WORKING OF THE GAS FIRED ROTISSERIE
Page 38
Service Manual TDR8 P Gas form 9124023 rev. 01/2022
After plugging the unit in always first check the proper polarity for good ignition.
After starting the rotisserie up with the on/off key the reset will light up. First press this switch for 2
seconds till the light is out. Also the gas mixture blower will turn in very low speed for max. 9 min-
utes in stand by position regulated by the burner control. The continuous power on the gas mixture
blower is activated by contact X13 on the Power and I/O board which activates relay K2.
After selection of a program and pressing the OK key the PT 1000 temperature sensor measures a
temperature below the set temperature and this will activate relay K1 by contact X9 on the Power
and I/O board. Relay K1 activates the burner control sequence. This sequence is as follows:
- Activating of low speed of the gas mixture blower to create a rich gas/air mixture for easy and fast
ignition.
- Activating of spark plug (max. 5 seconds).
- Activating/opening of the gas valve.
- Activating of the ionisation (measuring of a low Amperage (~35mA) between ionisation pin and
burner bed).
- Activating the high speed of the gas mixture blower when the gas is burning and the ionisation
measuring is OK.
Note:
If the speed of the gas mixture blower is not within 5% of the adjusted speed in the burner
control there will be no ignition and the red indication light on the reset switch will light up. In this
case the blower has to be replaced.
The PT 1000 temperature sensor now takes care of the temperature regulation of the oven, by
switching the burner control on and off.
If there is no ignition/burning of the gas/air mixture after 5 seconds of ignition there will be a pause
of 5 seconds and after this the ignition sequence will start up for maximum 2 times. If there is still
no burning of the gas the burner control will close the gas valve and activates the red indication
lamp on the reset switch. By pressing the rest switch for 2 seconds the sequence will start up again.
After ending of a grilling process the gas mixture blower will keep on turning for 9 minutes on
an adjusted speed, regulated by the burner control to ensure that there is no gas left in the heat
exchanger and is clean. After this 9 minutes the gas mixture blower will turn continuous in very low
speed.
The continuous power on the gas mixture blower is activated by contact X13 on the Power and I/O
board which activates relay K2.
After intermediate stopping (door open) of the program or when the program is stopped the gas
mixture blower will run also for 9 minutes.
Note: Gas supply pressure should be between 15 and 50 mbar, depending on the gas type. See table
on next page.
Pressure over 60 mbar will damage the gas block. You can check the pressure on the gas block, see
page 42. Valves on the gas block can be checked by holding your hand on it, or by holding a steel
object on the coil. This will be magnetic after switching in.
WORKING OF THE GAS FIRED ROTISSERIE
