Output Wiring; Protective Circuit For Inductive Loads - Panasonic FP0R User Manual

Installation and Wiring
In the actual selection, use a value that is 3 to 5 times the value of W.
Precaution when using an LED-equipped limit switch
If the input of the PLC does not turn off because of the leakage current from the
LED-equipped limit switch, the use of a bleeder resistor is recommended, as shown below.
1
r
A
LED-equipped limit switch
B
FP0R
1 Internal circuit
2 Power supply for input
The OFF voltage of the input is 2.4V. Therefore, when the power supply is 24V, select the
bleeder resistor R so that the current will be greater than the result of this formula:
24 - 2.4
I =
r
The resistance R of the bleeder resistor is:
21.84R
(kΩ)
R ≤
9.1I - 2.4
The wattage W of the resistor is:
(V) 2
W =
R
V = Power supply voltage
In the actual selection, use a value that is 3 to 5 times the value of W.

6.5.2 Output Wiring

There is no fuse in the output circuit. It is recommended to install external fuses in every
circuit, to reduce the risk of burning out the output circuit when the output is shorted.
Do not connect a load that exceeds the maximum switching ability of the output terminal.

6.5.2.1 Protective Circuit for Inductive Loads

With an inductive load, a protective circuit should be installed in parallel with the load.
When switching DC inductive loads with the relay output type, be sure to connect a diode
across the ends of the load.
84
4
3
R
COM
2
3 Bleeder resistor
4 Input terminal
r
Internal resistor of limit switch (k)
R
Bleeder resistor (k)