Techne RS232 - Manual (Page 20)

D B - 3 D w i t h R S 2 3 2 O P E R A T O R ’ S M A N U A L
P A G E 18
Setting the Overtemperature Cut-out
DB-3D
An adjustable overtemperature cut-out is fitted to these units. As supplied it is
set to remove power from the heater should the block temperature exceed
approximately 210°C. If you need to prevent the block temperature exceeding
a lower value, the overtemperature cut-out may be re-adjusted downwards.
Note that the cut-out should be set to trip at least 5°C above the maximum
desired operating temperature.
To set the overtemperature cut-out, turn the reset button (located on the back
panel of the unit) fully clockwise then:
either:
• Heat the block to the desired cut-out temperature and turn the reset button
anti-clockwise until the unit just cuts out.
or:
• Heat the block to the required maximum operating temperature and turn the
reset button anti-clockwise until the unit just cuts out. Now turn the reset
button an additional small amount clockwise.
When the cut-out operates, the unit stops working and the overtemperature cut-
out indicator lights.
Remove the block from the unit by screwing the extractor tool into the
thermometer hole and lifting the block vertically. Remember that high
temperatures are dangerous; wear insulating gloves and take extreme care. Wait
for the temperature to fall, perhaps by as much as 40°C, and press the reset
button. The unit will now work as usual.