Thermostats TH 220, TH 221


Thermostat consists of a stem and a switch head. Temperature-sensitive element is formed by brass tube of the stem. Temperature-depending dilatation of the tube is transferred by invar rod to switch mechanism. The switch mechanism is snap-action single-pole switch. Switch mechanism is closed in thermostat head. Temperature scale is marked directly on the regulation knob.
The thermostat can be mounted with screws using two holes at its base plate. Avoid mechanical stress of stem during installation. When used in vibrating equipment, attach the free end of the stem (but do not restrict the dilatation) and fix the set temperature by tightening of the locking screw. Contact are bridged by capacitors for switching of the DC current.


  • high sensitivity
  • resistance to humid and dusty environment  

Technical data

Control range -20 °C to +60 °C
Switching difference 1-3 K
Setting accuracy ±5 % from the highest rated switching temperature
Rated voltage, rated current 60V1A DC; 120V, 0,5 A DC (TH 220)
250V15A AC (TH 221)
Stem length 560 mm
Weight approx. 0,8 kg
Protection IP 44
Resistance to external influences head resistant to influences of class AB7AE3AM1AN1BE1
Max. temperature of the switch head 120 °C
Max. temperature of the stem 140 °C
Lifetime 10 000 cycles

Dimensional drawings

Files to download

Catalogue sheet

Photos of the product

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