Panasonic FP-M Hardware Manual page 62

4-3. Wiring
Output wiring examples
• Connect a protective circuit such as the one shown below when switching inductive loads.
When switching DC type inductive loads with a relay output type, be sure to connect a diode across the ends of the
load.
When using an AC inductive load
Output
terminal
FP-M
AC inductive load
COM
When using a DC inductive load
Output
terminal
FP-M
DC inductive load
0 V or
COM
When using a capacitive load
Output
terminal
FP-M
0 V or
COM
• Mounting the protective device
In the actual circuit, it is necessary to locate the protective device (diode, resistor, capacitor, varister, etc.) in the
immediate vicinity of the load or contact. If located too far away, the effectiveness of the protective device may
diminish. As a guide, the distance should be within 50 cm (19.685 in.).
• Type of load and inrush current
The type of load and its inrush current
characteristics, together with the
switching frequency are important
factors which cause contact welding.
Particularly for loads with inrush
currents, measure the steady state
current and inrush current and use a
relay or magnet switch which provides
an ample margin of safety. The table on
the right shows the relationship between
typical loads and their inrush currents.
54
Surge absorber
R C
Example:
R: 50 Ω
C: 0.47 µF
Diode
Resistor
Capacitive load
Output
terminal
FP-M
COM
Output
terminal
FP-M
0 V or
COM
Type of load
Resistive load Steady state current
10 to 20 times the
Solenoid load
steady state current
5 to 10 times the
Motor load
steady state current
10 to 15 times the
Incandescent lamp load
steady state current
Approx. 3 times the
Mercury lamp load
steady state current
1 to 3 times the
Sodium vapor lamp load
steady state current
20 to 40 times the
Capacitive load
steady state current
5 to 15 times the
Transformer load
steady state current
Varister
AC inductive load
Coil
Capacitive load
Inrush current