Five Safety Rules For Working In Or On Electrical Systems - Siemens Sentron 7KN POWERCENTER 1000 Manual

Safety instructions

2.4 Five safety rules for working in or on electrical systems

• Deactivate all unnecessary functions. If you do not need GPS tracking, for example, you
can deactivate this function.
• Back up your data regularly. Save your backup to another safe place.
• Employees must be conscious of their responsibilities when it comes to cyber security.
Cyber security training courses are advisable for this reason.
2.4 Five safety rules for working in or on electrical systems
A set of rules, which are summarized in DIN VDE 0105 as the "five safety rules", are defined
for working in or on electrical systems as a preventative measure against electrical accidents:
1. Isolate
2. Secure against re-connection
3. Verify absence of operating voltage
4. Ground and short-circuit
5. Provide protection against adjacent live parts
These five safety rules must be applied in the above order prior to starting work on an
electrical system. After completing the work, proceed in the reverse order.
It is assumed that every electrically skilled person is familiar with these rules.
Explanations
1. The isolating distances between live and de-energized parts of the system must vary
according to the operating voltage that is applied.
"Isolate" refers to the all-pole disconnection of live parts.
All-pole disconnection can be achieved, e.g. by.:
- Switching off the miniature circuit breaker
- Switching off the motor circuit breaker
- Unscrewing fusible links
- Removing LV HRC fuses
2. The feeder must be locked against inadvertent reconnection to ensure that it remains
isolated for the duration of the work. This can be achieved, for instance, by locking the
motor and system circuit breakers in the OFF position or by unscrewing the fuses and using
lockable elements to prevent them from being reinserted.
3. The de-energized state of the equipment should be verified using suitable test equipment,
e.g. a two-pole voltmeter. Single-pole test pins are not suitable for this purpose. The
absence of power must be established for all poles, phase to phase, and phase to N/PE.
4. Grounding and short-circuiting are only mandatory if the system has a nominal voltage
greater than 1 kV. In this case, the system should always be grounded first and then
connected to the live parts to be short-circuited.
5. These parts should be covered, or barriers erected around them, to avoid accidental contact
during the work with adjacent parts that are still live.
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Circuit protection devices with communication and metering function
System Manual, 06/2021, L1V30827018B-01