S Five minute time delay to start cooling or heating operation
when there is a call from the thermostat. (To bypass this
feature in a non−communicating system, momentarily short
and release forced defrost pins.
S Five minute compressor recycle delay on return from a
brown out condition
S Two minute time delay to return to standby operation from
last valid communications (with Observer communicating
wall control only)
S One minute time delay of outdoor fan at termination of
cooling mode when outdoor ambient is greater than or
equal to 100_F (37.78_C).
S Fifteen second delay at termination of defrost before the
auxiliary heat (W2) is de−energized.
S Twenty second delay at termination of defrost before the
outdoor fan is energized.
S Seventy and sixty second compressor delays when Quiet
Shift−2 enabled.
Utility Interface
With Non−Communicating Thermostats
Utility curtailment will only work when the unit is operating
with a non−communicating thermostat.
When the utility curtailment interface is applied with a
non−communicating thermostat, the utility relay should be
wired between R & Y.
Low Ambient Cooling
When this unit is required to operate below 55_F (12.78_C) to
a minimum of 0 _F (−17.78 _C) outdoor temperature,
provisions must be made for low ambient operation.
Low ambient applications require the installation of
accessory kits:
S Low Ambient Pressure Switch Kit
S Evaporator Freeze Thermostat
S Hard Start kit
S Crankcase Heater
S Field Supplied Isolation Relay
Support feet are recommended for low ambient cooling. See
P ro d u c t S p e c ific a tio n s h e e t f o r k it p a rt n u m b e rs o n
appropriate unit size and series unit.
F o r l o w a m b i e n t c o o l i n g w i t h t h e O b s e r v e r
Communicating Wall Control the cooling lockout must be
set to "Off" in the Wall Control setup.
DEFROST
This control offers 4 possible defrost interval times: 30, 60, 90
or 120 minutes. These are selected by dip switches on the
unit control board, or in the Observer Communicating Wall
Control (if used). The Observer Communicating Wall Control
selection overrides the control board dip switch settings.
Auto defrost is available with Observer Communicating Wall
Control only and it must be enabled in the Wall Control. Auto
defrost adjusts the defrost interval time based on the last
defrost time as follows:
S When defrost time is < 3 minutes, the next defrost interval
= 120 minutes
S When defrost time is 3−5 minutes, the next defrost interval
= 90 minutes
S When defrost time is 5−7 minutes, the next defrost interval
= 60 minutes
10
R−410A Split System Heat Pumps
S When defrost time is > 7 minutes, the next defrost interval
= 30 minutes
The control board accumulates compressor run time. As the
accumulated run time approaches the selected defrost
interval time, the control board monitors the coil temperature
sensor for a defrost demand. If a defrost demand exists, a
defrost cycle will be initiated at the end of the selected time
interval. A defrost demand exists when the coil temperature
is at or below 32_F/0_C for 4 minutes during the interval.
The defrost cycle is terminated when the coil temperature
reaches 65_F/18.33_C or 10 minutes has passed.
If the coil temperature does not reach 32_F/0_C within the
interval, the interval timer will be reset and start over.
NOTE:
S Upon initial power up the first defrost interval is defaulted to
30 minutes. Remaining intervals are at selected times.
S Defrost is only allowed to occur below 50_F/10_C outdoor
ambient temperature.
S The Quiet Shift−2 compressor on/off delays, as described
below, will be included in a forced defrost if Quiet Shift−2 is
enabled.
DEFROST HOLD
In a non−communicating system, if the thermostat becomes
satisfied before the defrost cycle is terminated, the control will
"hold" in defrost mode and finish the defrost cycle on the next
call for heat. Defrost hold is not needed in a communicating
system because the Wall Control will complete the defrost
cycle before shutting down the system.
FORCED DEFROST
F o r c e d d e f r o s t c a n b e i n i t i a t e d m a n u a l l y i n a
non−communicating system, or by communicated command
from a Wall Control. The board contains a 2−pin header
labeled FORCED DEFROST (See Figure 12). To initiate a
forced defrost:
S Manually, short FORCED DEFROST pins for 5 seconds
then release
S If coil temp is at defrost temp of 32_F/0_C, and outdoor air
temperature is below 50_F/10_C, a full defrost sequence
will occur
S If the coil temp or outdoor air temperature do not meet the
above requirements, an abbreviated 30 second defrost will
occur
QUIET SHIFT−2
Quiet Shift−2 is a field−selectable defrost mode which may
eliminate occasional noise that could be heard at the start
and finish of the defrost cycle. For installations using a
standard 2−stage thermostat, this feature must be enabled
by selecting the 3rd position dip switch on the outdoor control
board. For installations using an Observer Wall Control, this
feature must be enabled at the Wall Control. When activated,
the following sequence of operation occurs: Defrost
Initiation − the compressor is de−energized for 70 seconds.
During this 70 second compressor off time, the reversing
valve will be energized. Once the 70 second compressor off
time has been reached, the compressor will be energized
then the outdoor fan will be de−energized at which time the
normal defrost cycle begins. Defrost Termination − the
outdoor fan will be energized shortly before the compressor
is de−energized for 60 seconds. During the compressor 60
second off time, the reversing valve will be de energized.
O n c e t h e 6 0 s e c o n d c o m p re s s o r o ff t im e h a s b e e n
completed, the compressor will be energized at which time
the system will be in normal heat mode.
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