Fujitsu AMUG24LMAS Service Manual page 134

AOUG36LMAS1
AOUG48LMAS1
Normal defrost
Ta > = 14 F(-10 C) 4 F(-20 C) < = Ta <14 F(-10 C) Ta > = 4 F(-20 C) Tn = 21.2 F(-6 C)
<
< ° ° Tn = 0.8xTa-11.6
Tn = 1.4 F(-17 C)
< =
Tn -18.4 F(-28 C)
Tn : Outdoor heat-exchanger temperature.
Ta : Outdoor temperature.
Tn-1 : Before 5 minutes detected Tn.
Sn : Number of operation indoor units.
Sn-1 : Before 5 minutes detected Sn.
Heating operation start : Compressor ON
<
Tn = 0.8xTa-11.6
or
or
° °
< = °
Tn -18.4 F(-28 C)
Outdoor heat exchanger temperature : Over 59
Compressor ON time : Maximum 15 minutes
<
Tn-Tn-1 < 28.4 F(-2 C)
° °
and Sn=Sn-1
°
Defrost start
Defrost Indicator:
[Operation lamp]
7 sec ON / 2 sec OFF
3 sec. later Compressor : OFF
3 sec. later Outdoor fan motor : OFF
35 sec. later 4-way valve : OFF
41 sec. later Compressor : ON
or
Defrost end
04-27
Integrating defrost Integrating defrost
(Integrating OFF count defrost)
More than 210 minutes
(For continuous operation)
Compressor OFF
Tn < 26.6 F(-3 C) ° °
(and after 30 minutes, count : 40 times
if the Tn < 26.6 F(-3 C) ° °
(Less than 10 minutes)
or
Tn < 23 F(-5 C)
° °
(and after 3 minutes,
if the Tn < 23 F(-5 C)
° °
° F(15°C)