28                         Specifications subject to change without notice.                                                       38MGR-04SM
Heating Mode
Fig. 33 — Heating Mode
Table 28 — Heating Mode 
Table 29 — Heating Mode 
NOTE: The final result is an integer.
Modify the result according to a T2 average (correction).
NOTE: Average value of T2; sum of T2 value of all indoor
units)/(indoor units number).
Fig. 34 — T2 Average
Use Table 30 and the final capacity request to confirm the operating
frequency.
Table 30 — T2 Average 
The maximum running frequency is adjusted according to the outdoor
ambient temperature.
Fig. 35 — T2 Average
Defrosting Control
Defrosting Conditions
After the compressor starts and enters a normal operation, mark the
minimum value of T3 from the 10th to the 15th minute as T30.
If any one of the following conditions is satisfied, the unit enters the
Defrosting mode:
1. If  the compressor’s cumulative  running  time  reaches  29  minutes
and T3<TCDI1 and T3+T30SUBT3ONE ≦T30.
2. If the compressor cumulative running time reaches 35 minutes and
T3< TCDI2 and T3+ T30SUBT3TWO≦T30.
3. If the compressor cumulative running time reaches 40 minutes and
T3<
24°C for 3 minutes.
4. If the compressor cumulative running time reaches 120 minutes and
T3<
15°C.
Defrost Stop Conditions
If any of the following conditions is satisfied, defrosting ends and the
unit returns to the normal heating mode:
....T3 rises above than TCDE1°C
....T3 remains at TCDE2°C or above for 80 seconds
....Unit runs for ten consecutive minutes in DEFROSTING mode
Defrosting Actions
Fig. 36 — Defrosting Action
Capacity Area a b c d e f
Norm code (N) 3 2 1.5 1 0.5 0
Model 9K 12K 18K 24K
HP 1.0 1.2 1.5 2.5
Frequency 
(Hz)
0 HEAT_F1 HEAT_F2
...
...
HEAT_F24 HEAT_F25
Amendatory
Capacity 
Demand
0 1 2
...
...
24 25
T1 Ts
Decrease frequency
Keep frequency
Increase frequenc
 no īo
Cool-F9 
10S 30S
TimeA
10S
compressor 
Indoor fan 
Outdoor fan 
EXV open 
frequency 
Max 10 minutes 
frequency 
Compressor stops 
oī 
oī 
 s042 rof P084 P084