General Functions
SiBE04-101
38
Main Function
1.174-Way Valve Function Compensation
Outline
When the initial start of compressors is required after power is on or at operation mode’s alteration
(Cooling/Dry
↔
Heating) that the a switch-over of a 4-way valve takes place, it secures the necessary
differential pressure by restricting the operation frequency in the lower limit in a certain period, and the
switch-over action is ensured.
Caution
To avoid the temperature rise of the 4-way valve coil, the 4-way valve coil is energized in heating
operation.
Details of the
Control
1. If a 4-way valve is OFF when compressors stop, it will be ON at this time.
2. If a 4-way valve was ON when compressors operated in the last time, it will be ON at this time.
3. At the start of compressors.
4. At the initial start of compressors after power is reset.
In case 1. and 3. are under the simultaneous condition of AND (it indicates Heating) or 2. and 3 are under
the simultaneous satisfaction of AND (it indicates Cooling), or condition 4. is adapted, the processing
applies A seconds after compressors begin operating and to set B Hz for the lower limit of operation
frequency.
A (sec)
B (Hz)
Cooling
50~71 Class
60
56
Heating
50 Class
60
56
60 Class
60
42
71 Class
60
32
SiBE04-101.book Page 38 Monday, October 15, 2001 3:08 PM