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STDITR01ADP2090EV TECNOFRIGO TUSCANY srl
Burner safety control unit.
The control unit ensures safe ignition, start-up and shutdown both during normal operation and in the
event of a fault. This is equipped with a self-diagnostic flux monitoring circuit that controls the
combustion process. The flame monitoring circuit applies the necessary safety measures if the flame
signal is activated too early or not activated at all, and if any type of fault occurs in the flame detector,
in the detector cables or in the signal flame.
Faults that are detected during the start-up procedure or normal operation cause the shutdown.
Operation is therefore prevented until the fault is cleared and the burner control unit is reset by resetting
the alarm.
When the relay is powered and the start contact is closed, the burner control unit moves to the "start"
position. When the burner control unit receives a start signal from the PLC, an automatic check is
performed between the burner control unit and the regenerative airflow pressure switch. This is to
ensure that a flow of air is present in the combustion chamber before starting the flame.
If after contacting the fan, the pressure switch contact does not close (in the "no air" position), the
control unit will not start.
Immediately after the regeneration air fan is started, the burner control unit checks whether the
pressure switch contact closes (the supply of combustion air is available).
If the contact has not closed, the control unit stops the burner start-up.
When the flow switch contact is closed, the discharge period begins. For about 30 seconds, all remaining
gases are purged from the combustion chamber. Once the exhaust period is over, the ignition is switched
on. After a few seconds the gas supply valves (V1 and V2) receive the power supply. If a flame has been
lit and the flame has been detected by the probe, the relay will continue to operate until it reaches its
ignition position. If no flame is present or it is not detected, the relay generates a burner lock, closing
(V1 and V2) immediately. The program light stops at the position where the problem occurred as an aid
in troubleshooting.
Schedule light.
The program light shows the status of the burner. Since the program light remains in the position where
the shutdown occurs, this provides useful information that facilitates troubleshooting. The various
situations that cause stopping are indicated by the following symbols:
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