Electronic thermostats


High temperature alarm with 2 adjustable alarm temperatures. Multi-voltage: 24V AC/DC and 230V AC

Contact us
  • Need help? Contact us between 8 am – 4 pm every weekday (CET)
  • 5-year product warranty
  • Product noteWe arrange shipment to almost every country
  • Product information
  • Documents
Product information

Description CTA-24/230V

CTA is an overheating alarm for use in fire monitoring, industrial applications, etc.

CTA can be supplied with 24V AC/DC via terminal 15-16 or 230V AC via terminal 1-2. CTA has two alternating potential-free relay outputs (5A, 250V).

During start-up and when replacing a temperature sensor CTA conducts a self-test. 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 alarm reference values for relay 1 are shown in the upper left-hand corner and for relay 2 in the upper right-hand corner of the display. The “greater than” symbol (>), to the left of the alarm reference values, indicates that the relays enter into an alarm condition when the temperature is higher than the alarm temperatures.

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

It is possible to set an alarm delay time (0-120 minutes, factory setting: 0 minutes).

CTA monitors the temperature sensor and deactivates the relays (enters alarm condition) in the event of a short-circuit or interruption in the sensor circuit. In the case of interruption the thermometer sensor shows Er0 and in the case of short-circuit Er1 is displayed.


CTA is designed for mounting on a DIN rail and is adapted for Norm enclosures.


  • Multi-voltage 24V AC/DC and 230V AC.
  • Very easy configuration
  • Backwards-compatible with Calectro’s high temperture alarms
  • 2 alternating potential-free relays
  • Display
  • Built-in timer function
  • Fine-adjustment of the temperature measurement

Documentation, software and images

Related products


Temperature sensor for ventilation ducts, with housing. Variable...


Temperature sensor for ventilation ducts, with cable. Variable...


Outdoor temperature sensor with spacer bracket, Pt1000. Temperature...


Temperature sensor for room, Colour: white. Pt1000. Temperature...


Bulb temperature sensor 50 mm. With 1,5m cable....


Strap-on temperature sensor 50 mm. With cable, Pt1000....


Immersion temperature sensor for fluids, with housing. Pt1000....


Immersion temperature sensor for fluids, with cable. Pt1000....

View all our products