Frequency Range Of Start,Stop,And Operation (For Dc Inverter Scroll Compressor); Oil Return Control - Fujitsu Airstage V series Service Manual

4-2-3 Frequency range of start, stop, and operation
(For DC inverter scroll compressor)
On stop mode : 0 Hz
On operating mode : 30 - 94Hz
Frequency limit of after starting : After starting, frequency of
the compressor makes the shift to the target frequency after
holding 60Hz in operation frequency for a while.
Holding time at 60Hz is as follows.
Target frequency < 60Hz : Holding time is 30 sec.
Target frequency
* Upon 60sec hold, if the difference between discharge temperature
sensor and the high pressure saturation temperature that was
calculated from high pressure sensor detection value is higher than
10degC, the capacity is increased by 2Hz/60sec toward the upper
limit frequency.
And if Discharge SH becomes less than 4degC during operation, the
similar limit control same as 40Hz is applied. (Oil rise prevention)
It is same as the start up control, but the highest limit frequency is
different.

4-2-4 Oil return control

When the compressor operates, SV8 is turned on automatically.
When inverter is running, oil return valve of inverter always opens.
60Hz : Holding time is 60 sec.*
60Hz
0
04-03
60sec.
Hold
Target
frequency
30sec.
Time