About the Standard
The norm EN 50110 becomes validity at the year 1996.
The European Committee for Electro technical Standardization worked out this norm.
“CENELEC” is the shortcut of this European Committee.
You can find this norm in three languages – in English, French and also in German.
However, all members of the CENELEC allowed translating the norm to her own language, for example in Italian or Spain.
The purpose of this norm is to provide man of electrical dangers. That means a save operating and a save working on, with or next to electric systems.
The norm consists of two parts.
In the first section, you will find rules, which are building the minimum goal you have to reach. These rules are in all CENELEC countries binding.
In the second part, you will find national rules, which are in most cases much more stricter then the CENELEC rules.
National rules could be stricter as international rules – the opposite of this is not possible.
For example, in Austria, there are laws of the Federation of the Austrians states, and there are also laws of the single states – such as Styria or Carinthia. However, the laws of the single states must be harder then the federation laws – for example the law of protection of animals.
Area of Application
This norm is valid for low-level voltage and for high-level voltage electric systems.
Electric systems served as generating systems, distribution systems, conversions systems or application systems. You can make a difference between fix systems or movable systems.
You also can distinguish between short-time systems or systems for a longer time.
An important factor is, this norm is not only for electro technical man, this norm is also valid for all kinds of workers in the next of electric systems.
That means, all kinds in connection with electric energy are affect from this norm (from the generator to the socket). This norm is also valid for other tradesman’s (joiners, bricklayers…), not alone for electro technical man. This is a large difference between this norm and the older norms.
Movable systems are for example poverty-distribution systems, such as a 400-kVA generator build up of a trailer.

A system to provide building sites with electric energy is demonstrating a short-time system. They stay not longer then a couple of years.
Terms
In the follow, I would describe some special terms, which are used in the norm.
General Terms
Electric Systems – all things that used to generate, distribute, transformation and confirmation electric energy.
That also means batteries, accumulators, capacitors and all other sources with stored energy inside.
Electric systems could be a high voltage network (for example the overland air wires with a voltage to 380 kV) but also a extra low voltage system in a house (for example for the control of a oven).
Operation – that means all technical and organizational occupations who are necessary for an electric system that is work out.
Risk means the probability and the forces of a possible danger of the workers live.
Electrical Dangers (Electrische Gefährdung?)– that is a source of a possibly danger for the workers live in connection with electric systems.
Electric Danger – that means the risk of an injury in nexus with an electric system.
Personnel, Organisation and Communication
Responsible for the Working – one named person, this person is direct responsible for the work. This job can split of more then one person.
If it necessary, the responsible person can pass the responsibility on other electro technical person (deputy).
The responsible for the working is also allowed to work, but he must be all time at the working place.
Responsible for the electric systems – one named person, this person is direct responsible for the operation of the electric systems.
It is also possible to share these function with other colleagues.
Electro technical qualified employee – persons with a qualified training, knowledge and experience who can see dangers in connection with electricity, and avoid this danger.

To practise an electro technical profession could be a condition to become an Electro technical qualified employee, that mean – you must not be an electrician.
Electro technical instructed person – this person is be able to avoid electric dangers.
However, they are only instructed persons, they only know about the instructed dangers.
Layman – these people don’t know anything about electric dangers.
In a electric system you must observe a layman all time. You are responsible for his safety.
Reports – they can be spoken or written. Reports are in nexus with the operation of electric systems.
One important point of reports are the switching of disconnections in electric systems
– for this cases, it gives a strict switch-language.
Working Areas
Working Place – is the place who people work.
Zone of Convergence – this border mark the zone of danger. Working inside this zone is called working under voltage.
Values: to 1kV to 30 kV
0.5 m to 110 kV to 220 kV
1.5 m
2.0 m
3.0 m
4.0 m to 380 kV
Behind this zone, you can work without special precaution. However, you can to rule out, that you never will cross this zone.
Especially by air-wires, you must be very carefully; they often vibrate and could so move in this zone.
Zone of Danger – in this zone application are under voltage.
Operation
Working – all kinds of working, with electricity or without electricity and a possible electrical danger.

Electro technical working – this is working by, with or next to electric systems.
For example building up, checking, rehearsing, measuring or changing of electric systems.
Non-Electro-technical working – this is working in the area of electric systems, not working on this systems. For example painting or cleaning.
Workings under Voltage – all kinds of working with contact to parts, are under voltage.
Workings in the next of Voltage – all kinds of working with contact to parts, are in the zone of convergence.
Switching off - that means a system will be disconnect from the electric network.
Free of voltage – the system is not under voltage, the voltage is zero or near zero, you can work save. You must look of electric influence – because, they can induce also a voltage in a system.
Safety’s Applications
Safety’s Applications are application to prevent a convergence on electric danger systems.
They can build for a short time (during the working) or for a long time (as fix part of the electric system, for example fences around a power station).
Covering means to take of parts of the electric system that you can work save. For example you can use rubber-mats for covering parts in a power station. Important is, the covering prevent of direct contact.
Insulating Covering is the same, but now you also prevent of accidentally contact with under-voltage-parts of the electric system.
Wrapping means, the whole operation-system is prevent of all kinds of influences from outside. You cant contacting the danger parts.
Voltage-levels
Extra-Low-Voltage is a voltage under 50 V AC or 120 V DC.
You can make a difference between Safety Extra Low Voltage (SELV), Protective
Extra Low Voltage (PELV) and Functional Extra Low Voltage (FELV).
Low-Voltage is a voltage und 1000 V AC or 1,500 V DC. This is the normal used voltage level in our houses.

High-Voltage is a voltage above 1000 V AC or 1,500 V DC.
Sometimes you will find the term middle-voltage, which means a voltage level between 1 to 30 kV and is a national term.
Sources: ÖVE-EN 50 110-1, rebuild from Stewaeg-Steg Ink.
Fachkunde Elektrotechnik, Europa Verlag