Here you have the option of calculating the required cross-section of copper connection cables in the three-phase
three-phase network. Normal three-phase consumers,
such as three-phase motors, are connected here.
How many amps for which cross-section at 400V?
From 5 amperes, a cable with 1.5 mm² is recommended.
From 16 amperes, a cable with 1.5 mm² is recommended .
From 17.3 amperes, a cable with 2.5 mm² is recommended .
From 20 amps, a cable with 2.5 mm² is recommended .
From 23 amps, a cable with 4 mm² is recommended.
From 32 amps, a cable with 6 mm² is recommended .
Please note: The cable calculator provided here is only a rough tool for estimating
the cross-section!
Here is an example:
A 400 V three-phase asynchronous motor has a rated current of 25 amps, a
cos φ of 0.89, a cable length of 94 m and a voltage drop of 2%.
What cable cross-section results from these specifications?
A=(√3 x I x L x cosφ) / (K x Δu x U)
A=(√3 x 25 A x 94 m x 0.89) / (56 x 2 % x 400 V)
A=(3622.48) / (448)
A=8.09 mm²
The next largest suitable cross-section is 10 mm²!
Units of measurement:
Cross-section A=mm²Voltage
U=Volt [V]
Current
i=Ampere [A]
Kappa copper K=56 [m / Ω x mm²]
Delta UΔu = %
cos φ=without
√3 or 1.732=without
