Air Conditioner Service Manual
18
6. Defrost
Note: t1: compressor continuous works time.
t2: AC unit operation first time going to defrost circle.
t3: compressor accumulated working time (when OPT
≤3
℃
unit starts to count the time for t3).
When AC unit working to:
a. t1≥t2, or
b. t3≤t1
＜
t2.
and also the temperature (related to OAT & OPT) tested 3 min continuously meets for defrosting.
1)
Defrosting start up
: Compressor stops working, and re-starts to working after 50s delay;
2) Conditions for quitting defrosting
a. After defrosting 60s, and OAT≥12
℃
; or
b. OAT
＜－
5
℃
, and OPT ≥8
℃
for 80s continuously; or
c. The defrosting for 10 min.
When AC meet any of condition a, b or c, defrosting finish.
COMPRESSOR
ON
OUTDOOR FAN
4-way VALVE
OFF
50S
50S
43S
48S
Defrosting max time
43s
3)
Defrosting end off
: Compressor stops working, and re-starts to working after 50s delay;
7. Cold air prevention:
This function intends to prevent cold air from being discharged when the heating operation starts up
1). IDU fan motor cold air prevention
①
.When RT
＜
24
℃
:
a. If ITP
＞
31
℃
while compressor works for 5 min, fan motor will work according to preset fan speed.
b. If IPT≤31
℃
, fan motor stops working while compressor operation within 2min, if IPT≥27
℃
, fan motor works in
low speed 2 min, then change to preset speed.
②
When RT≥24
℃
:
a. Within 2 min after compressor start up working, once IPT
＞
27
℃
, fan motor will change to preset speed.
b. After compressor starts working 2 min, fan motor change to preset speed directly.
2). Vane blade operation for cold air prevention.
a.
If the vane works on status of
non-swing
: While IPT increase to a special degree, the vane blade will change
the position to:
①
Default angle; or
②
Previous position; or
③
Customer preset.
The above operation can work one time only, when compressor stops working, the unit will once again inspect
the function.
b.
If the vane works on
swing
: When IDU quits from cold air prevention, vane operate as preset.
8. “8
℃
” Heating
When function effective, it will make sure the room temperature not lower than 8
℃
, unit works on heating mode.
