Mitsubishi Electric LGH-50RSDC-E1 Handbook page 11

Cold region operation mode
When using the unit in cold region, set the air supply (SA) fan in the SA intermittent operation mode to pre-
vent the Lossnay core from freezing. The fan operation is based on the measured outside air (OA) tempera-
ture as below.
Operation mode
Normal -10°C < OA temperature
SA intermittent -15°C < OA temperature
SA stopped
OA temperature -15°C
1 The operation mode will be decided 5 minutes after the normal operation during startup.
2 The running condition does not change while the SA fan stops or 1 minute after startup. (OA temperature
is voided.)
3 When the switch SW 1-3 is on, the EA fan operates at fan speed 5 during 55-minute stop of the SA fan.
(2) Damper motor control
Automatic ventilation mode
Automatic ventilation algorithm patterns are switched by the OA • RA (return air) thermistor and function set-
ting switch SW 1-6.
Function setting switch SW1-6
OFF (factory setting)
ON
Power bypass mode
When the TM3 PB contact is turned on with any fan speed contacts (1 to 5) on, operation mode will be
switched to bypass ventilation. Then, fan speed will be also increased to Power bypass speed.
Ventilation priority mode
When the TM3 V contact is turned on with any fan speed contacts (1 to 5) on, operation mode (energy re-
covery or bypass) can be fi xed by the function setting switch SW 1-4. (Fan speed will not be changed in the
bypass ventilation mode.)
Function setting switch SW1-4
OFF (factory setting)
ON
Prohibition of the bypass ventilation
In the case of the situations below, bypass ventilation will be disabled, and energy recovery ventilation set-
ting will be activated.
a. OA temperature
b. OA • RA thermistor failure.
OA temperature
-10°C Repeat 10 min. stop / 60 min. running
OA temperature criteria
in the summer season
17°C or higher
28°C or higher
Bypass ventilation fi xed
Energy recovery ventilation fi xed
8°C (for dew condensation prevention)
SA fan
Continuous running
1 2
1 2
Repeat 55 min. stop / 5 min. running
1 2
Automatic ventilation pattern 1 (chart 1)
Automatic ventilation pattern 2 (chart 2)
Ventilation priority mode
─ 11 ─
Continuous running
Continuous running
Continuous running
3
Automatic ventilation algorithm
EA fan