Airwell HAF 12, Руководство по обслуживанию

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12-5
CONTROL SYSTEM
SM HAFRPM 1-A.3 GB
12.4.5 Protections

High pressure protection is applicable to all operating modes.

Deicing control is valid in Heat and Auto Heat Mode only.

Defrosting control is valid in Dry, Cool, Heat and Auto Modes.

No reset after protection modes.
12.4.6 Thermistors operation

Return air Temp. is detected by RAT (RT1) in normal Mode, or by RCT (R/C sensor)
in I-FEEL Mode.

Indoor Coil Temp. is detected by ICT (RT2).
12.4.6.1 Definition of thermistor faults:
a. Thermistor is disconnected -
The thermistor reading is below -30 o c.
b. Thermistor is shorted -
The thermistor reading is over 75 o c.
c. Thermistor Temp reading doesn’t change (irrelevant for RT1) -
(i) This test is performed only once after a unit is switched from
OFF/STBY to operation. At the first occurrence of 10 min
continuous COMP operation, the current ICT & OCT are
compared with those when the COMP was switched from OFF
to ON 10 min before. If the

T is less than 3
o
c, the thermistor is
regarded as defective.
(ii) The ICT and OCT no-change error can be disabled together by
connecting a4.7 kohm resistor (5%) to the OCT connector. These
resistors are equivalent to a thermistor at 43+/-1
o c and 48+/-1 o c
respectively.
(iii) Connecting a 4.7k resistor to the ICT connector will disable the
ICT no-change error only.
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