Earthing of the supply

Earthing of the supply 1:

No fuses exist

The figure below is for illustration purposes only. No necessary fuses exist or are pictured in the simplified illustration.

Earthing of the supply 2:

Control circuit

The EN60204-1 standard, clause 9.4.3.1. Earth faults stipulates that 24 VDC control circuits must be earthed. The earthing prevents the automatic start-up of a machine in the case of a cross-circuit.

Earthing of the supply 3:

Load current circuit

Earthing of the supply 4:

Beckhoff recommends that you don't earth the 48 V power supply unit

The 24 VDC return line (1.5 mm2) could be overloaded.

If the 48 V power supply unit is earthed, the currents will be distributed to the 48 VDC and 24 VDC back wires in accordance with the impedances. Equalizing currents will then flow via the earth on the power supply unit, as a result of which the 24 VDC return line (1.5 mm2) could be overloaded.