SIST EN 50308:2004

SLOVENSKI SIST EN 50308:2004

STANDARD
september 2004
Vetrne turbine – Zaščitni ukrepi – Zahteve za načrtovanje, delovanje in
vzdrževanje
Wind turbines - Protective measures - Requirements for design, operation and
maintenance
ICS 27.180 Referenčna številka
SIST EN 50308:2004(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

---------------------- Page: 1 ----------------------

EUROPEAN STANDARD EN 50308
NORME EUROPÉENNE
EUROPÄISCHE NORM July 2004

ICS 27.180


English version


Wind turbines –
Protective measures –
Requirements for design, operation and maintenance


Aérogénérateurs –  Windenergieanlagen –
Mesures de protection – Schutzmaßnahmen –
Exigences pour la conception, Anforderungen für Konstruktion,
le fonctionnement et la maintenance Betrieb und Wartung






This European Standard was approved by CENELEC on 2004-03-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 50308:2004 E

---------------------- Page: 2 ----------------------

EN 50308:2004 – 2 –
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 88, Wind turbine
systems. This standard concerning protective measures stands in conjunction with the set of European
standards for wind turbines (EN 61400 series).
The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50308 on
2004-03-01.
The following dates were fixed:
- latest date by which the EN has to be implemented
 at national level by publication of an identical
 national standard or by endorsement (dop) 2005-03-01
- latest date by which the national standards conflicting
 with the EN have to be withdrawn (dow) 2007-03-01
This European Standard was prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and supports the essential requirements of
Directive 98/37/EC
NOTE Revision of this standard will be undertaken as soon as possible.
__________

---------------------- Page: 3 ----------------------

– 3 – EN 50308:2004
Contents
Introduction.4
1 Scope.5
2 Normative references.5
3 Definitions - Terminology .6
4 Safety requirements and protective measures .7
4.1 General requirements .7
4.2 Passages .7
4.3 Rooms / working areas .9
4.4 Floors, platforms, standing-, working places.9
4.5 Climbing facilities .10
4.6 Moving parts, guards and blocking devices .13
4.7 Lighting .13
4.8 Noise.14
4.9 Emergency stop.15
4.10 Power disconnection.15
4.11 Fire protection .16
4.12 Warning signs .16
4.13 Offshore installation.16
4.14 Requirements for manuals and warnings.17
4.15 Requirements for operation and maintenance (Information for use) .19

Annex A (informative) National informative annexes .21
A.0 Introduction.21
A.1 Germany (DE).21
A.2 Denmark (DK).22
A.3 Spain (ES) .22
A.4 France (FR) .23
A.5 United Kingdom (GB) .24
A.6 Greece (GR) .24
A.7 Ireland (IE).24
A.8 Italy (IT) .24
A.9 The Netherlands (NL).25

---------------------- Page: 4 ----------------------

EN 50308:2004 – 4 –
Introduction
This European Standard has been prepared as a harmonised standard to provide a means of conforming
to the essential safety requirements of the Machinery Directive and associated EFTA regulations. For the
determination of the hazards described in this standard EN 1050 should be applied.
The machinery concerned and the extent to which hazards, hazardous situations and events are covered
is indicated in Clause 1 (Scope).
This standard is a product (family) standard (according to EN 292-1) giving common requirements for the
wind turbines mentioned in Clause 1 (Scope).
The document contains a standard part and an informative annex.
Annex A consists of national normative documents and/or regulations that specify either the present
safety requirements for personnel or give the national supplements to these minimum requirements at the
time this standard was prepared (January 2000).
The format of the standard is based, where possible, on a practical approach for
– manufacturers and designers who have to meet the requirements,
– authorities who have to check the design,
– owners who have legal responsibilities.

