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For working on equipment under voltage use the guidelines given in EN50110.
Always follow the 5 golden safety rules:
1. Always switch off.
Meaning that the electrical installation must be disconnected from live parts on all poles. Block
all poles of the power source for every part of the operation. Switchgear of home or factory,
low voltage switch mode, the power of the machine control switch should be cut off. The power
supply circuit to be supplied to the electric appliance such as lamps and motors should be cut
off. If you remove the low-voltage rapid fuse, you should wear bracers, a helmet, and front
shields. If there is a capacitor, the residual charge must be discharged using appropriate tools.
2. Secure against reconnection.
Reliably prevent an accidental re-connection of an installation where work is in progress. This
is achieved for example by just replacing the unscrewed fuses in the low-voltage system by
lockable lock-out devices. Appropriate warning signs should be posted for viewing on the
operating device (switch handle, instrument actuator, control device, circuit breaker, etc.). It
should also be posted to closed electrical operating areas or locked switch cabinets. The
contents of the warning cover should warn you that you don’t manipulate the switch. In addition,
provide a name for the workplace location and supervisor. The power-off device should be
locked to a mechanical device. All keys must be kept in a safe place. If it is operated with the
control voltage of the energy or controller, such as springs, compressed air, it must take
measures to prevent the release or operation of energy.
3. Verify that the installation is dead
Use a suitable measuring / test equipment such as a voltage detector to verify on all poles that
the installation is dead. Check the correct function of the voltage detector prior to using it.
4. Carry out earthing and short-circuiting.
An important point of the five safety rules is earthing and short-circuiting at the workplace. This
measure ensures a voltage-free state for the duration of the work, also with regard to
influencing voltages, atmospheric overvoltage or accidental restarting. Earthing and short-
circuit areas should be visible at the workplace. Important: The relevant parts must be earthed
before they are short-circuited!
5. Provide protection against adjacent live parts
According to the five safety rules, adjacent parts are parts located in the vicinity zone. If parts
of an electrical installation in the vicinity zone of the work location cannot be disconnected,
additional precautions must be taken before work starts. In this case use insulating protective
shutters or covering material as protection against accidental contact. The hazard area should
be marked for clarity.
Summary of Contents for PQA8000
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