11-14
CONTROL SYSTEM
SM TQDCI 1-A.1 GB
11.5.4
Outdoor Fan Speed Control
11.5.4.1 General
Rules
o
OFAN operates between
OFMinRPM
to
OFMaxRPM
.
o
o
The OFAN speed is consecutive and related to the high pressure of the system.
The fan speed is also related to compressor speed, outdoor temperature and to protections.
11.5.4.2 Behavior when there is a failure in OFAN
Whenever OFAN fault occurs the compressor will be stopped immediately, except during
deicing protection, then the OFAN will be enabled to be started for maximum 5 times. This rule
is enabled each time the ODU switches to heat/cool modes.
11.5.4.3 Protection
Behavior
•
When in total IDU protection level is different than normal, the OFAN will reduce
OFSpdReducePrtC
and
OFSpdReducePrtH
RPM for cool and heat respectively
.
•
In cool mode the OFAN will operate according to CTT or HST protection level:
Protection level
Action
SR, D1
or
D2
OFAN will add 100 RPM to the target speed
Stop-Compressor
continue to operate for maximum 2 minutes at it last speed or until normal level is
achieved.
11.5.4.4 OFAN Force On condition
If HST is higher than 70°C or defined as “HST bad”, OFAN will remain ON at the last operating
speed for maximum 2 minutes after COMP is OFF.
11.5.4.5 Night
mode
Upon receiving night mode, the OFAN will be limited to max
NightRPM
speed only in Cool. It
will be back to its normal operation when receiving the mode is cleared.
11.5.5 RV
State
Setting
During heat mode (except during Deicing) RV is ON.
During cool/SB mode RV is OFF.
RV status will be changed only if COMP is OFF for 3 minutes or more.
11.5.6
Base Heater Setting
The base heater will be working only when RV is “ON” according to the following graph:
CONTENTS
