Mitsubishi Electric MELSEC iQ-R Series User Manual page 104

■Measures for connecting an inductive load
To connect an inductive load, take measures to reduce noise to the side where the load is connected as shown below.
Circuit example
Varistor method
Output module
Capacitor +
Output module
resistance method
(CR method)
■Measures for connecting an inductive load (when installing a contact between the load and
the output terminal)
To install a contact (such as an interlock) between the load and the output terminal, take measures to reduce noise as shown
below.
Though measures (varistor method, capacitor + resistance method) are normally taken to the load side, in some cases, it is
more efficient to take the measures to the module side considering the contact effect.
Circuit example
Varistor method • Measure taken to the load side
• Measure taken to the module side
Output module
6 INSTALLATION AND WIRING
102
6.1 Before Using the I/O Modules
Varistor
Capacitor
Resistor
Output module
Contact
Varistor
Contact
Varistor
Element selection criteria
Select a varistor whose cut-off voltage (Vc)
satisfies the following conditions:
• Vc > Power supply voltage  1.5 (V)  2
Note that selecting an element of a too high
Inductive
Vc leads to a weaker effect.
load
Estimate the constants of a capacitor and
resistance with the following as a guide.
Some differences, however, may arise from
a variation in the nature and characteristics
Inductive
of the load.
load
• Capacitor: 0.5 to 1 (F) for a load current
of 1A
• Resistance: 0.5 to 1 () for a power
supply voltage of 1V
Use a capacitor whose withstand voltage is
equal to or higher than the rated voltage.
Use a capacitor with no polarity.
Element selection criteria
Select a varistor whose cut-off voltage (Vc)
satisfies the following conditions:
• Vc > Power supply voltage  1.5 (V)  2
Note that selecting an element of a too high
Vc leads to a weaker effect.
Inductive
load
Inductive
load
Remarks
The recovery time is a little delayed.
When a relay or solenoid is used as
the load, the recovery time is delayed.
Remarks
The recovery time is a little
delayed.