Service manual

Si04-115 General Functionality
Main Function 39
1.18 Wet Operation Protection
Outline The lower limit of output frequency is limited in two steps in accordance with outdoor conditions
in order to secure the reliability of compressor (suction dryness and differential pressure).
Processing 1. at the first step
 During operation of compressors.
 Outdoor temperature
≤
DOA1CG
"
If  and  are under the simultaneous condition with AND, the lower limit of frequency in
this function is set at FCG7.
 Compressors stop.
 Outdoor temperature
≥
DOA2CG
"
If  and  are under the simultaneous condition with OR, the lower limit of frequency at the
first step control is cancelled.
2. at the second step
 During operation of compressors
 Outdoor temperature
≤
DOA3CG
"
If  and  are under the simultaneous condition with AND, the lower limit of frequency in
this function is set at FCG8.
 Compressors stop.
 Outdoor temperature
≥
DOA4CG
"
If  and  are under the coordinate condition with OR, the lower limit of frequency at the
second step control is cancelled.
3. The set of a constant
DOA1CG, DOA2CG, DOA3CG, FCG7 and FCG8 have constants for Cooling /Heating
separately and these constants are distinguished with a suffix c/w.
4. Actual constant
∗
DOA : Outdoor air temperature
CGC : Compressor guard for cooling
CGW : Compressor guard for heating
FCG : Frequency guard for compressor protection
(In cooling)
J type 25 / 35
(In heating)
J type 25 / 35
DOA1CGC 18°C DOA1CGW 0°C
DOA2CGC 20°C DOA2CGW 2°C
DOA3CGC 14°C DOA3CGW -4°C
DOA4CGC 16°C DOA4CGW -2°C
FCG7C 34Hz FCG7W 48 Hz
FCG8C 34 Hz FCG7W 54 Hz
FCG8
The lower frequency limit.
Cancelled FCG7 FCG7
DOA3CG
DOA4CG
DOA1CG
DOA2CG
Outdoor temperature
(R1922)