B&C Technologies M720 Dryer Control (DE, DP, DI Series) - Manual (Page 44)

Also please note that if the lint filter door or drawer is opened when a program is running
the air flow will change which can also cause the switch to open. In this case an additional
air flow sensor error will be given.
• Temperature sensor 1 error
The cable of temperature sensor 1 is broken or there is a short circuit, or the sensor has failed.
The controller detects that the sensor is not properly connected or is malfuntioning.
• Temperature sensor 2 error
The cable of temperature sensor 2 is broken or there is a short circuit, or the sensor has failed.
The controller detects that the sensor is not properly connected or is malfuntioning. This
message will only be displayed in case the presence of a second temperature sensor is set in
the machine configuration parameters (see Section 4.9, parameter 4). The machine is still
able to run in case the 2
nd sensor is broken, but it cannot run on automatic drying any more
(see Section 4.5.1, program parameter 1). In order to run the machine the sensor should be
replaced or a program with time-based drying should be chosen.
• Error power supply
The 24V power supply is too low (below 20 Volts) or too high (above 40 Volts). Because this
can cause damage to the controller, it has switched all outputs off. The actual power supply
voltage can be checked at any time from the test program menu (see Section 4.6.4 on page
32).
• Battery empty
When starting up the controller checks if the battery backed-up memory is correct. If not, this
message will be displayed. This message will only be displayed after startup. The battery
capacity is enough for 1 year, so it is strongly recommended to replace the battery yearly. The
S TART key must be pressed to reset the message.
• Microprocessor restarted
The dryer controller is able to monitor its power supply. If the power supply voltage is too
low, or too high, alarm 18 will be displayed. If the power supply voltage is too low for the
controller to be able to operate the microprocessor will reset itself. This can happen in case of
a sudden, brief voltage drop. If this happens the microprocessor will store this and the next
time the controller starts up, alarm 20 will be shown on the display.
• Infra-red sensor read error
The presence of an infra-red sensor has been indicated in the machine configuration param-
eters (see Section 4.9 on page 35, parameter 5), but the controller cannot detect a working
infra-red sensor. This means it cannot determine the batch is dry. The machine is still able
to run in case the infra-red sensor is broken, but it cannot run on automatic drying any more
. In order to run the machine, the sensor should be replaced or a program with time-based
drying should be chosen.
• Humidity sensor read error
The presence of a humidity sensor has been indicated in the machine configuration parame-
ters (see 4.9 on page 35), but the controller cannot detect a working humidity sensor. This
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