Comfort-Aire HBH Series 6-10 Tons - Manual (Page 26)

IOM Manual HBH SERIES Heat Controller, Inc.
25
Safety Features
Safety Features – CXM Control
The safety features below are provided to protect the
compressor, heat exchangers, wiring and other components
from damage caused by operation outside of design
conditions.
Anti-short cycle protection: The control features a 5
minute anti-short cycle protection for the compressor.
Note: The 5 minute anti-short cycle also occurs at
power up.
Random start: The control features a random start upon
power up of 5-80 seconds.
Fault Retry: In Fault Retry mode, the Status LED begins
slowly flashing to signal that the control is trying to recover
from a fault input. The control will stage off the outputs and
then “try again” to satisfy the thermostat input call. Once the
thermostat input call is satisfied, the control will continue on
as if no fault occurred. If 3 consecutive faults occur without
satisfying the thermostat input call, the control will go into
“lockout” mode. The last fault causing the lockout will be
stored in memory and can be viewed by going into test mode
(CXM board). Note: FP1/FP2 faults are factory set at only
one try.
Lockout: In lockout mode, the status LED will begin fast
flashing. The compressor relay is turned off immediately.
Lockout mode can be “soft” reset by turning off the
thermostat (or satisfying the call). A “soft” reset keeps
the fault in memory but resets the control. A “hard” reset
(disconnecting power to the control) resets the control and
erases fault memory.
Lockout with emergency heat: While in lockout mode, if W
becomes active (CXM), emergency heat mode will occur.
High pressure switch: When the high pressure switch
opens due to high refrigerant pressures, the compressor
relay is de-energized immediately since the high pressure
switch is in series with the compressor contactor coil. The
high pressure fault recognition is immediate (does not
delay for 30 continuous seconds before de-energizing the
compressor).
High pressure lockout code = 2
Example: 2 quick flashes, 10 sec pause, 2 quick flashes, 10
sec. pause, etc.
Low pressure switch: The low pressure switch must be open
and remain open for 30 continuous seconds during “on”
cycle to be recognized as a low pressure fault. If the low
pressure switch is open for 30 seconds prior to compressor
power up it will be considered a low pressure (loss of
charge) fault. The low pressure switch input is bypassed for
the initial 120 seconds of a compressor
run cycle.
Low pressure lockout code = 3
Water coil low temperature (FP1): The FP1 thermistor
temperature must be below the selected low temperature
limit setting for 30 continuous seconds during a compressor
run cycle to be recognized as a FP1 fault. The FP1 input is
bypassed for the initial 120 seconds of a compressor run
cycle. FP1 is set at the factory for one try. Therefore, the
control will go into lockout mode once the FP1 fault has
occurred.
FP1 lockout code = 4
Air coil low temperature (FP2): The FP2 thermistor
temperature must be below the selected low temperature
limit setting for 30 continuous seconds during a compressor
run cycle to be recognized as a FP2 fault. The FP2 input
is bypassed for the initial 60 seconds of a compressor run
cycle. FP2 is set at the factory for one try. Therefore, the
control will go into lockout mode once the FP2 fault has
occurred.
FP2 lockout code = 5
Condensate overflow: The condensate overflow sensor
must sense overflow level for 30 continuous seconds to
be recognized as a CO fault. Condensate overflow will be
monitored at all times.
CO lockout code = 6
Over/under voltage shutdown: An over/under voltage
condition exists when the control voltage is outside the range
of 19VAC to 30VAC. Over/under voltage shut down is a
self-resetting safety. If the voltage comes back within range
for at least 0.5 seconds, normal operation is restored. This is
not considered a fault or lockout. If the CXM is in over/under
voltage shutdown for 15 minutes, the alarm relay will close.
Over/under voltage shut down code = 7