---------------------- Page: 5 ----------------------

– 5 – EN 50308:2004
1 Scope
This European Standard specifies requirements for protective measures relating to the health and safety
of personnel, relevant to commissioning, operation and maintenance of wind turbines.
It does not describe instructions and provisions for safe working during manufacture, transport, assembly
and installation of the wind turbine.
Requirements are specified regarding
– hardware provisions being a part of the turbine such as platforms, ladders, lighting,
– manuals and warning signs to accommodate safe and quick operation, inspection and maintenance.
The requirements and/or measures specified account for the hazards
– of mechanical origin such as falling, slipping, locking in,
– of thermal origin (fire) such as burns by flames or explosions,
– of electricity such as contact with live parts,
– generated by noise such as stress and loss of hearing,
– generated by neglecting ergonomic principles in machine design such as unhealthy postures or human
errors.
This standard is prepared for horizontal axis, grid connected wind turbines. For other concepts (e.g.
vertical axis turbines) the principles are still valid, but the specific rules or requirements have to be
adjusted to the actual concept.
Additional provisions and procedures are necessary for turbines installed in water or offshore. The present
document only draws attention to these.
Provisions and procedures for lifts and Suspended Access Equipment (SAE) in the turbine tower are not
included in this standard.
This standard is not applicable to wind turbines manufactured before the date of its publication by
CENELEC.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 292-1 Safety of machinery - Basic concepts, general principles for design
Part 1: Basic terminology, methodology
EN 292-2 1991 Part 2: Technical principles and specifications
EN 418 Safety of machinery - Emergency stop equipment, functional aspects
Principles for design
EN 457 1992 Safety of machinery - Auditory danger signals
General requirements, design and testing (ISO 7731:1986, mod.)
EN 547-1 Safety of machinery - Human body dimensions
Part 1: Principles for determining the dimensions required for openings for
whole body access into machinery

---------------------- Page: 6 ----------------------

EN 50308:2004 – 6 –
EN 547-3 Safety of machinery - Human body dimensions
Part 3: Anthropometric data for whole body access into machinery and access
openings
EN 563 Safety of machinery – Temperatures of touchable surfaces
Ergonomics data to establish temperature limit values for hot surfaces
EN 795 Personal protective equipment against falls from a height
Anchorage devices - Requirements and testing
EN 953 Safety of machinery – Guards – General requirements for the design and
construction of fixed and movable guards
EN 981 Safety of machinery – System of auditory and visual danger information
signals
EN 982 Safety of machinery - Safety requirements for hydraulic and pneumatic
systems and parts - Hydraulics
EN 983 Safety of machinery - Safety requirements for hydraulic and pneumatic
systems and parts - Pneumatics
EN 1037 Safety of machinery – Prevention of unexpected start up
EN 1050 Safety of machinery – Principles for risk assessment
ISO 4871 1996 Acoustics – Determination of sound power levels of noise sources using
sound pressure – Engineering method in an essentially free field over a
reflecting plane

EN ISO 11202 1995 Acoustics – Noise emitted by machinery and equipment – Measurement of
emission sound pressure levels at a work station and at other specified
positions – Survey method in situ

Acoustics – Recommended practice for the design of low-noise machinery
EN ISO 11688-1 1998
and equipment - Part 1: Planning
1)
EN ISO 14122-1 Safety of machinery
Part 1: Permanent means of access to machines and industrial plants -
Choice of a fixed means of access between two levels
1)
EN ISO 14122-2 Part 2: Working platforms and gangways
1)
EN ISO 14122-3 Part 3: Stairways, stepladders and guard-rails
1)
EN ISO 14122-4 Part 4: Fixed ladders
EN 50160 Voltage characteristics of electricity supplied by public distribution systems
EN 50172 Emergency escape lighting systems

EN 50199 Electromagnetic compatibility (EMC) - Product standard for arc welding
equipment
ENV 1070 Safety of machinery – Terminology
ENV 61400-1 Wind turbine generating systems - Part 1: Safety requirements
EN 61400-11 1998 Wind turbine generator systems – Part 11: Acoustic noise measurement
techniques (IEC 61400-11:1998)
HD 472 Nominal voltages for low-voltage public electricity supply systems
(IEC 60038, mod.)
3 Definitions – Terminology
For the purpose of this standard the definitions given in EN 292, ENV 61400-1 and EN ISO 4871 apply.

