Siemens S5-135U/155U User Manual

Page 39

3-13

System Manual
C79000-G8576-C199-06

Legend for the table

Lines can be laid in common bundles or cable ducts.

Lines must be laid in separate bundles or cable ducts (without
minimum clearance).

Lines within cabinets must be laid in separate bundles or cable
ducts; outside the cabinets but within buildings, they must be laid
over separate cable routes with a clearance of at least 10 cm.

Lines must be laid in separate bundles or cable ducts with a
clearance of at least 50 cm.

Outside buildings, lay the lines on metal cable trays if possible. Provide the
joints between cable trays with an electrical connection and ground the cable
trays.

When laying lines outside buildings, you must observe the valid lightning
protection and grounding measures. The following applies in general:

Caution

Where cables and lines for SIMATIC S5 controllers are to be laid
outside buildings, you must apply measures for internal and external
lightning protection.

Outside the buildings, lay your lines either

in metal conduit grounded at both ends,
or

in concreted cable ducts with continuously connected reinforcement.

Protect the signal lines from overvoltages by means of

varistors
or

inert gas-filled surge diverters.

Fit these protective devices at the cable entry into the building.

Note

Lightning protection measures always require an individual assessment of
the entire installation. For clarification, please consult your Siemens regional
office or a company specializing in lightning protection.

Ensure adequate equipotential bonding between the connected equipment
(see Section 3.3.2).

Routing of Cables
Outside Buildings

Lightning
Protection

Equipotential
Bonding

Installation Guidelines