Operation Modes And Functions - North American HVAC MSC-28CRDN1-MN15W Service Manual

A weak current flow through the coil of compressor from the wiring terminal of compressor, then the
compressor is heated without operation.
----Preheating release condition:
If T4＞5℃ or the compressor starts running, preheating function will stop.
---- Heating cable
It starts when T4<5℃ and stops when T4>15℃
8.3.8 Zero crossing detection error protection
If AC detects time interval is not correct for continuous 20 zero crossing signal, the unit will stop and
the LED will display the failure. The correct zero crossing signal time interval should be between
6-13ms.
8.3.9 Sensor protection at open circuit and breaking disconnection

8.4 Operation Modes and Functions

8.4.1 Fan mode.
(1) Outdoor fan and compressor stop.
(2) Temperature setting function is disabled, and no setting temperature is displayed.
(3) Indoor fan can be set to high/med/low/auto.
(4) The louver operates same as in cooling mode.
(5) Auto fan:
The action of auto fan in fan-only mode is the same as auto fan in cooling mode with 24℃ setting
temperature.
8.4.2 Cooling Mode
8.4.2.1 Compressor running rules:
The operation frequency of compressor after starting submits to the following rule.
℃
27.5
High
27.0
25.5
Medium
25.0
Low
28