Electra PXD912 Service Manual page 74

CONTROL SYSTEM
11.3.7 RV Fault
This test is applied only in compressor units where 4.7k: resistor is not connected to
the OCT.
The test is performed every time the unit is switched from OFF/STBY to OPER in Heat
mode or changes operation mode from COOL/DRY to HEAT or (this applies also in
AUTO COOL/HEAT mode).
If ICT is lower than 35
min continuous COMP operation, ICT is compared with ICT reading when the COMP
was switched from OFF to ON 15 min before. RV fault is defined when ICT decreases
more than 5
In this case, the COMP will stop and the SB LED will blink. The fault is reset after
switching to SB or after mode change.
11.3.8 General Features
a. Allowed (control target) range for RAT is SPT +/-1ºC.
b. Whenever the unit is changed from COOL/DRY/STBY mode to HEAT mode or
vice versa, the procedures below are followed:
Stop COMP for 3 min o Change RV state o Start COMP if necessary.
11-8
º
C at the time of mode change, then at the first occurrence of 15
º
C.
CONTENT
SM PXD 1-E.3 GB