Type UWJ: Temperature limiter for explosive gas atmospheres


Motor thermal protection, heat tracing, alarm and high temperature safety in explosive gas atmospheres.

Main features

Classification: Ex mb IIC (Testing certificates: ATEX INERIS 15ATEX0018X and IECEx INE15.0022X).

Ambient temperature limits on enclosure : -40 to +150°C

Comply with the following standards:

– EN 60079-0: 2012/A11:2013

– IEC60079-0: 2011

– EN 60079-18: 2009

– IEC 60079-18: 2009

– EN 60079-31: 2014

– IEC 60079-31: 2013

Operating principle: bimetal disc crossed by the current, and whose shape change activates an electrical snap action contact.

Enclosure: Zamac, 31mm x 19mm x10mm. Ingress protection class IP65.

Mounting: by 2 holes dia.3mm

Set point: fixed factory set minimum 50°C maximum 150°C. (Calibration values ​​are always zero current values).

Calibration tolerance: ± 5 ° C on the opening temperature (± 3 ° C on request)

Differential: fixed, not adjustable by the user. About 40°C at zero current.

Electrical rating: 9A 240VAC resistive, 3A, 240VAC inductive, 10,000 cycles. (13A resistive version is possible, consult us)

Current Sensitivity*: These devices are sensitive to the electrical intensity, and the cut-off temperature will be less than the nominal calibration temperature according to the table below:

Rating 3A 5A 7A 10A
Offset -2.5° C -5°C -10°C -20°C

Connection: by silicone insulated cable, 2 x 1 mm², O.D. 6.3mm. Withstands temperatures from -60 to + 180 ° C. The cable shall be protected, during installation, against shocks and risks of mechanical destruction. The cable must be fixed so that there is no risk of tearing it off the thermostat. The electrical connection must be made according to the specifications of the zone (EN 60079-0). In function of the ambient temperature on the cable, the intensity must be less than the values ​​below:

Maximum ambient temperature on the cable:

Temperature 120°C 140°C 170°C
Intensity 12A 9A 5.4A

Cable length: Can be cut on demand. Standard lengths: 1m, 3m, 5m

Short circuit trigging*: If an overcurrent occurs in the circuit, the thermostat contact will switch off automatically. The table below gives the response time in seconds of the thermostat according to its set point calibration and overcurrent. Measurements made at an ambient temperature of 20°C.

Temperature calibration

Trigger time

15A 20A 25A 30A 35A 40A
90 100s 30s 11s 5s 2.5s 1s
110 150s 40s 20s 8s 4s 2.5s
130 250s 80s 30s 12s 6.5s 4s
150 400s 150s 45s 18s 9s 6s

*Indicative values, they ​​may vary depending on the installation characteristics. If these values ​​are critical in the application, we recommend performing validation tests.

Main references

Cable length

Calibration temperature (±5°C)


110°C 130°C


1m UWJZKP100905B00A UWJZKP101105B00A UWJZKP101305B00A UWJZKP101405B00A
3m UWJZKP300905B00A UWJZKP301105B00A UWJZKP301305B00A UWJZKP301405B00A
6m UWJZKP600905B00A UWJZKP601105B00A UWJZKP601305B00A UWJZKP601405B00A



2D&3D Drawing