Carrier 42NQV009E Service Manual page 29

(4) Louver control
The vertical air flow louvers are automatically set
to horizontal or cool memory position.
When temperature of indoor heat exchanger
becomes 5° C or lower by the prevent-freezing
control and the compressor is turned off, the
vertical air flow louvers close once and then return
to the position of previous time.
(5) Discharge temperature control
(Common contr ol to cooling and heating)
The discharge temperature of refrigerant gas from
the compressor is detected by the discharge
temperature sensor, and controls operating
compressor motor speed.
1) Control 1 (A zone) : Normal operation zone
When TD detect value is 98° C or lower, the
operation is performed with operating motor
speed instructed by the serial signal.
2) Control 2 (B zone) : Slow-up zone of motor
speed
When TD detect value is 98° C or higher,
operating motor speed is slowly up.
3) Control 3 (C zone) : Keep zone
When TD detect value is 105° C or higher,
operating motor speed is not changed if raising
operation speed.
4) Control 4 (D zone) : Slow down zone of motor
speed.
When TD detect value is 108°C or higher,
operating motor speed is slowly down.
temperature is changed also.
5) Control 5 (E zone) : Nornal down of motor
speed.
When TD detect value is 112°C or higher,
operating motor speed is down.
6) Control 6 (F zone) : Operation stop zone
If TD detect value exceeds 117°C during
operation, stop the operation immediately.
Then, restart the operation when TD detect
value becomes 105°C or lower.
TD
Zone
(°C)
F
117
E
112
D
108
C
105
B
98
A
Fig. 8-2-2 Compressor motor speed control
(7) ECONO operation control
When the [ECO] button is pushed, ECONO
operation is performed by restraining air flow
and compressor motor speed. The set
temperature is changed also.
1) The set temperature increased 0.5°C per hour up
to 2°C starting from the set temperature when
ECONO has been received.
2) Indoor air flow is controlled between L + and UL.
The compressor motor speed in control as shown
in Fig. 8-2-3
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
− 28 −
FILE NO. SVM-07018
Operation stop zone
Normal down zone
of motor speed
Release of
motor speed
Slow down of
motor speed
Keep zone :
Motor speed is not changed.
Slow-up zone of motor speed
Normal operation zone
Compressor motor speed
Indoor
Fan
38YVE009 38YVE012
L+
32 rps 40 rps
22 - 32 rps 22 - 40 rps
L
L-
22 rps 22 rps
UL
OFF
Fig. 8-2-3