Other Control; Outdoor Unit Rotation; Sequence Of Outdoor Unit Rotation; Timing Of Outdoor Unit Rotation - Carrier 38VMA Series Service Manual

5. Other Control

a. Outdoor Unit Rotation
In the case of modular systems, the outdoor unit rotation is used to prevent the compressor from burning out due to unbalanced oil
level between compressors.
b. Sequence of Outdoor Unit Rotation
In the case of modular systems, each outdoor unit is given an operating priority.
Outdoor unit rotation makes it possible to change the operating priority of outdoor units. With the outdoor unit rotation control,
the system ensures that every outdoor unit has equal run hour making sure the oil is balanced between the individual outdoor unit.
c. Timing of Outdoor Unit Rotation
After oil return operation, after defrosting operation, or at system startup.

6. Cooling Operation Prohibition

Cooling operation is prohibited above 131⁰F ambient temperature.
Cooling operation is prohibited below 5⁰F ambient temperature.

7. Heating Operation Prohibition

Heating operation is prohibited above 77⁰F ambient temperature.
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