Despatch 926E Equipment Manual (C-155)Rev 2/11 - Manual (Page 47)

42
HI-LIMIT Thermoswitch
Adjust and test the factory calibrated HI-LIMIT thermoswitch as follows.
1.
The thermoswitch was factory set and tested at the chamber maximum rated
temperature within normal tolerance.
2.
If necessary to reset the thermoswitch. It is accessible by removing the snap in
closure button in the rear cover panel.
3.
A screwdriver can be inserted through the hole to find the end of the slotted
adjusting screw.
4.
Turn screw clockwise to reduce temperature. Adjusting rate is approximately 90

F per revolution.
5.
To set a new temperature on the thermoswitch.
a. Set the chamber control to the desired trip temperature and allow
temperature to stabilize.
b. The panel mounted over-temperature set point must be set at a higher
temperature for this test.
c. Slowly turn adjusting screw clockwise until the thermoswitch trips and the
chamber is shut down.
6.
Test the set point.
a. Allow the chamber to cool.
b. Open and close the power switch to reset.
c. Set the chamber controller above the set point.
d. Observe the temperature at the time it is tripped.
The chamber with thermoswitch UE8625 will be reset automatically when the
temperature drops below the over- temperature set point.
7.
Reset the electronic over-temperature set point to the desired temperature.