Unit Description
36
Engine, Continuous Run—Single
Compartment Operation
Zone 1 Evaporator: At setpoints above 15 F
(-9.4 C), the Zone 1 evaporator operates in the
following modes.
• Cool
• Heat*
• Defrost
At setpoints below 15 F (-9.4 C), the Zone 1
evaporator operates in the following modes.
• Cool
• Heat*
• Defrost
*Null if the Zone 2 evaporator is in Defrost.
Zone 2 Evaporator: At setpoints above 15 F
(-9.4 C), the Zone 2 evaporator operates in the
following modes.
• Cool
• Null
• Heat
• Defrost
NOTE: During single compartment operation,
the Zone 2 evaporator is controlled by the Zone 1
thermostat.
At setpoints below 15 F (-9.4 C), the Zone 2
evaporator operates in the following modes.
• Cool
• Null
• Defrost
0. Setpoint
1. Temperature Drop
2. Temperature Rise
3. Cool—Force Condensing Unit to High Speed
4. Cool
5. Heat (Null if Zone 2 Evaporator is in Defrost)
6. Heat—Force Condensing Unit to High Speed
(Does not Force Condensing Unit to High
Speed if Setpoint is below 15 F [-9.4 C]. Null if
Setpoint is Below 15 F [-9.4 C] and Zone 2
Evaporator is in Defrost)
Figure 7: Zone 1 Evaporator Engine, Continuous
Run, Single Compartment Control Algorithm
0. Setpoint
1. Temperature Drop
2. Temperature Rise
3. Cool
4. Null
5. Heat (Null if Setpoint is Below 15 F [-9.4 C])
Figure 8: Zone 2 Evaporator (Engine Set on
Continuous Run) Single Compartment Control
Algorithm