Diagnostics - Carrier 39HXC Manual

7 - FAULTS

7.5 - Diagnostics

Fault
Powered down
Fire protection
Frost protection
Intake EC motor
Exhaust EC motor
Intake air flow low limit
Extraction air flow low limit
Intake filter 1 fouled
Exhaust filter 1 fouled
Intake filter 1 blocked
Exhaust filter 1 blocked
Intake flow rate pressure
sensor
Extraction filter pressure
sensor
Intake flow rate pressure
sensor
Exhaust flow rate pressure
sensor
Heat recovery unit pressure
sensor
Rotary heat exchanger
Heat recovery frosted
Electric heater safety
thermostat
Intake duct pressure too low
Intake duct pressure too high
Exhaust duct pressure too low The duct pressure is below the fixed
Exhaust duct pressure too
high
Sources
The power supply has been cut
The "fire protection" contact has
been triggered
The supply air temperature sensor
detects a temperature below
threshold P248
(4°C by default)
An EC motor is indicating a fault
The air flow rate is below the fixed
limit P111
The pressure drop in the filter is
greater than the "filter fouled"
threshold
The filter pressure drop is greater
than the "filter blocked" threshold
The pressure sensor signal is less
than 0.5 V
The rotary heat recovery unit
indicates a fault
The pressure drops measurement
for the heat recovery unit is greater
345 Pa
One of the safety thermostats for an
electric heater has been tripped
The duct pressure is below the fixed
limit P124
The duct pressure is above the fixed
limit P125
limit P142
The duct pressure is above the fixed
limit P143
Causes
The circuit breaker has been
triggered
Voluntary stop
Triggered by the fume detector or by
the external fire contact managed by
the operator
The air temperature at the outlet for
the
1st hydraulic coil is too cold
Overvoltage, motor overload, motor
power supply problem, etc.
The air passage is blocked
The pressure measurement sensor
is defective
Constant pressure control: the
pressure drops in the network are
too great
The filter is dirty
The filter is blocked
The sensor is faulty
Incorrect connection
The heat recovery unit controller has
detected a fault
Operating problem with the
differential pressure sensor
The heat recovery unit is clogged
The heat recovery unit is frozen
The temperature in the electric
heater is greater than the thermostat
limit (80 °C)
Operating problem with the intake
pressure sensor
Operating problem with the FMAs
Operating problem with the intake
pressure sensor
Operating problem with the FMAs
Operating problem with the intake
pressure sensor
Operating problem with the FMAs
Operating problem with the intake
pressure sensor
Operating problem with the FMAs
Solutions
Check the wiring and the components
Empty
Check the condition of the contacts
Check the operation of the first coil:
valve jammed, no flow, no hot water, etc.
Check the condition of the intake
motor(s)
Check the condition of the exhaust
motor(s)
Check the pressure drops and ensure
there are no foreign bodies in the ducts
and
the unit
Check the operation of the sensor
Check the opening/closing of the duct
network dampers
Schedule replacement of the filter before
it becomes clogged
Replace the filter
Replace the sensor
Check the electrical connection and
tightness of the connections
Check the operation of the heat recovery
unit and the condition of the belt
Check the operation of the sensor
Clean the heat recovery unit
Wait for the heat recovery unit to be
defrosted
Check that the air flow is sufficient and
check the condition of the switches and
the electric heater
Check the operation of the sensor
Check the maximum frequency of the
inverter/motor and check that the motor
turns correctly
Check the operation of the sensor
Check the maximum frequency of the
inverter/motor
Check the operation of the sensor
Check the maximum frequency of the
inverter/motor and check that the motor
turns correctly
Check the operation of the sensor
Check the maximum frequency of the
inverter/motor
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