Description
Features
- Small construction
- Varying temperature ranges can be combined in one enclosure
- Can be mounted directly in Zone 1
- Temperature can be set in Zone 1
- Many variants available
Description
The STW II is a compact ON/OFF type capillary tube thermostat, housed in an Ex e certified polyester enclosure. Heaters, fans, motors and other equipment are energised and de-energised by means of this thermostat when specific temperature ranges are exceeded. This device can also be used to control the temperature in air or on various surfaces.
Function
Any change in temperature at the sensor bulb causes a change in the volume of fluid in the measuring system, which in turn results in a movement of the diaphragm membrane. This membrane is connected to a mechanical device that activates a microswitch. If the temperature at the sensor bulb exceeds the pre-set value, terminals 1 and 4 are opened. If there is a rupture or break in the sensor tube (leakage), then the switch remains permanently open (fail-safe). If the temperature falls below the minimum setting, the autocontrol opens the circuit but closes again on temperature rise.
Technical data *
Protection class: IP 65 (EN 60592)
Dimensions:
Device for 1 heating circuit: 120 x 122 x 90 mm (L x W x H)
Device for 2 heating circuits: 220 x 120 x 90 mm (L x W x H)
Capillary tube: up to 5000 mm
OD sensor line: 1.5 mm
min. bend radius: 5 mm
sensor bulb diameter: 4 to 6 mm
Material:
Enclosure: polyester
sensor material: stainless steel S/S 1.4571
Weight: approx. 400 g
Temperature range: -20 °C to +300 °C (mechanical)
Current:
Switching current at 230 V
open contact: 16 A (AC-1)
closed contact: 2.5 A (AC-1)
Connection
Device for 1 heating circuit
Terminals: 4 x 2.5 mm² + 1 PE
Heating cable connections: 2 x M25
Device for 2 heating circuits
Terminals: 6 x 2.5 mm² + 2 PE
Heating cable connections: 2 x M25