DTL III Ex Digital Safety Temperature Limiter



  • ATEX approval
  • Optimised for trace heating applications (with service entry)
  • Sensor surveillance
  • In conjunction with Pt100 Ex, it can be used for monitoring temperature in explosion-proof heating circuits


Ex II (2)GD [Ex e GB]

Ambient temperature

0 °C to +50 °C


TÜV 08 ATEX 554871
TC RU C-DE.GB06.B.00399


The digital temperature limiter DTL III Ex is designed for trace heating applications and is used for temperature monitoring of heating systems or heating circuits. The device is installed in the non-hazardous area. The heating or heating circuits can be installed both in media-protected and also in hazardous areas. Thanks to their integrated power supply unit with wide-range voltage, the devices can be used almost everywhere in the world.


If the temperature at the Pt100 exceeds the set limit value, the DTL III Ex permanently interrupts the normally open 16 A switch contact. This situation is detected by a volt-free alarm contact (change-over contact) and passes on the signal to the control panel. After a temperature drop of 5 K below the limit set point, or after a fault has been remedied, the limiter can be re-activated by means of a re-set button on the device itself or via a remote re-set control. The DTL will also interrupt the switch contact in the event of a sensor open or short circuit. Process reliability is increased by additional monitoring functions such as pre-alarm, measuring circuit monitoring for sensor break, interruption and short-circuit as well as undershooting/overshooting of the measuring range. A multi-stage password management is available for effective parameter protection. When doing service work on the heating circuit, the load output can be turned off by means of a digital input and the temperature alarms can be disabled. Through the programming interface, the device parameters can be transferred to other devices by using a special programming key.

Technical data *

Protection class II
Dimensions 84 mm x 70 mm x 60 mm (Length x Width x Depth)
Weight 0.2 kg
Operating temprature range 0 °C to +50 °C
Measurement range -200 °C to +850 °C
Sensitivity (± 0.5% of the actual level or ±1°C;the higher level applies)±1 digit
Voltage see data sheet
Current see data sheet
Power Max. 4 VA
Electrical life relay outputs: at least 100,000 switching cycles

*Refer to the documentation for more detailed information


Data Sheet - DTL III Ex Digital Safety Temperature Limiter

EU Declaration of Conformity 11-8865-7C0001_A

Operating Instructions - 288307_DTL II