Electra PXD912 Service Manual page 79

c. IFAN operation rules for RH group
1) In RH group, IFAN starts when HE starts. When HE switches to OFF, IFAN
switches to LOW for 30 sec and then stops.
d. Heaters operation rules for RC and SH groups:
1) For both RC and SH groups, Heaters versus T is as follows:
ON
OFF
ON
OFF
1
2) Operation rules for Heaters in RC group:
a) Heaters can be enabled only if IFAN is ON.
b) Heaters will operate according to T and the following graph:
HE-1
&
HE- 2
ON
OFF
General:
Window:
3) Rules for Heaters operation in SH group:
a) When heaters are to be ON and IFAN is to be OFF according to d. 1)
above, IFAN will be forced to LOW speed.
b) Heaters will operate according to T and the following graph:
ON
HE -1
OFF
ON
HE - 2
OFF
37
4) For both RC and SH groups, excluding deicing, HE1 and HE2 can be ON only
when the compressor is ON.
SM PXD 1-E.3 GB
HE1
HE2
2 3
20 32
15 20
42 45 50
CONTENT
o
T=SP-RT [ c]
4
ICT
45 50
ICT
CONTROL SYSTEM
11-13