General Functions; Comp Operation; Ifan Operation; Ofan Operation - Electra WNG 7 Service Manual

CONTROL SYSTEM
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
Fan, Dry, Overflow, Protection modes, or mode change
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:
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:
IFAN speed
H
M
L
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.
12-4
Operation Mode
Heat, Cool or Auto Modes
∆T
∆T ≥ 2
2 ≥ ∆T ≥ 1
1 ≥ ∆T
1
Revision Y05-03
CONTENT
Min operation time of
IFAN Speed
HIGH
MED
LOW
2 3 T [
COMP
3 min.
ignored
o
c]
Service Manual - WNG