1)
At draft stage.

---------------------- Page: 7 ----------------------

– 7 – EN 50308:2004
4 Safety requirements and protective measures
4.1 General requirements
Wind turbines shall be designed according the principles of EN 292. The general principles to avoid risks
to health and safety are laid down in Clause 5 of EN 292-1 (Strategy for selecting safety measures).
The initial design of wind turbines must take account of how risks to the health and safety of persons are
to be minimised. Structural provisions include e.g. door-openings, access-openings, floors, platforms and
railings, ladders with fall protection equipment, passages and working spaces, anchorage points and hand
grips, lighting, guarding of moving parts, protection against electrical hazards, sound barriers, noise
isolation or thermal isolation. Some of these provisions have an effect on the structural integrity of the
turbine e.g. door openings, doorstep height, access openings.
The design shall include provisions for permanent safe access (ladders, platforms, anchorage points,
lighting, etc.) to reach the locations for inspection and maintenance activities and to perform these
activities safely. All items shall be safe during the turbine lifetime (providing that they are maintained
according to the operator's instruction manual and maintenance manual for the turbine).
Accessible parts of the machinery shall have no sharp edges, no sharp angles and no rough surfaces
likely to cause injury.
Normal control of the wind turbine shall be possible without ascending to the turbine nacelle.
Control panels shall be placed so that unintentional or erroneous operation is prevented. If a wind turbine
has more than one control panel/unit, it shall only be possible to operate it from one panel/unit at a time.
Where remote operation of a wind turbine is possible (e.g. via a modem link) a local control switch shall
be available to cut off the remote mode and all other control systems in the turbine with the exception of
any emergency stop.
It shall be possible to block, vent, release or isolate/disconnect any stored or trapped energy that can
cause risk during maintenance where parts of the turbine are powered by an energy source other than
wind, such as
– electrical energy inside a capacitor bank or battery,
– mechanical energy inside a spring loaded system or brake system,
– hydraulic energy inside pressurised accumulators,
– gravity.
EN 982 shall be followed to release stored energy.
EN 1037 shall be followed to prevent unexpected start–up.
4.2 Passages
Doors, hatches, access and escape passages shall be in accordance with 6.0 of EN 292-2.
Dimensions are based on EN 547-1 and EN 547-3.
4.2.1 Access
All normal access points to wind turbines shall be equipped by the manufacturer with means to make the
turbines inaccessible, so as to prevent unauthorised persons from gaining access. In particular, access to
the control panel, the machinery and electrical parts of the wind turbine by unauthorised persons shall be
prevented.

