Siemens SINUMERIK 840D sl Manual page 144

Connection of the Components
5.8 Cable Lengths
All cables inside the cabinet must be connected as closely as possible to parts connected
with cabinet ground, such as a mounting plate or cabinet wall. Ducts made of sheet steel or
routing cables between between steel sheets (e.g. between the mounting plate and back
wall) should provide adequate shielding.
Avoid, where possible, routing unshielded cables, connected to the drive line-up, in the
immediate vicinity of noise sources, e.g. transformers. Signal lines (shielded and unshielded)
connected to the drive line-up, must be routed as far as possible away from strong external
magnetic fields (e.g. transformers, line reactors). In both cases, a distance of ≥ 300 mm is
usually sufficient.
Caution
The Voltage Clamping Module conducts a high leakage current via the functional ground.
This means that a permanent PE connection must be provided for the cabinet (PE) rail.
Measures according to EN 61800-5-1 must be taken e.g. PE conductor ≥10 mm
additional connection terminal for a PE conductor with the same cross-section as the original
PE conductor.
Signal and DC power supply cables
Operating unshielded signal and direct current supply cables (e.g. 24 V infeed with external
supply):
● Direct current supply cables: Max. permissible length: 10 m
● Unshielded signal cables: Max. permissible length: 30 m (without additional wiring)
For greater lengths, suitable wiring must be connected by the user to provide overvoltage
protection. For example:
Table 5-23
DC supply
Weidmüller
Type No.: PU DS 24V 16A
Weidmüller GmbH & Co. KG
An der Talle 89
33102 Paderborn
Tel. 05252/960-0
Fax 05252/960-116
http://www.weidmueller.com
Caution
The connected signal and power cables must not cover the ventilation slots.
5-60
Recommendations for overvoltage protection
24 V signal cables
Weidmüller
Type No.: MCZ OVP TAZ
Guide for the SINUMERIK 840D sl machine configuring
Manual, 07/2006 Edition, 6FC5397-6CP10-0BA0
Cu or fit an
2