Labour protection laws obligate!
Employers are responsible for the health and safety of their employees. According to labour protection laws, employers must ensure that all necessary protection measures are taken and observed when working on electrical installations.
Therefore the relevant parts of an installation are isolated from supply voltage when working on electrical installations and equipment. However, simply hitting a switch for isolation from supply voltage is by far not enough. From isolating the installation from supply voltage to releasing the work location, further reliable information on the state of the installation, measures to prevent maloperations and malfunctions, protection against maloperations and malfunctions as well as protection against risk potentials of adjacent parts of the installation is required. For this purpose the following five safety rules in accordance with EN 50 110-1 have to be observed:
- Disconnect completely
- Secure against re-connection
- Verify that the installation is dead
- Carry out earthing and short-circuiting
- Provide protection against adjacent live parts.
Every certified electrician knows that these rules can save his life. But what about the safety and reliability of devices and tools used to gain vital information or secure sequences of operation? Every measure is only as safe as the safety devices used.