Carrier 48PG03-16 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 85

PROBLEM
Subcooling Reheat Mode S bcooli g Reheat Mode
Will Not Activate. Will Not Activate
Hot Gas Reheat Mode Hot Gas Reheat Mode
Will Not Activate. Will Not Activate.
No Dehumidification
Demand.
CRC Relay Operation. CRC R l y O p i
CV or RH1 Valve Operation CV or RH1 Valve Operation.
(NOTE: Normally Open (NOTE: Normally Open
When De-energized) When De-energized)
RH2 Valve Operation. RH2 Valve Operation
(NOTE: Normally Closed (NOTE: Normally Closed
When De-energized) When De-energized)
Low Latent Capacity
in Subcooling or Hot Gas
Reheat Modes.
Low Sensible Capacity
in Normal Cool or
Subcooling Reheat Modes.
Low Suction Pressure
and High Superheat and High Superheat
During Normal Cool Mode.
Low Suction Pressure Low Suction Pressure
and High Discharge Pressure.
RH2 Valve Cycling On/Off.
Circuit B or C Will
Not Operate With
Circuit A Off.
LEGEND
CRC --- --- Cooling/Reheat Control
CV --- --- Cooling Valve
RH --- --- Relative Humidity
Table 94—Humidi-MiZer™ Service Analysis
CAUSE
General cooling mode problem.
No dehumidification demand.
CRC relay operation.
Circuit RH1 valve is not open.
Circuit CV valve is not closed.
General cooling mode problem.
No dehumidification demand.
CRC relay operation.
Circuit RH1 valve is not open.
Circuit CV valve is not closed.
Circuit RH2 valve is not open.
Outdoor temperature too low.
Relative humidity setpoint is
too low — Humidistat
Relative humidity setpoint is
too low — RH sensor.
Software configuration error
for accessory humidistat.
Software configuration error
for accessory humidity sensor.
No humidity signal.
No 24V signal to input terminals. N 24V i g l i p i l
No power to output terminals.
Relay outputs do not change state.
No 24V signal to input terminals. N 24V i g l i p i l
Solenoid coil burnout Solenoid coil burnout.
Stuck valve.
N 24V i No 24V signal to input terminals. g l i p i l
Solenoid coil burnout. Solenoid coil burnout
Stuck valve.
CV valve open or leaking.
RH2 valve open or leaking.
General cooling mode problem.
RH2 valve open or leaking.
General cooling mode problem.
Both RH1 and CV valves closed.
Hot Gas Reheat mode low
suction pressure limit.
Normal operation. Motormaster
outdoor fan control requires
operation of circuit A.
See Cooling Service Analysis (Table 89).
See No Dehumidification Demand, below.
See CRC Relay Operation, below.
See RH1 Valve Operation, below.
See CV Valve Operation, below.
See Cooling Service Analysis (Table 89).
See No Dehumidification Demand, below.
See CRC Relay Operation, below.
See RH1 Valve Operation, below.
See CV Valve Operation, below.
See RH2 Valve Operation, below.
Check Reheat2 Circuit Limit Temperaturess
(Configuration→HMZR→RA.LO and RB.LO)
using ComfortLink™ Scrolling Marquee.
Check/reduce setting on accessory humidistat.
Check Space RH Setpoint (Setpoints→RH.SP)
using ComfortLink Scrolling Marquee.
Check Space Humidity Switch (Configuration→
UNIT→RH.SW) using ComfortLink Scrolling
Marquee.
Check RH Sensor on OAQ Input (Configuration→
UNIT→RH.S) using ComfortLink Scrolling
Marquee.
Check wiring. Check humidistat or humidity sensor.
Check using Cool→Reheat1 Valve Test
(Service Test→HMZR→CRC) using
ComfortLink Scrolling Marquee.
Check MBB relay output.
Check wiring.
Check transformer and circuit breaker.
Check wiring.
Replace faulty relay.
Check using Cool→Reheat1 Valve Test
(Service Test→HMZR→CRC) using
ComfortLink Scrolling Marquee.
Check CRC Relay Operation.
Check Wiring.
Check transformer and circuit beaker or fuses.
Check continuous over-voltage is less than 10%.
Check under-voltage is less than 15%.
Check for missing coil assembly parts.
Check for damaged valve enclosing tube.
Replace valve. Replace filter drier.
Check using Cool→Reheat1 Valve Test
(Service Test→HMZR→RHV.A or RHV.B)
using ComfortLink Scrolling Marquee.
Check MBB relay output.
Check wiring.
Check transformer and circuit breaker or fuses.
Check continuous over-voltage is less than 10%.
Check under-voltage is less than 15%.
Check for missing coil assembly parts.
Check for damaged valve enclosing tube.
Replace valve. Replace filter drier.
See CV Valve Operation, above.
See RH2 Valve Operation, above.
See Cooling Service Analysis (Table 89).
See RH2 Valve Operation, above.
See Cooling Service Analysis (Table 89).
See RH1 and CV Valve Operation, above.
Normal Operation During Mixed Circuit
Subcooling and Hot Gas Reheat Modes
at Lower Outdoor Temperatures.
None
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REMEDY