Repair Guidelines - Siemens S5-155U System Manual

S5-135U/155U Central Controller
4.1.4

Repair Guidelines

4 - 14
If measurements or testing become necessary whilst the unit is
operational, accident prevention regulations VBG 4.0 must be
observed, especially the permissible actions when working on active
parts.
Only use tools that are suitable and approved for working on electrical
equipment.
• • Repair of an automation system may only be carried out by the
SIEMENS customer service or by qualified personnel (see
above).
• • Always disconnect the AC power plug or open the isolating switch
before opening the unit. Wait at least 8 minutes before pulling out
and opening a power supply unit (see Section 4.2.3).
• • Parts or components of a central controller may only be replaced
by types listed in Catalog ST 54.1 or in the appendix to this
manual.
• • Fuses may only be replaced by the same type.
• • Instructions for maintenance of the individual components can be
found in the relevant chapters of this manual.
Warning
Unauthorized opening and improper repairs can result in death or
serious personal injury as well as considerable damage.
System Manual
C79000-B8576-C199-03