Mitsubishi Electric NZ2MF2S1-32D User Manual page 70

Precautions when using the transistor output module
■Measures against reverse current
In the following connections, a reverse current flows to the output element, which can cause failure.
When wiring, set up diodes as the following figures show:
• When connecting transistor output modules in parallel
Sink type
Load
OUT1
Load
OUT2
COM
OUT1
OUT2
COM
• When providing another circuit in parallel with a transistor output module
Sink type
Additional circuit
OUT
COM
■Measures against back EMF
When connecting an inductive load, connect a diode in parallel with the load.
Use the diode that satisfies the following conditions:
• A reverse breakdown voltage is ten or more times as high as the circuit voltage.
• A forward current is two or more times as high as the load current.
Sink type
Inductive
OUT
load
COM
■About element protection of the output module
If excessive noise affects the terminals of the output module, the output may be turned on to help the protection of the output
element. Adjust the voltage between terminals of the output module to fall within the operating load voltage range by taking
measures such as the following:
• To use an inductive load such as a relay, a surge suppressor is required on the load side as well. Take appropriate
measures with the measures against back EMF as a guide.
• To prevent excessive noise, avoid installing power cables together with I/O cables.
6 INSTALLATION AND WIRING
68
6.1 Before Using the I/O Modules
Source type
Load
OUT1
Load
OUT2
COM
OUT1
OUT2
COM
Source type
Additional circuit
OUT
COM
Source type
Inductive
OUT
load
COM