2 Basic Operating Instructions
2.1 Furnace or Oven Controls
Most Carbolite Gero products are fitted with an “Instrument Switch” which cuts off power to
the controller and other parts of the control circuit. See the instruction manual for the
furnace or oven for the overall operating instructions.
To operate the 3216OT there must be power to the furnace or oven, and the Instrument
switch must be on. If a time switch is included in the furnace or oven circuit, this must be in
an On period.
When an over-temperature condition occurs, the controller cuts the power to a contactor,
which in turn cuts power to the heating elements. Power is not restored until the controller is
“reset”. Other components do not generally have power to them cut on over-temperature;
oven fans usually remain running, but may not do so if other options (such as a door switch)
are fitted.
2.2 The 3216OT Operation - Set Point Tracking
When switched on, the controller lights up, goes through a short test routine, and then
displays the measured temperature and the over-temperature set point.
The 3216OT set point tracking is connected internally to the main temperature controller.
The main controller transmits its set point value to the over temperature controller. A local
deviation high alarm of 15C is added to the retransmitted set point. The over temperature
controller thus automatically tracks the main set point and does not require adjustment
when changing the main temperature controller set point.
If the oven is hot and the set point of the main controller is turned down more than 15C
then the over temperature circuit will trip.
The Scroll key allows access to the parameters within a list. Some parameters are
display-only; others may be altered by the operator.
A single press of the scroll key in the Home list displays the ID.
To return to the Home list at any time, press Page and Scroll together, or wait for 45
seconds.
The Down and Up keys are used to alter parameter values.
2.3 Basic Operation - Set Point Tracking
No adjustment of the over temperature controller is necessary in normal use. The unit is
supplied with the tracking over temperature value set to track at 15°C above the furnace or
oven set point temperature.
