Chapter 7 Wiring Diagrams and Signal Information
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♦ LVPS overcurrent protection circuit
This circuit stops all outputs, if the power supply voltage 24VDC, 5V DC, or 3.3VDC is shorted.
The circuit is reset, when after the cause of short was removed, the power is turned off, and then on
again after certain time.
♦ LVPS overvoltage protection circuit
This circuit stops all outputs, if the power supply voltage 24VDC, 5V DC, or 3.3VDC exceeds the
specified voltage respectively.
At this time, the operating point is 32VDC or less for 24VDC, 7VDC or less for 5VDC, or 6V or les s
for 3.3VDC.
The circuit is reset, when the power is turned off, and then on again after certain tim e.
♦ FAN output circuit
For the FAN REAR ON (H) signal, the output voltage varies depending on the status of FAN LOW
signal and FAN STOP signal.
♦ Output stop by Interlock Switch
Turning off the Interlock Switch mounted on the PWBA HNB DRV causes the "I/L +24VDC" circuit to
be shut off. Consequently, +24VDC supply to the PWBA HNB MCU and to the parts connected to the
PWBA HNB DRV is stopped.
Signal line name Description
FAN LOW FAN REAR drive control signals
FAN STO P
FAN REAR FAIL(H)+3.3VDC FAN REAR fail detection signal (High: Fail, Low: Normal)
FAN REAR ON(H) FAN REAR ON/OFF control signal
FAN LOW FAN STOP FAN REAR ON(H)
High High 24V
Low High 15V
High Low 0V
Low Low 0V