6.4
GALVANIC ISOLATION BARRIERS
The control connections are isolated from mains. The GND terminals are permanently
connected to I/O ground. See Fig. 27 The galvanic isolation barriers.
The digital inputs on the I/O board are galvanically isolated from the I/O ground. The relay
outputs are also double-isolated from each other at 300VAC (EN-50178).
10V
ref
L1 L2 L3
U V W
GND
AI1
GND
Control I/O
ground
Gate drivers
Control
panel
Control
unit
Power unit
Digital
input
group A
Digital
input
group B
Analogue
input
Digital
input
+24V
AI2-
AI2+
AO2-
DO1
AO1+
DIN3
CMA
DIN1...
DIN6
CMB
DIN4...
RO1/2
RO1/3
RI1/1
RO2/2
RO2/3
TI1+
TI1-
RO2/1
Fig. 27: The galvanic isolation barriers
VACON · 76
CONTROL UNIT
6
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