B&C Technologies M720 Dryer Control (DE, DP, DI Series) - Manual (Page 43)

The input for the error of the frequency inverter (input 11) is configured to be a pulse train
input. This means that the controller must detect a certain pattern on this input signal. If
not, the machine is stopped out of safety issues because if this pulse train is not detected, a
malfunction of this signal can be possible.
• Control panel blocked
In some circumstances, it is possible that the controller locks itself. If this happens, an un-
locking code must be entered. This can be done via the System Setup menu (see Section
4.7.5) or by switch the controller off and on again. In the Enter unlocking code screen, the
unlocking code can be entered. Contact the manufacturer for the right unlocking code.
• Gas heater alarm
The input for the error of the gas heater (input 14) is, or has been, in the off state for minimum
3 seconds. This means the gas heater gives an error signal.
• Fire suppression
The input for fire suppression (input 15) is, or has been, in the off state. This means the fire
suppression contact is activated.
• Rotation sensor time-out
While the drum was running, the rotation sensor didnt go from the on to the off state quickly
enough. This can mean the drum is jammed or the drum motor isnt working properly.
• No air pressure
The input for the air pressure switch (input 8) is, or has been, in the off state. This means the
airflow is insufficient, or the airflow switch is not operating properly.
• Lint filter door opened
The input to detect if the lint filter door or drawer is closed (input 2) is, or has been, in the off
state. This means that the lint filter door or drawer has been opened.
• Door opened
The input to detect if the door is closed (input 1) has been in the off state while it should be in
the on state. The controller checks if the door is closed when a program is started and when
a program is running. If the door is opened, this message will be displayed.
• Air flow sensor error
The input which monitors air flow (input 3) is not detecting the expected signal. When the
machine is started the input should be in the off state. After the blower is started the input
should change to the on state in the time defined in machine parameter 33. If the input is
in the on state when starting up, or does not go to the on state in time then no air flow is
detected. As this situation can be dangerous the machine is stopped.
Please note that if a dryer is stopped and then restarted quickly this message can appear.
Because of the momentum of the blower motor air will still be flowing and the switch will
stay in the on state, for a short time after the blower motor has been stopped. If the machine
is started again during this period this message will also be displayed.
40