Types SR and SU: SPDT Bimetal rod thermostats



Applications: water and liquid temperature control, circulation heaters, hydraulic circuits oil temperature etc…

Temperature ranges: : 0-50°C (32-122°F), 10-60 °C (50-140°F), 30-90°C (86-194°F), 0-100°C (32-212°F), 40-140°C (104-284°F), 0-150°C (32-302°F)

Housing dimensions: 65 x48 x 48 mm (knob not included).

Material: PA66 housing, and Aisi 304 stainless steel rod.

Temperature sensing element:  Invar/stainless steel bimetal rod, temperature sensing on  full rod length.

Electrical connections: screw terminals.


– For liquid temperature sensing: inside pocket with internal diameter > 10 mm , or directly on 3/8”BSPP thread under the head, or with 3/8 x1/2” fitting (see accessories)

– For air  temperature sensing measurement: with stainless steel bracket

Rating: 16(4)A 250/400VAC, 300.000 cycles. Reduced differential model is not recommended for 400V applications.

Contacts: SPDT, snap action

Max ambient temperature on the head: 85°C  (185°F)


-3 fixed setting staggered contacts for  hydraulic power units : ask for specific data sheet

-Cnomo electrical connector

Other temperature ranges.

-IP65 aluminum housing: See catalogue N°2

Accessories: BSPT1/2 stainless steel pocket, fittings, brackets , see description and references at the end of this catalogue

Approvals: comply with EN 60730-1 and EN 60730-2 standards


Main references

Temperature range

°C (°F)

Rod length  (mm) Reference with standard differential* Differential value

°C (°F)

Reference with reduced differential* Differential value

°C (°F)

Max. temperature on rod

°C (°F) 




450 SRA0000500045C 3±1.5°C (5.4±2.7°F) SUA0000500045C 1.5±1°C (2.7±1.8°F) 70°C (158°F)
10-60 °C


450 SRA0100600045C 3±1.5°C (5.4±2.7°F) SUA0100600045C 1.5±1°C (2.7±1.8°F) 80°C (176°F)


380 SRA0300900038C 4±2°C (7.2±3.6°F) SUA0300900038C 2±1°C (3.6±1.8°F) 110°C (230°F)


230 SRA0001000023C 6±3°C (10.8±5.4°F) SUA0001000023C 3±1.5°C (5.4±2.7°F) 130°C (266°F)


230 SRA0401400023C 6±3°C (10.8±5.4°F) SUA0401400023C 3±1.5°C (5.4±2.7°F) 170°C (338°F)


170 SRA0001500017C 8±4°C (14.4±7.2°F) SUA0001500017C 4±2°C (7.2±3.6°F) 180°C (356°F)

* These products can also be supplied with Cnomo connector electrical output: Replace the last number in the reference “0” by “1”



2D&3D Drawing