Danfoss AK2-SC 255, Reference Manual, Page: 138 / 206

RS.8D.M1.22 AK2-SC 255 Reference Manual 137
RTC alarms The following are alarms that appear uniquely for RTC systems, which also have
alarms similar to those just presented:
Zone hum fail
A digital alarm that can be enabled to occur when a zone humidity sensor failure is
detected by the RTC for a time period specified in the alarm (1-9999 seconds, min-
utes, or hours).
Zone temp fail
A digital alarm that can be enabled to occur when a zone temperature sensor failure is
detected by the RTC for a time period specified in the alarm (1-9999 seconds, min-
utes, or hours).
Supply temp fail
Similar to the preceding alarm.
Sensor discard (if control based on two or more zone sensors)
Occurs at the specified time after one of the controlling sensors fails and the control-
ler logic stops using the value of that sensor. The time setting can be from 1 to 9999
seconds, minutes, or hours. NOTE: if all zone sensors fail, control will be based on the
return air sensor.
Power failure
A digital alarm that can be enabled to occur whenever power is restored (after being
interrupted); the specified time period is (0-9999 seconds, minutes, or hours).
Filter (elapsed)
Occurs when the set number from 1 to 9999 seconds, minutes, or hours have elapsed.
Useful when set for the system air filter life as a reminder to change the filter.
Filter (runtime)
Occurs when the set number from 1 to 9999 seconds, minutes, or hours have elapsed.
Usually used Useful when set for the system air filter life as a reminder to change the
filter.
Sensor discard (if control based on two or more zone sensors)
Occurs at the specified time after one of the controlling sensors fails and the control-
ler logic stops using the value of that sensor. The time setting can be from 1 to 9999
seconds, minutes, or hours. NOTE: if all zone sensors fail, control will be based on the
return air sensor.
Power failure
A digital alarm that can be enabled to occur whenever power is restored (after being
interrupted) interrupted the inverter is in bypass for a specified time period (0-9999
seconds, minutes, or hours).
ClimaTECH alarm
configuration
Alarm types for the two ClimaTECH HVAC controllers are the same, and all are
embedded with a common time delay (which you can change) except the fire stat
alarm (the fire stat is wired to an AKC 55 digital input board, not to the ClimaTECH
controller; it is broadcast to the ClimaTECH over the AKC 55’s I/O network. The
alarm configuration screen for a ClimaTECH controller is shown below: