3.9
Wire cross-sections for the supply
If the power supply and drive unit are far apart, wire resistance can result in drops in voltage.
For 24
VAC/DC this can result in the drive receiving insufficient power and thus no longer
starting up. To prevent this, it is important to correctly size the wire cross-section for the
power supply.
The following formulae allow you to calculate the necessary cross-section of the wire or the
maximum wire length for the cross-section being used. Alternatively, a transformer can be
used to increase the secondary voltage.
A = 0.0714 × L : (U
V
– 18
V)
A = wire cross-section [mm
2
]
L = wire length [m]
U
V
= supply voltage [V]
Factor 0.0714 =
drive-specific factor [Vmm
2
/m]
L = A × (U
V
– 21.6
V ) : 0.0714
3 | Device description
58
Translation of the original installation guide · Version 1.0 · 2021-05-27