4.2.6 Thermostat
Thermostat type
Two types of thermostat can be utilized for temperature control.
Electronic thermostat (NTC sensor)
The electronic thermostat provides active temperature control.
Disconnected sensor error alarm (NTC sensor failure) is sent when the measured temperature is
›+100ºC
Short circuited sensor error alarm (NTC sensor failure) is sent when the measured temperature
‹-50ºC
Mechanical thermostat
A mechanical ON/OFF thermostat can be connected at terminals C & T.
No detection of faulty thermostat is provided when an ON/OFF thermostat is used.
Automatic thermostat selection
The Thermostat parameter displays the type of thermostat connected to the controller: either a
mechanical thermostat or NTC temperature sensor.
An NTC sensor is recommended for the temperature range -50 ºC to +100 ºC
A mechanical thermostat is recommended for temperatures below -50 ºC and above +100 ºC
Note: An NTC sensor error is not detectable when the NTC sensor is operating in automatic
thermostat selection mode.
An over temperature alarm (NTC sensor failure) is raised if the measured temperature
exceeds+100ºC
An under temperature alarm (NTC sensor failure) is raised if the measured temperature drops
below - 10ºC
Settings:
Name Default Max value Min value Step Unit
Thermostat type Auto Electronic - - -
Cutout temperature + 25 + 40 -40 1 Celsius (°C)
Difference 3 15 1 1 Kelvin (K)
Forced ON OFF ON OFF 1 -
Cutout temperature 2 25 40 -40 0.1 ˚C
Difference 2 3 15 1 0.1 K
Forced ON 2 0 1 0 1
0 = OFF
1 = ON
Synchronic mode 1 1 0 1
0 = OFF
1 = ON
Measurements:
Name Description Step Unit
Runtime Runtime is provided to record cooling-time (thermo-
stat cut-in period). The runtime is updated during coo-
ling, starting with 0 at start of cooling.
During cooling OFF (Thermostat cut-out), the Runtime
parameter will show the time for the last cooling peri-
od. Runtime is reset at the beginning of a cooling ON
period, and at power-up.
1 Minutes
Actual temperature Real-time air temperature when a NTC sensor is used.
When a mechanical thermostat is used, only thermo-
stat status ON or OFF is displayed.
- °C