Operating Instructions

APOGEE Heat Pump Controller—Multi-Stage Owner's Manual
Power Failure Recovery
Upon return from a power failure, the heating and cooling compressors are kept off, the
electric heat (if used) is kept off and the fan is kept off. In addition to the equipment being
OFF, both cooling and heating loops are set to 0. This situation will remain in effect until the
power failure recovery period for this controller is over.
The controller returns to normal control when its power failure recovery period is over. The
power failure recovery time for a heat pump is based on the following formula:
RETURN DELAY + (CTLR ADDRESS × 10 seconds)
This lessens the demand of having all the electrical equipment starting at once.
Centralized Alarm Monitoring
DI 4 can be used to monitor an input that changes state when the heat pump is in alarm.
DI 4 can be unbundled to send alarm information to the field panel for centralized alarm
monitoring.
Overriding DOs
Heat Pump applications allow spare DOs, damper (DO1 and DO2) and electric heat stages
(DO3, DO6 and DO7 when applicable) to be commanded.
The fan (DO8), reversing valve and compressor(s) (DO4 through DO7) cannot be directly
commanded ON or OFF. This is done to prevent damage to the mechanical equipment.
Fail-safe Operation
If the RTS or the setpoint dial fails, the controller operates using the last known temperature
value.
Using Auxiliary Points
lt is possible to have extra points available on a Heat Pump Controller—Multi-Stage in
addition to the ones used by the current application that is running in the controller. If these
extra points will be controlled by a field panel, they must be unbundled at the field panel.
10 Siemens Building Technologies, Inc.