If the compressor accumulative running time over the setted value [HF05], one of the enter conditions is
b. Temp. difference condition between outdoor coil and outdoor ambient temp.
Outdoor coil temp. T
compressor, if set [HF02] parameter, defrost can be started when T
cancel, Outdoor coil temp. sensor and outdoor ambient temp. sensor are damage, this condition is
c. Outdoor coil temp. condition
Outdoor coil temp. condition is determined by [HF03] parameter. Deforst will not startup untill T
is meeted. If [HF02] and [HF03] are valid synchronously, enter defrost when both are meeted. If neither
[HF02] or [HF03] is cancelled or outdoor coil temp. sensor damage, enter defrost when time condition is
13.3.2 Multi units defrost simultaneously
If one unit of the modules meet the above single unit deforst enter conditions, other units will enter defrost
together and ignore the coil temp. condition.
13.3.3 Quit conditions for defrost
After entering defrost, running at least 3 minutes, then judge if deforst can be quited according to the
transformation of compressor pressure, coil temp. and deforst time, deforst can be quited if any one of the
conditions is meeted.
a. Quit deforst when compressor in high pressure
When compressor defrost and cause pressure rise, after high pressure switch open, the unit will quit
b. Outdoor coil temp.
When compressor defrost and cause outdoor coil temp. rise, when T
c. Time condition for quit deforst
[HF06] has been setted the longest time for deforsting, when deforst exceed the setted time [HF06],
deforst will quited no matter the outdoor coil has meeted the setted value [HF04] or not.
13.3.4 Quit condition for multi units defrost simultaneously
if there are other units defrost when one unit meet the quit conditions, the unit will stop and standby untill
all the units are quit seforst and then heating again.
13.3.5 Deforst procedure
[SA04] has setted two deforst procedure: when set [SA04] ON, compressor will change to defrost directly
without stop; when set [SA04] OFF, compressor will stop firstly and begain deforsting after 4-way valve has
will be lower than outdoor ambient temp. T
≥[HF04], the unit will quit defrost.
for the heating operation of
≥[HF02]. If [HF02] is setted