Technosoft 2019
32
iPOS360x VX-CAN/CAT Technical Reference
3.7.8
Power Supply Connection
3.7.8.1
Supply Connection
Figure 3.28.
Supply connection
3.7.8.2
Recommendations for Supply Wiring
Always provide a nearby capacitor on the motor supply lines. The capacitor should be located within 10cm of the
iPOS360x edge connector, max. 20cm. The minimum recommended capacitance is 330µF for iPOS3604, or 220µF for
iPOS3602, always rated at the appropriate voltage.
Use short, thick wires between the iPOS360x and the motor power supply. Connect power supply wires to all the
indicated pins. If the wires are longer than 2 meters, use twisted wires for the supply and ground return. For wires longer
than 20 meters, add a capacitor of at least 2,200μF (rated at an appropr
iate voltage) right on the terminals of the
iPOS3604, respectively 1,000μF for the iPOS3602
.
3.7.8.3
Recommendations to limit over-voltage during energy regeneration
During abrupt motion decelerations or reversals the regenerative energy is injected into the motor power supply. This
may cause an increase of the motor supply voltage (depending on the power supply characteristics). If the voltage
bypasses 28V, the drive over-voltage protection is triggered and the drive power stage is disabled. In order to avoid this
situation you have 2 options:
Option 1. Add a capacitor on the motor supply
big enough to absorb the overall energy flowing back to the supply.
The capacitor must be rated to a voltage equal or bigger than the maximum expected over-voltage and can be sized
with the formula:
2
2
2
NOM
MAX
M
U
U
E
C
−
×
≥
where:
U
MAX
= 28V is the over-voltage protection limit
U
NOM
is the nominal motor supply voltage
E
M
= the overall energy flowing back to the supply in Joules. In case of a rotary motor and load, E
M
can be
computed with the formula:
F
M
d
d
Ph
2
M
final
initial
L
M
2
M
L
M
M
T
2
t
t
R
3I
)
h
-
)g(h
m
(m
)
J
(J
2
1
E
ϖ
ϖ
−
−
+
+
+
=
where:
Kinetic energy
Copper losses Friction losses
Potential energy