8-6
CONTROL SYSTEM
Revision Y05-01
Service Manual - DNC Series
2. General
functions
for
all
models
2.1. COMP
operation
2.1.1. For each Mode including POWER OFF & SB, a Min time delay of 3 min
before COMP restarting, excluding DEICING Mode (see 7.2.1).
2.1.2. 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
2.2. IFAN
operation
2.2.1 Whenever the IFAN starts from OFF to ON it will start in Low speed
for 25 sec and then will go to ANY speed.
2.2.2 Min time interval between IFAN speed change in AUTOFAN Mode, is
30 sec.
2.2.3 Min time interval between IFAN speed change in H/M/L Mode is 1 sec.
2.2.4 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:
1. In Heat Mode, the rules in section 4.0.3 have the higher
priority.
2. 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
2.4. OFAN
operation
2.4.1 Min time interval between OFAN ON/OFF state change is 30 sec.