Various Protections - Fujitsu ASU18RLQ Service Instructions Manual

21. VARIOUS PROTECTIONS

(1). DISCHARGE GAS TEMPERATURE OVERRISE PREVENSION CONTROL
The discharge gas thermosensor (discharge thermistor : Outdoor side) will detect discharge gas
temperature.
When the discharge temperature becomes higher than Temperature ,the compressor frequency
is decreased 20 Hz, and it continues to decrease the frequency for 20 Hz every 120 seconds until
the temperature becomes lower than Temperature .
When the discharge temperature becomes lower than Temperature ,the control of the control of the
compressor frequency is released.
When the discharge temperature becomes higher than Temperature
and the indoor unit LED starts blinking.
(Table 15 : Discharge Temperature Over Rise Prevension Control / Release Temperature)
Temperature
ASU15RLQ
ASU18RLQ
Temperature
ASU15RLQ Ta+165°F (74°C)
ASU18RLQ Ta+165°F (74°C)
(2). CURRENT RELEASE CONTROL
The compressor frequency is controlled so that the outdoor unit input current does not exceeds
the current limit velue that was set up with the outdoor temperature.
The compressor frequency returns to the designated frequency of the indoor unit at the time
when the frequency becomes lower than the release value.
(Table 16 : Current Release Operation Value / Release Value)
[ Heating ]
OT : Outdoor Temperature
ASU15/18RLQ
OT (Control / Release)
7.0A / 6.5A
63°F(17°C)
9.0A / 8.5A
54 °F(12°C)
10.5A / 10.0A
41 °F(5°C)
12.0A / 11.5A
[ Cooling / Dry ]
ASU15/18RLQ
OT (Control / Release)
4.5A / 4.0A
115 °F(46°C)
6.0A / 5.5A
104 °F(40°C)
8.5A / 8.0A
Temperature
219°F(104°C) 214°F(101°C)
219°F(104°C) 214°F(101°C)
Temperature
Ta+160°F (71°C)
Ta+160°F (71°C)
OT : Outdoor Temperature
Temperature
230°F(110°C)
230°F(110°C)
Temperature
*Outside temperature is E/F zone with
Ta+176°F (80°C)
within start 20 minutes in cooling mode.
Ta+176°F (80°C)
05-17
,the compressor is stopped