Mitsubishi PKH-1.6GKLH Technical & Service Manual page 29

(4) Booster heater control [PKH-1.6GKLH, PKH-2GKLH]
When the room temperature is  degrees below the set temperature, the booster heater will turn ON.
When the room temperature is equal to the set temperature, booster heater will turn OFF.
During the hot adjustment, the booster heater will not work.
<Overheat prevention>
When the pipe temperature thermistor rises to 60°C or above, the booster heater cannot work.
When the pipe temperature thermistor falls to °C or below, the booster heater can work.
(5) Detecting abnormalities in the outdoor unit
When the outdoor unit is determined to be abnormal by the following causes, the compressor will stop and the check code "
P8 " will appear on the remote controller display.
( i ) During compressor ON while hot adjustment is set.
1 If the difference between the pipe temperature and room temperature is in the RANGE B
2 Within 20 minutes after entering RANGE B (except for the first 10 seconds),
a) If the temperature difference enters RANGE A, the hot adjustment starts,
b) If the temperature difference is still in RANGE B, the outdoor unit is deemed abnormal.
c) If the temperature difference enters RANGE C, defrosting starts.
3 Within 20 minutes after entering RANGE C, if the temperature difference does not return to RANGE B, the outdoor
unit is deemed abnormal.
4 If the temperature difference returns to RANGE B, the next 20 minutes is an allowance period. If the difference enter
RANGE A during the allowance, defrosting ends and the hot adjustment starts. If the difference does not enter
RANGE A during the allowance, the outdoor unit is deemed abnormal.
( ii ) During compressor ON in defrosting
After 0 minutes of defrosting in hot adjustment, if the temperature difference is still in RANGE C, the outdoor unit is
determined to be abnormal.
When RANGE B does not change to RANGE A after 20 minutes have passed since RANGE C had outdoor unit is deter-
mined to be abnormal.
( iii ) During compressor OFF
Not detecting abnormalities.
(6) Pipe temperature thermistor abnormality detection
An abnormality can be detected during compressor ON, except for the following.
● For the first 30 minutes after the temperature difference between the pipe temperature and room temperature enters the
RANGE C.
● When the temperature difference enters the RANGE C until it moves to the RANGE B.
(7) Defrosting operation
After the outdoor unit starts the defrosting operation, when the temperature difference between the pipe temperature and
room temperature gets out of RANGE A and into RANGE B, the indoor unit starts the defrosting mode. After the outdoor
unit stops the defrosting operation, when the temperature difference returns to the RANGE A, the indoor unit stops the
defrosting mode. While the indoor unit is in the defrosting mode, the indoor fan and the booster heater stop.
w1 RANGE A : Pipe temperature is more than  degrees above room temperature.
RANGE B : Pipe temperature is within  degrees either way of room temperature.
RANGE C : Pipe temperature is more than  below room temperature.
OC229A
Pipe temperature
minus room temperature
RANGE A
(degree)
+
0 RANGE B
-
RANGE C
29 29
w1
, the indoor fan will stop.