Fujitsu ASU30RLE Service Instruction page 30

5. LOW PRESSURE PROTECTION CONTROL (For Cooling mode)
5-1. Low Pressure Protection 1
<After the compressor start-up and 1 minute has passed>
(a).The detected value of pressure sensor is 17.4 psi(0.02MPaG) or less, continues for 5 minutes,
the compressor is stopped.
(b). When 7 minutes has passed and low pressure sensor detects value is more than 21.8 psi(0.05MPaG)
after the protection stop by (a), the compressor restarts.
(c).When the protection (a) operates 5 times within 2 hours after the restart by (b), the error is displayed
and the compressor stops. [Permanent stop]
( Fig. 19 : Low pressure protection 1 )
Pressure
21.8 psi(0.05MPaG)
17.4 psi(0.02MPaG)
5-2. Low Pressure Protection 2
<After the compressor start-up and 10 minutes has passed>
(a).When the low pressure value becomes ??? psi(0.68MPaG) or less continues for 1 minute,
the compressor speed -8 rps.
(b). When the low pressure value becomes ??? psi(0.68MPaG) or less after the protection (a), the compressor
continues speed -8 rps every 1 minute until the detected value becomes more than ??? psi (0.68MPaG).
(c). When the low pressure value becomes more than 0.78MPaG, this protection is released.
( Fig. 20 : Anti freezing protection )
Pressure
??? psi (0.78MPaG)
??? psi (0.68MPaG)
Release of protection
Hold
Compressor stop
Release of protection
Hold
-8 rps every 1 minute
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