Proface LT4300M - 5.7 Modular HMI + Control" - Manual (Page 34)

LT System General Implementation Rules
34
Protecting Outputs from Inductive Load Damage
Depending on the load, a protection circuit may be needed for the outputs on the controllers and
certain modules. Inductive loads using DC voltages may create voltage reflections resulting in
overshoot that will damage or shorten the life of output devices.
Protective circuit A: this protection circuit can be used for DC load power circuits and source
outputs (positive logic).
Protective circuit A: this protection circuit can be used for DC load power circuits and sink outputs
(negative logic).
 C represents a value from 0.1 to 1 μF.
 R represents a resistor of approximately the same resistance value as the load.
Protective circuit B: this protection circuit can be used for DC load power circuits and source
outputs (positive logic).
CAUTION
OUTPUT CIRCUIT DAMAGE DUE TO INDUCTIVE LOADS
Use an appropriate external protective circuit or device to reduce the risk of inductive direct
current load damage.
Failure to follow these instructions can result in injury or equipment damage.