# Why does an electric motor, of 800 kW at 400 V, have 7 connectors for power cables?

I found a Vybo electric motor and noticed that it has seven connectors for power cables. I also found a Variable Speed Drive, Altivar Process ATV900, System ATV960, 800/630 kW, 400 V and its datasheet lists many characteristics out of which I mention:

• Motor power: 800 kW,

• Continuous output current: 1420 A at 2.5 kHz,

• Line current: 1335 A at 400 V,

• Motor recommended cable cross section: 6 x (3 x 185 mm²) or 5 x (3 x 240 mm²).

Question: Should I understand that the Vybo motor in question needs 6 three phase cables, each of them with 3 conductors of 185 mm² in cross section, or 5 cables with three conductors of 240 mm², each; independently of the fact that the motor is powered from the VSD or directedly from the 400 V, 50 Hz industrial source?

• Do you think those 7 things are connectors? Or could they be cable glands with the actual connectors inside? And 7 to allow for control and sensing cables as well as power cables? Aug 1, 2022 at 7:18
• It does sound like each of the 3 internal coils are controlled fully separately with a high current connector, plus a protective earth. Aug 1, 2022 at 8:18
• @SolarMike , They are cable glands. However, according to this guide (see: sghcable.com/pdf/cable_usage/App-2E%20V2.pdf) a 3-ph AC cable can carry min 245 A/ phase. So, six 3-ph AC cables in parallel (with all 6 phases a ( and b, c) connected together at ends) carry 245 A x 6 = 1470 A/phase. Now, if we go back to the 800 kW motor and calculate its line currents in ideal conditions, we get: I = 800kW/(400V*sqrt(3))= 1154 Amp, so the 6 AC cables mentioned above are well suited to power this motor. This is an explanation found by my for the 7 glands of the motor but I might be wrong. Aug 1, 2022 at 14:39