The 5 safety rules of electrical engineering

Disconnection means the electrical installation is disconnected from live parts on all poles. 

Prevent the accidental activation of the system. Re-powering must be reliably prevented. In the low-voltage system, this is preferably done by blocking the actuating mechanism – or you can replace the unscrewed fuses with lockable blocking elements.

Verifying that the installation is dead is performed with a voltage detector. Ensure in advance that the selected voltage detector is suitable for the expected operating voltage, frequency and ambient conditions and check the voltage detector is working correctly. In addition, make sure that voltage detectors for high voltage have been periodically tested. When using a contact voltage tester, uninsulated parts must be contacted in order to establish a reliable electrical contact and to verify the absence of voltage. 

Important: First earth, then short circuit! 
If the system is dead, first connect the earthing and short-circuiting devices (EaS) to the earthing system and then connect them to the parts to be earthed. Disassembly occurs in reverse order to the above. If possible, the earthing and short-circuiting devices must be visible from the work location. Otherwise, they should be placed as close to the work location as possible. 

According to the five safety rules, adjacent parts are parts located in the vicinity zone. 

If there are parts of the system near the work location that cannot be disconnected, you must take additional safety measures before starting work. In this case, use insulating protective shutters or insulating cloths, for example, to protect against accidental contact with live parts.