Daewoo FRS-U20DD. Service Manual page 44

8-8-2. Inverter Control Mode
1) Frequency Mode
Controls the compressor speed through a frequency signal sent to the Inverter.
The frequency signal is a digital square wave, with 0 to +5V voltage amplitude and defined range as described ahead.
The duty cycle must be from 30% to 70%.
2) Compressor speed
Compressor speed will follow the frequency signal, according to the relation described bellow.
Input Signal Comp Speed
(Hz) (rpm)
0 to 50 0
50.1 to 53.3 1,600
53.4 to 150 30 x Hz
105 to 111 hysteresis
130 to 132 hysteresis
136.6 to 138.6 hysteresis
> 150 4,500
< Relation between Inverter frequency and compressor rotation >
3) In this refrigerator, input frequency signals are used as below.
Ambient Temperature
over 35℃
below 35℃
< Frequency signal >
Condition
Other conditions
-
Normal condition
Initial Power connected
Weak-Cool
Super FRZ
Super REF
Input
Frequency
122 Hz
85 Hz
122 Hz
44
Comp Speed
3660 rpm
2550 rpm
3660 rpm