Product Finder
... Products

Thermal Protector CRH

Power class: 13,5 A to 42,0 A
Type series: RH

  • normally closed
  • does not reset automatically
  • with connector cables
  • without insulation
Download datasheet
Thermal Protector CRH
Thermal Protector CRH
Thermal Protector CRH
Thermal Protector CRH

Switchgear consisting of a mobile and circumferential contact bridge (1), a contact bearing pin (2), a spring snap-in disc (3) and a bimetallic disc (4) which is riveted into one another, undetachable and fixed in a positive lock and self-aligning between a non-conductive floor of a housing (5) and an insulating ceramic bearing (6) with two integrated stationary contacts (7). At the same time, the switchgear is supported by the spring snap-in disc (3) with the contact bridge (1) acting as a transfer element for electric current which is held between a supporting collar and a circumferential ring. As such, the bimetallic disc (4) underlying it, that is also stuck out from the contact bearing pin (2), can continuously work (exposed) by mechanical loads without the contact pressure defined by the spring snap-in disc (3) diminishing. As soon as the bimetallic disc (4) reaches its rated switching temperature, it effectively springs against the throw force of the spring snap-in disc (3) into its inverted position. The contacts (7) are abruptly opened. The resistance ceramic (6) switched in parallel now sustains the operating voltage and deploys a defined electrical heating output on the switchgear regardless of the ambient temperature and permanently sustains it above its springback temperature so that the switchgear cannot reset back. The contacts (7) remain open. The Thermal protectors can only cool down again and switch to the original closed state when the external operating voltage is no longer applied and/or disconnection from the mains.

Technical specifications

Nominal switching temperature (NST) in 5°C
70 °C - 180 °C
Tolerance NST ≤ 140 °C
±5 K
Tolerance NST > 140 °C
±10 K
Reverse switch temperature (RST)
≥ 35 °C
≥ 35 °C
(defined reset temperature possible on customer request)
Installation height from
6.5 mm
9.0 mm
Resistance to impregnation
Suitable for installation in protection class
Pressure resistance to the switch housing
600 N
Standard connection
Lead wire 1.0 mm² / AWG18
Operating voltage range AC
up until 250 V AC
Rated voltage AC
120 V / 230 V (VDE) 250V (UL)
Rated current AC cos ϕ = 1.0 / cycles
13.5 A / 300
Rated current AC cos ϕ = 0.6 / cycles
9.0 A / 300
Max. switching current AC cos ϕ = 1.0 / cycles
42.0 A / 300
Total bounce time
< 1 ms
Contact resistance (according to MIL-STD. R5757)
≤ 50 mΩ
Vibration resistance at 10 ... 60 Hz
100 m/s²


Icon Close
+49 (0) 3632 5412-110
+49 3632 5412-0
Go to top To the top