
Unidrive M / HS Frame 7 to 10 Power Installation Guide
87
Issue Number: 5
S
P
M
El
Te
UL
list
ing
in
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.
Signal from plant
Signal to drive
0V
0V
30V zener diode
e.g. 2xBZW50-15
Signal from plant
Signal to drive
0V
0V
2 x 15V zener diode
e.g. 2xBZW50-15
Unidrive M frame7 to 10 Power Installation Guide issue5.book Page 87 Tuesday, May 24, 2016 11:52 AM