Calectro CMT-24/230V

CMT-24/230V

CMT is a universal thermostat with 11 built-in and selectable functions:
Appl. 1 1-stage heating thermostat
Appl. 2 1-stage cooling thermostat
Appl. 3 2-stage heating thermostat
Appl. 4 2-stage cooling thermostat
Appl. 5 2-stage heating and cooling thermostat
Appl. 6 1-stage cooling thermostat with low temperature alarm
Appl. 7 1-stage heating thermostat with overheating alarm
Appl. 8 2-stage high temperature alarm
Appl. 9 High and low temperature alarm
Appl. 10 Gutter thermostat
Appl. 11 Gutter thermostat with whole numbers, relay 2 = fault alarm

CMT can be powered by 24V AC/DC via terminal 15-16 or 230V AC via terminal 1-2. CMT has two alternating potential-free relay outputs (5A, 250V) and has an adjustable hysteresis (switching differential) which is centred over the set point.

CMT carries out a self-test during start-up and following change of temperature sensor. Three bars blink at the lower part of the display. Once the self-test has finished the actual temperature will be displayed. In the case of temperature sensor interruption the code Er0 is displayed and in the case of short-circuit Er1 is displayed.

The set point for relay 1 is shown in the upper left-hand corner, and for relay 2 in the upper right-hand corner of the display. The ‘less-than’ symbol (<), to the left of the set point, indicates that the relay is calling for heat (or starts an alarm) when the temperature is lower than the set point. The ‘greater-than’ symbol (>) indicates that the relay is calling for cooling (or starts an alarm) when the temperature is higher than the set point.

CMT has an adjustable hysteresis (switching differential) which is centred over the set point. The factory setting for the heating thermostat is 0.6°C and for the cooling thermostat 1.0°C. No hysteresis is used in alarm functions.

If necessary the temperature measurement in the CMT can be adjusted. Range: -3.0°C to +3.0°C in steps of 0.1°C.

In the alarm applications (applications 6-9) it is possible to set a delayed alarm period (0-120 minutes). for example to be able to defrost without activating the alarm. In the application for the gutter thermostat (application 10) an after-running time can be set (0-120 minutes) to ensure de-icing.

CMT has a monitor for the temperature sensor and disconnects from heating or cooling in the event of short-circuit or interruption in the sensor circuit. In the alarm applications (applications 6-9) the relays are deactivated (enters alarm condition) in the event of sensor failure. In application 10 (gutter thermostat) the relays call for heating in the event of sensor failure, to counteract the formation of icicles.
Installation
CMT is mounted on a DIN rail and is adapted to Norm enclosures.

Properties