B&C Technologies DI-325 Industrial - Manual (Page 39)

OPERATING AND PROGRAMMING INSTRUCTIONS
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2.3.2 Output signals on the CPU board
As described in chapter 2.1, the dryer CPU board has 8 digital relay outputs available to
connect signals needed to control the dryer.
Output 1: Heater unit reset
This output can be used to connect a signal to reset the heater installation. Every time a new
drying program is started, this output will be activated for the time adjusted in machine parameter
30 (see chapter ‘Machine parameters’).
Output 2: Status output
This output is used to indicate the current status of the machine. How the output is
controlled, is adjustable with configuration parameter 12 (see chapter ‘Configuration parameters’).
It can be used to indicate a drying cycle is busy, to indicate a cycle has been finished or to indicate
an alarm is active. A combination of these states is also possible.
Output 3: Blower cleaning signal
This output is activated every time the start button is pushed. If the start button is pushed,
the output is activated for the time adjusted in machine parameter 31 (see chapter ‘Machine
parameters’). Usually, this output is connected to an air-blast signal to clean the blower.
Output 4: Blower WYE switch
In large machines (with large blower motors) a WYE switch may be used to decrease the
start-up current used by the blower motor. When the blower motor is off or during the first time
after starting up (time adjustable in machine parameter 32, see chapter ‘Machine parameters’), this
output will be off. When the blower motor has run for the time adjusted in machine parameter 32,
this output will switch on. So, use this output to switch the star/delta switch.
Output 5: Drum motor direction left
If the dryer has a reversible drum, this is the output for letting the drum run in the left
direction. If the dryer drum has only one direction, this is also the output for letting the drum run,
although the motor can also be connected together with the blower to output 6 in this case. The
presence (or absence) of a reversible drum can be indicated with configuration parameter 7 (see
chapter ‘Configuration parameters’).
Output 6: Drum motor direction right
If the dryer has a reversible drum, this is the output for letting the drum run in the right
direction. The presence of a reversible drum can be indicated with configuration parameter 7 (see
chapter ‘Configuration parameters’).
Output 7: Blower
The output of the blower motor, this output will be continuously on when a drying or cool-
down cycle is busy and the dryer is running. This output can also be used to connect the drum
movement in case the drum isn’t reversible.
Output 8: Heating
The output for heating. If the machine is running, a temperature control function will decide
if heating is necessary, depending on the adjusted goal temperature and the current temperature(s).
If heating is necessary, the output will be on, otherwise it will be off.
Output 8 is an output with a normally closed contact and a normally opened contact. The
normally opened contact is usually used for the heater. If necessary, the normally closed contact can
be used for, for example an ‘air recirculation’ valve.