Nidec Commander C300 Power Installation Manual page 91

Figure 4-27 Surge suppression for digital and unipolar inputs and outputs
Figure 4-28 Surge suppression for analog and bipolar inputs and outputs
Surge suppression devices are available as rail-mounting modules, e.g. from Phoenix Contact:
Unipolar TT-UKK5-D/24 DC
Bipolar TT-UKK5-D/24 AC
These devices are not suitable for encoder signals or fast digital data networks because the
capacitance of the diodes adversely affects the signal. Most encoders have galvanic isolation of the
signal circuit from the motor frame, in which case no precautions are required. For data networks,
follow the specific recommendations for the particular network.
Unidrive M / HS Frame 7 to 10 Power Installation Guide
Signal from plant
0V
Signal from plant
0V
Signal to drive
30V zener diode
e.g. 2xBZW50-15
0V
Signal to drive
2 x 15V zener diode
e.g. 2xBZW50-15
0V
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