Power Supply; Application - Siemens SINUMERIK ONE NCU 1750 Equipment Manual

Connecting

8.5 Power supply

Note
All cables must be routed vertically upwards to the fullest extent possible so that the front
cover can be closed.
8.5 Power supply
8.5.1

Application

This interface is provided exclusively for connection of the external power supply.
Note
When using external power supplies (e.g. SITOP), the ground potential of the power supply must
be connected with the protective ground connection of the system (PELV).
Note
Ground potential and housing (PE) are connected internally with low impedance.
Interface characteristics
The following special requirements apply to the connecting cables:
• The 24 V DC cable must be approved for temperatures up to 70 °C.
• Select the permitted conductor cross-section in accordance with national regulations (NEC,
VDE,...) from the "X124 interface" table below. The basis for this can be the output current
of the 24 V DC power supply or the overcurrent protection device used in the 24 V circuit. If
the 24 V power supply unit that is used has a short-circuit current greater than 50 A, a
corresponding overcurrent protection device, which limits to this value, must be used
upstream of the product.
• The PE connection must have a minimum conductor cross-section according to EN 60204-1
and a maximum length of 10 m.
• Strip 7 mm of the insulation from the cables for connection to the 24 V DC connector.
• Observe the permissible bending radius of the cables.
• Route all of the cables so that they cannot be crushed or pinched.
• Route all of the cables so that they cannot come into contact with chafing edges.
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Equipment Manual, 01/2022, A5E45627807B AE
NCU 1750