Faults - Daikin DPS Installation And Maintenance Manual

Interface Board Communication
Problem – (IFB Comm: Problem)
This alarm occurs when a communication problem is detected
at any of the communication connections to the IFB board .
When this alarm is active compressor cooling and heating
operation are generally disabled .
The alarm normally is cleared automatically when the
communication problem is corrected . If the alarm occurs for a
fifth time in a 24 hour period it must be manually cleared once
corrective action is taken .
Low Refrigerant Pressure Differential
Problem – (Lo Press Diff: Problem)
This alarm occurs when the Low Differential Pressure
Unloading function has forced compressor operation to the
Standby state for a third time in a 30 minute period .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
Low Refrigerant Pressure Problem – (Lo
Press 1: Problem)
This alarm occurs when either the Cooling Low Pressure
Unloading or the Heating Low Pressure unloading function has
forced compressor operation to the Standby state for a third
time in a 30 minute period .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
High Refrigerant Pressure Problem – (Hi
Press 1: Problem)
This alarm occurs when either the Cooling High Pressure Unloading or
the Heating High Pressure unloading function has forced compressor
operation to the Standby state for a third time in a 30 minute period. This
alarm also occurs if either of the mechanical high pressure switches (HP1
or HP3) open.
When this alarm is active compressor cooling and heating operation are
disabled.
The alarm must be manually cleared once corrective action is
taken
OM 1141-3 • MICROTECH UNIT CONTROLLER
High Inverter Compressor Body
Temperature – (HiINVCmpT: Problem)
If the inverter compressor body temperature rises above
245°F continuously for 5 seconds or 230°F for 10 minutes,
the inverter compressor is shut down . After remaining in the
standby for restart state for one cooling stage time period the
compressor is allow to restart . If this occurs three times in a
100 minute time period, the High Inverter Compressor Body
Temperature problem occurs . The cooling will then remain off
until this alarm is manually cleared through the unit keypad or
via a network signal .
Inverter Compressor Body Temperature
Sensor Problem – (INVCmpTSnsr:
Problem)
If the inverter compressor body temperature sensor becomes
shorted or open circuited or out of range for longer than the
Sensor Alarm Delay (Default= 30 seconds) . When this alarm is
active compressor cooling and heating operation are disabled .
The alarm must be manually cleared once corrective action is
taken .

Faults

Airflow Fault - (Airflow: Fault)
Fan Retry
On units configured for variable volume supply fan, the Fan
Fail fault only occurs if the fan retry condition described below
has first occurred twice within the previous twenty-four hour
period . The conditions that cause the fan retry, and the action
taken, are the same as for the Fan Fail fault with the difference
being that the fan retry condition is automatically reset once
the unit is shut off . This allows the unit to attempt to restart, up
to three times within a twenty-four hour period .
The Fan Retry conditions are:
• No Faults that would shut down the unit are active
• Airflow Switch is Open AND the duct static pressure is
less than half of the Duct Static Pressure Set Point . If
Modbus communication is lost between the MCB and the
supply fan the duct static pressure is not considered in
the Fan Fail logic .
• The Supply Fan has been on for longer than the Airflow
Timer (Default =120 seconds)
• The unit is not in Post Heat Operation and has not been
in Post Heat Operation for longer than 120 seconds . This
means that fan retry is disabled during and after post heat
operation
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