OM-TDB/TDBC-CE 11
Sequence of Operation
The following “action-reaction” outline is provided to help understand how the kettle
works.
When the operator starts up the kettle by turning on the power switch and the
operating the thermostat dial from “O” to a desired setting, the thermostat switch
closes. This lights up the HEAT indicator light and causes the contactors to close,
allowing power to flow to the heating elements. When the temperature of the steam
jacket reaches the value corresponding to the dial setting, the thermostat switch
opens. This turns off the HEAT indicator light and causes the contactors to open,
stopping the power to the heaters. As soon as the thermostat senses that the kettle
is cooling below the set point, the thermostat switch closes, the HEAT indicator
light comes on, the contactors close, and the heaters come on again. On-off cycling
continues, keeping the kettle at the set temperature. This is why the heating indicator
light cycles on and off during normal operation. Every time the kettle is tilted, a tilt cut-
off switch interrupts the power supply to the heaters, so that the heating elements will
not operate while not submerged in the jacket water.
If steam pressure greater than 50 PSI (3.45 Bar/345 kPa) is generated in the jacket,
the pressure relief valve will open and relieve the excess pressure.
If the jacket water level gets too low and the heating elements overheat, the high-limit
control will open, shutting off power to the elements until the kettle cools.
Setting the operating thermostat dial to “O” shuts down the heating circuits. Setting
the power switch to the OFF position removes power from the control circuits.
