Daikin MicroTech III DPS Installation And Maintenance Manual page 41

Defrost Temperature Sensor Problem (Heat
Pump only) – (DFT Sensor: Problem)
This alarm occurs when the DFT sensor input is shorted or open
circuited for the Sensor Alarm Delay (default 30 seconds) . It can
also occur if the input is outside the range of -47°F to 194°F .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
Suction Line Refrigerant Temperature Sensor
Problem – (SRT Sensor: Problem)
This alarm occurs when the SRT sensor input is shorted or open
circuited for the Sensor Alarm Delay (default 30 seconds) . It can
also occur if the input is outside the range of -47°F to 194°F .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
High Inverter Compressor Discharge Line
Temperature Problem – (Hi DL Temp: Problem)
This alarm occurs when the High Discharge Line Temperature
Unloading function has forced compressor operation to the
Standby state for a third time in a 100 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 .
Expansion Valve Problem – (Exp Valve:
Problem)
This alarm occurs when the IFB communication board detects
a faulty or disconnection between an expansion valve (EVI or
EVO) and the expansion valve control board (EVB) .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
NOTE: The EVB only detects a change in the EVI or EVO
condition upon power up of the EVB .
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Outdoor Fan Problem – (OA Fan: Problem)
On a single outdoor fan unit this alarm occurs when compressor
operation is forced to the Standby state due to an outdoor fan
internal fault for a third time in a 30 minute period .
On a two outdoor fan unit this alarm occurs when compressor
operation is forced to the Standby state due an outdoor fan 2
internal fault for a third time in a 30 minute period . Note that
outdoor fan 2 in this configuration provides critical cooling for the
inverter/outdoor fan control boards .
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 Charge Problem – (Lo Charge:
Problem)
During compressor cooling operation this alarm occurs when the
indoor expansion valve (EVI) is fully open (greater that 95%),
the super heat is well above set point (greater than 20°F) and
the lower of the two discharge line temperature inputs (DRT1
and DRT3) is hot (greater than 150°F) for more than 30 minutes
continuously .
During compressor heating operation this alarm occurs when the
outdoor expansion valve (EVO) is fully open (greater that 95%)
and the super heat is well above set point (greater than 20°F) for
more than 60 minutes continuously .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
Refrigerant Charge Loss Problem –
(ChargeLoss: Problem)
This alarm occurs when both the suction and discharge
line pressure inputs (PTS and PTD) remain below 10 psi
continuously for 5 seconds .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
Suction Line Refrigerant Pressure Sensor
Problem – (PTS Sensor: Problem)
This alarm occurs when the suction line pressure inputs (PTS)
remains above 256 psi continuously for 12 minutes or below -15
psi continuously for 10 seconds .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
41 OM 1263 • MICROTECH UNIT CONTROLLER
Alarms