WIKA A2G-65 User Manual

Page 10

WIKA operating instructions air2guide model A2G-65

40338355.02 05/2012 GB/D/F/E/I

6. Commissioning, operation

1 - 2 Normal operation

1 - 4 Risk of frost

Connection diagram

The switch in the frost protection thermostat trips when the tempera-

ture over a capillary length of at least 60 cm drops below the selected

set point (contact 1-4 makes). Simultaneously, contact 1-2 breaks

and can be used as a signal contact. An automatic reset (contact 1-2

makes) occurs when the temperature once again exceeds the selected

set point. The air2guide AFT is “intrinsically safe”, i.e. in the event of

any damage to the capillary tube diaphragm system, it automatically

switches to the heating function. Contact 1-4 makes and can thus be

used as an operating contact. The air temperature is measured over the

full length of the sensor (capillary tube).

Commissioning

It is recommended to mount the frost protection thermostat on a special

plate (slide-in module), directly downstream of the heating coil. The

connecting cable must therefore be long enough to enable the plate to

be inserted and removed smoothly. For heating coils with a very large

cross section, several frost protection thermostats can be fitted and

connected in series. In such cases, the temperature set point is set

individually for each frost protection thermostat.