Daikin MicroTech Operation And Maintenance page 59

Can't Heat Alarm
Name: CantHeatAlarm
Description: The unit is trying to heat, but conditions do not
allow this (entering water temperature is too low to heat and no
other form of heating is available), or an ASHP has a call for
heating but the compressor is locked out because of low OAT,
or no flow to the compressor for WSHPs.
Type: Problem
Activate: All of the following are true:
• Heating is required
• Compressor heat is unavailable
• Entering water is too cold for hydronic heating
• Unit is not configured for electric heat
Upon active:
• Alarm is indicated on the LUI
• Fault relay is energized if alarm output configuration is
FAULTPROB
• LED output alarm indication is activated
Deactivate: Compressor heating becomes available or the
entering water temperature becomes warm enough to provide
heat.
Reset: Auto
Discharge Air Temperature Low Limit
Name: DATLLAlarm
Description: The discharge air temperature is below the
Economizer Low Limit setpoint and heating capacity is at 100%
for longer than the discharge air temperature low limit alarm
timer. This alarm can occur from any state except compressor
or hydronic cooling.
Type: Problem
Activate: Discharge air temperature < Discharge air
economizer low limit setpoint AND it's not in compressor or
hydronic cooling and all heat stager are on.
Upon active:
• State: Any non-cooling mode go to Low Limit State
— OA reduced
• State: Any cooling mode go to Reheat State
— Heating increased
• Fault relay is energized if alarm output configuration is
FAULTPROB
• LED output alarm indication is activated
Deactivate: Discharge air temperature >Discharge air
economizer low limit setpoint + 1.8°F and the outdoor air
damper position has returned to its calculated minimum
position.
Reset: Auto
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Brownout (Future)
Name: BrownoutAlarm
Description: 24VAC input voltage is more than 20% below
nominal.
Type: Problem
Activate: 24 VAC input voltage <= 80% nominal value.
Upon active:
• Compressor is immediately de-energized
• Fault relay is energized if alarm output configuration is
FAULTPROB
• LED output fault indication is activated
Deactivate: 24 VAC input voltage > 80% nominal value.
Reset: Auto
High Voltage (Future)
Name: HighVoltageAlarm
Description: 24VAC input voltage is more than 20% above
nominal.
Type: Problem
Activate: 24 VAC input voltage >= 120% nominal value.
Upon active:
• Compressor is immediately de-energized
• Fault relay is energized if alarm output configuration is
FAULTPROB
• LED output alarm indication is activated
Deactivate: 24 VAC input voltage < 120% nominal value.
Reset: Auto
Change Filter Indication
Name: ChangeFilterAlarm
Description: The indoor fan has been running for longer than
the filter change hours setpoint indicating that the filter may be
dirty:
Type: Warning
Activate: The software is configured to allow this alarm and
the filter runtime hours >= the filter change hours setpoint.
Upon active:
• Alarm is indicated on the LUI
Deactivate: Filter reset command is sent from the network or
LUI keypad.
Upon De-active:
• Set Filter Change Hours to 0
Reset: Auto.
59 OM 1280-2 • MICROTECH UNIT CONTROLLER
Diagnostics and Service