12-4
CONTROL SYSTEM
SM HAFRPM 1-A.3 GB
12.4
General
functions
12.4.1
COMP
operation
For each Mode including POWER OFF & SB, a Min time delay of 3 min
before COMP restarting, excluding DEICING Mode
The Min operation time of COMP under different operating conditions is
Operation Mode
Min operation time of
COMP
Heat, Cool or Auto Modes
3 min.
Fan, Dry, Overflow, Protection modes, or mode change
ignored
12.4.2 IFAN
operation
Min time interval between IFAN speed change in AUTOFAN Mode, is 30 sec.
Min time interval between IFAN speed change in H/M/L Mode is 1 sec.
IFAN speed in Heat/Cool Autofan Mode is determined according to the following table:
T
IFAN Speed
T
2
HIGH
2
T
1
MED
1
T
LOW
where in Heat Mode:
T = SPT-RT
in Cool Mode:
T = RT-SPT
Note:
In Heat Mode, the rules in section 4.0.3 have the higher priority.
The table above can be represent by a hysteresis curve which
will minimize the switching of the IFAN relay and will minimize the
change in IFAN speed:
T [
o
c]
L
M
H
IFAN speed
3
2
1
12.4.3 OFAN
operation
Min time interval between OFAN ON/OFF state change is 30 sec.
In general, OFAN starts together with COMP.
12.4.4 HE
operation
Minimum Heaters ON or OFF time is 30 sec.
Heaters can be activated only if IFAN is on.
CONTENTS
