OM 1263 • MICROTECH UNIT CONTROLLER 40 www .DaikinApplied .com
Alarms
Alarm Clearing
Active alarms can be cleared through the keypad/display .
Alarms are automatically cleared when power is cycled . Alarms
are cleared only if the conditions required to initiate the alarm
do not exist . All alarms and groups of alarms can be cleared
via the network or keypad by setting the ClearAlms variable to
a non-zero value as indicated in the table below. Emergency
Off Faults can be set to automatically clear once the condition
that caused the alarm is corrected . This can be accomplished
by navigating to Commission Unit/Alarm Configuration/Emerg
Stop and changing the default ManClr value to AutoClr .
NOTE:
The enumeration text is what shows up on the
keypad/display not the number . The value of this
variable automatically reverts to zero when the
alarms are cleared . This variable may be set through
the keypad in the Active Alarm menu . It may be set
via LON using nviClearAlarms and via BACnet using
the ClearAlarms object .
Alarm List Menu – see page 33.
Table 33: Alarm Clearing
Value
Action
0
None
1
Clear All Faults
2
Clear All Problems
3
Clear All Warnings
4
Clear All Alarms
Problems
OAT Temperature Sensor Problem - (OAT
Sensor: Problem)
If the outside air temperature sensor (OAT) is present, a valid
OAT value is not provided via the network and the local OAT
sensor is either shorted or open circuited for longer than the
Sensor Alarm Delay (default is 30 seconds), the Outside
Air Sensor problem occurs . When the OAT Sensor problem
occurs, the unit continues to operate with the following
modifications:
• Compressor heating and cooling operations are locked out .
• Cooling Reset and Heating Reset revert to none if they
are set to OAT
•
Economizer is locked out due to high OAT
When the alarm condition is no longer present, the OAT Sensor
problem automatically clears .
Indoor Refrigerant Temperature Sensor
Problem (Heat Pump only) – (IRT Sensor:
Problem)
This alarm occurs when the IRT sensor input is outside the range
of -4°F to 150°F continuously for the Sensor Alarm Delay (default
30 seconds) . When this alarm is active compressor heating
operation is disabled if HtgEVIMethod is set to “Sbc” . Otherwise
not action is taken . The alarm must be manually cleared once
corrective action is taken .
Outdoor Refrigerant Temperature Sensor
Problem (Heat Pump only) – (ORT Sensor:
Problem)
This alarm occurs when the ORT sensor input is outside the
range of -4 to 150°F continuously for the Sensor Alarm Delay
(default 30 seconds) .
When this alarm is active compressor cooling operation is
disabled if ClgEVOMethod is set to “Sbc” . Otherwise not action
is taken .
The alarm must be manually cleared once corrective action is
taken .
Fixed Speed Compressor Discharge Line
Refrigerant Temperature Sensor Problem –
(DRT3 Sensor: Problem)
This alarm occurs when the DRT3 sensor input is shorted or open
circuited for the Sensor Alarm Delay (default 30 seconds) . It can
also occur when the fixed speed compressor is off and the input is
above 329°F or the compressor has been off for 20 minutes and
the input is below -4°F .
When this alarm is active the fixed speed compressor is disabled.
The alarm must be manually cleared once corrective action is
taken .
Inverter Compressor Discharge Line
Refrigerant Temperature Sensor Problem –
(DRT1 Sensor: Problem)
This alarm occurs when the DRT1 sensor input is shorted or open
circuited for the Sensor Alarm Delay (default 30 seconds) . It can
also occur when the inverter compressor is off and the input is
above 329°F or the compressor has been off for 20 minutes and
the input is below -4°F .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .
Inverter Compressor Problem – (INV Comp:
Problem)
This alarm occurs whenever the inverter compressor board
generates an internal fault code . Refer to the troubleshooting
section of this document for fault code details .
When this alarm is active compressor cooling and heating
operation are disabled .
The alarm must be manually cleared once corrective action is
taken .