Vacon NXI Series - Control Cables

40 • vacon cabling and connections
Tel: +358-201-2121 • Fax: +358-201-212 205
6
Figure  6-11. General wiring diagram of the basic relay boards (NXOPTA2/NXOPTA3)
6.2.1.1 Control cables
The control cables shall be at least 0.5 mm
2
screened multicore cables, see Table 6-8. The
maximum terminal wire size is 2.5 mm
2
for the relay terminals and 1.5 mm
2
for other terminals.
You can find the tightening torques of the option board terminals below.
Terminal screw
Tightening torque
Nm
lb-in.
Relay and
thermistor
terminals
(screw M3)
0.5
4.5
Other terminals
(screw M2.6)
0.2
1.8
Table  6-8. Tightening torques of terminals
6.2.1.2 Galvanic isolation barriers
The control connections are isolated from the mains potential and the GND terminals are
permanently connected to ground. See below.
The digital inputs are galvanically isolated from the I/O ground. The relay outputs are additionally
double-isolated from each other at 300VAC (EN-50178).
Figure  6-12. Galvanic isolation barriers
DC+ DC-
U V W
RO1/1
RO1/2
RO1/3
RO2/3
RO2/2
RO2/1
10Vref
GND
GND
+24V
AI1
AI2+
AI2 -
DIN1...
DIN3
CMA
DIN4...
DIN6
CMB
AO1+
AO2 -
DO1
nk6_15
TI1+
TI1-
Control I/O
ground
Digital input
group A
Digital input
group B
Analogue
output
Digital
output
Control
board
Control
panel
Gate drivers
Power
board