Carrier 42QHC009DS Service Manual page 23

T3
TP3+5
TP3
TP3-3
---TP3<T3< TP3+5, the compressor frequency
will decrease to the lower level until to F1 and
then runs at F1.If TP3-3<T3< TP3, the
compressor will keep running at the current
frequency.
---T3< TP3-3, the compressor will not limit the
frequency and resume to the former frequency.
---T3> TP3+5 for 5 seconds, the compressor
will stop until T3< TP3-3.
8.4.2.5 Evaporator temperature protection
When Evaporator temperature temp.is less
than setting value, the compressor will stop.
8.4.3 Heating Mode
8.4.3.1 Compressor running rules
When T1-Ts>-ΔT, the compressor will stop,
<ΔT-1.5， the compressor will be on.
when T1-T
S
ΔT is the programmed parameter of
temperature compensation.
When the AC run in mute mode, the
compressor will run with low frequency.
When the current is more than setting value,
the current protection function will be activated
and the compressor will stop.
8.4.3.2 Outdoor fan running rules
The outdoor unit will be run at different fan
speed according to T4.
For different outdoor units, the fan speeds are
different.
Off
Decrease
Hold
Resume
T4
A+
A
B
C
D
E
8.4.3.3 Indoor fan running rules
When the compressor is on, the indoor fan can
be set to high/med/low/auto. And the anti-cold
wind function has the priority.
The indoor fan is controlled as below:
Setting fan
T1-Td ℃(° F)
speed
H
M
L
Auto fan action in heating mode:
T1
a
b
8.4.3.4 Defrosting mode
AC will enter the defrosting mode according to
the value of temp. of T3 and the value range of
temp. change of T3 and also the compressor
running time.
During the defrosting mode, the compressor keep
running, indoor and outdoor motor will stop,
defrost lamp of the indoor unit will be lighted
"
." Will be displayed.
If any one of the following items is satisfied, the
defrosting will finish and the machine will turn to
21
Actual fan speed
H+(H+=H+G)
A H（=H）
B
H-（H-=H-G)
C
M+(M+=M+Z)
D M(M=M)
E
M-(M-=M-Z)
F
L+(L+=L+D)
G L(L=L)
H
L-(L-=L-D)
I
c
d
e