Carrier 50HCQ04---12 User Manual
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Dehumidification Test
For units with the factory Reheat option, the
dehumidification relay is used to change the output status
to operate the circuits in different Reheat modes.
Dehumidification relay on by itself puts all circuits
running in Hot Gas Reheat dehumidification mode;
dehumidification relay on and the cooling test
(compressor test relays) on puts unit and or individual
circuits in subcooling dehumidification mode. The fans
and heating service test outputs are reset to “Disable” for
the dehumidification service test. Indoor and outdoor fans
are controlled normally to maintain proper unit operation.
All normal cooling/dehum alarms and alerts are
functional.
Power Exhaust Test
This point allows the board’s power exhaust (PE) output
to be manually turned On (Enable) and Off (Disable).
Power Exhaust test can operate simultaneously with other
Service Test Points.
Economizer Test
This point allows the board’s economizer output to be
manually controlled from 0 to 100 % Open. Economizer
test can operate simultaneously with other Service Test
Points.
Analog Output 2 Test
This test point activates the AO2 0-10vdc analog output at
J22. These rooftops do not use this output, therefore this
test is not used.
NOTE: Service Test Mode does not timeout. Be sure to
turn off test mode or cycle power to the RTU to return to
normal operation.
Configuration
The RTU-OPEN controller’s configuration points effect
the unit’s inputs and operation. Review and understand
the meaning and purpose of each configuration point
before changing it from the factory default value. Use the
RTU-OPEN Start-up Sheet during configuration; fill in
changed values if changed from factory default. There are
three main configurations menus: SETPOINT, UNIT, and
SERVICE. Each configuration point is described below
under its according menu. See Appendix A for BACview
menu structure.
Setpoint
Occupied Heating Setpoint -- The heating setpoint the
controller maintains during the occupied period.
Range = 40-90_F
Occupied Cooling Setpoint – The cooling setpoint the
controller maintains during the occupied period.
Range = 55-99_F
Unoccupied Heating Setpoint – The heating setpoint the
controller maintains during the unoccupied period.
Range = 40-90_F
Unoccupied Cooling Setpoint – The cooling setpoint the
controller maintains during the unoccupied period.
Range = 55-99_F
Effective Heating Setpoint – The current setpoint value
heating operation will control to.
Effective Cooling Setpoint – The current setpoint value
cooling operation will control to.
Optimal Start - The earliest time prior to occupancy, at
which the Optimal Start function may begin to adjust the
effective setpoints. Setting this to 0 will disable optimal
start.
Range = 0-4 hours
Default = 4 hours
Occ Relative Humidity Setpoint – The space RH
setpoint the controller maintains during the occupied
period.
Range = 0 to the Unocc RH setpoint
Default 60%
Unocc Relative Humidity Setpoint – The space RH
setpoint the controller will maintain during the
unoccupied period.
Range = 30-100%
Default = 90%
DCV Max Ctrl Setpoint – The difference between indoor
and outdoor CO
2
level which results in maximum
ventilation damper position.
Range = 0-9999ppm Default = 650ppm
Power Exhaust Setpoint – When the economizer damper
position opens above this point the power exhaust
operation will begin. When the damper position falls
below this point and 5% lower the power exhaust will
shutdown.
Range = 20-90%
Default = 50%
NOTE:
This point is only used when Continuous
Occupied Exhaust = NO
Unit
Fan Mode – Sets the operation of the indoor fan when not
in cooling or heating mode. Refer to fan operation for
details on each operation.
Range = Auto, Continuous, or Always On
Default = Continuous
Unit Start Delay – Refers to the time delay the unit will
wait after power up or when transitioning from
unoccupied to occupied before it pursues any specific
operation.
Range = 0-30 sec
Default = 5 sec
Fan Off Delay – Time delay in which the fan will
continue run after being commanded off.
Range = 0-180sec
Default = 90sec
Minimum Cooling SAT – The supply air temperature
must remain above this value to allow cooling with the
economizer and/or compressors. There is 5_F plus and
minus deadband to this point. If the SAT falls below this
value during cooling a compressor stage will be removed
and/or the economizer will return to minimum position.
Range = 45-70_F
Default = 50_F
Maximum Heating SAT – The supply air temperature
must remain below this value to allow heating. There is
5_F plus and minus deadband to this point. If the SAT
falls below this value during heating the heat stages will
begin to decrease until the SAT has dropped below this
value.
Range = 95-150_F
Default = 120_F