---------------------- Page: 8 ----------------------

EN 50308:2004 – 8 –
Access ways, passages, doors and climbing provisions shall be designed with personnel safety in mind.
They shall not to be obstructed by fixed auxiliary appliances, piping, wiring or by stored items.
Doors being the entrance to the turbine and/or to rooms with electrical switch gear (having an escape
function) shall have
– provision of unobstructed passage at least 0,6 m wide, which may have rounded off corners,
– no sharp edges likely to cause injury,
– a (additionally installed) horizontal part to step on of at least 0,3 m wide,
– a platform or floor inside and outside with a difference of level of no more than 0,1 m,
– the capability of opening immediately, without the use of tools/keys,
– the capability to prevent persons from being locked inside,
– a door grip on both sides,
– the capability of being secured in the open position.
The lowest part of the doorsteps shall have a maximum height of 0,3 m above standing level and give a
free opening height of 1,8 m minimum.
Nacelle covers that can be opened, doors and hatches affected by wind or gravity shall be capable of
being secured in the open as well in the closed position. They shall be designed to be held securely open
in wind speeds up to the maximum wind speed allowable for maintenance of the turbine, including
allowance for gusts.
Foot supports and hand grips shall be available alongside any passage through a wall if no platform is
installed there.
Hatch openings in a wall for entry by a person shall have a minimum free opening of 0,4 m x 0,6 m. In a
floor they shall have a minimum free opening of 0,6 m x 0,6 m. If structurally governed, reduction to a size
of 0,4 m x 0,6 m is permitted. Alternatively a trapezoidal shape is permitted. The corners of these
openings may be rounded off.
Openings through floors and platforms shall have a hinged cover, which shall have two stable positions:
open and closed.
4.2.2 Escape
An alternative escape route from the nacelle shall be available if the normal access route can be blocked
(e.g. by fire). This alternative escape route shall be indicated by signs and be described in the user
(safety) manual. The escape route shall be designed free of any obstructions. The means of escape can
be a ladder or a descent device. An appropriate descent device shall be chosen for specific turbine types
and heights. A device shall be fire proof enough to allow escape from the nacelle to the ground in the
event of fire. It shall be suitable for the number of persons to be evacuated. Descent devices can be either
permanently located in the turbine or brought by personnel.
An anchorage point shall be available for every descent device (see 4.5).
The escape route from working areas in front of electrical switch gear shall offer unobstructed passage
according to the requirements in EN 50199.
Provision shall be made to evacuate an injured person from any room or area, including the nacelle,
occupied for work or inspections.
The nacelle shall have an extra hatch to the outside apart from the normal entrance. It shall be possible to
open this hatch from both inside and outside.

---------------------- Page: 9 ----------------------

– 9 – EN 50308:2004
Hatches for the emergency descent of personnel shall be located to ensure easy evacuation. They must
be designed not to present any risk of persons accidentally falling from the nacelle. The minimum
dimensions shall be 0,6 m x 0,6 m. The corners in the passage opening may be rounded off. An
anchorage point shall be provided near the emergency hatch.
4.3 Rooms / working areas
Rooms or areas where work or inspections have to be done shall fulfil the requirements of EN 547-1 and
EN 547-3.
Auxiliary electrical connection points for light and power shall normally be provided in rooms or areas
where work or inspections have to be done. Auxiliary power shall normally be available when the turbine
itself is electrically isolated.
An operating room, a low voltage and a medium voltage switch room inside a tower shall be protected with
a ceiling/floor directly above (medium voltage is 1 kV to 35 kV, according to EN 50160 and HD 472). If an
operating room or a medium voltage room is equipped with electrical switch gear the working-space in
front of the electrical cabinets shall be at least 0,75 m wide and 2,0 m high.
Measures shall be taken to avoid the build up of hazardous toxic, flammable or explosive gases in any
areas of the wind turbine. If a power transformer is installed these measures shall include sealing
arrangements of the transformer room or the provision of adequate ventilation, also in the situation of a
grid loss.
Provisions shall be made to store in a safe and secure way any specialist working equipment, safety
equipment and/or manuals that have to be available in a turbine, including – where appropriate – by
means of adequate ventilation, detection or protection.
4.4 Floors, platforms, standing-, working places
Platforms, working places and standing places, shall be in accordance with EN ISO 14122-2,
EN ISO 14122-3 and EN ISO 14122-4.
A floor shall
– cover the horizontal cross section of the turbine tower and have no free openings wider than
0,1 m x 0,1 m without a toe plate;
– be fixed and flat;
– have an anti slip surface;
– be calculated for at least
- a concentrated load of 1,5 kN over 0,2 m x 0,2 m,
2
- an evenly distributed load of 3 kN/m with a possible maximum of 10 kN for a tower floor,
- a deflection not exceeding 1/200 of the floor span;
– be installed directly above an operating room, a low voltage or a medium voltage room;
– be installed for the step-over to the nacelle no more than 3 m below the tower top.
A platform shall have a free standing area no less than 0,5 m x 0,5 m and shall be calculated for strength
as a floor.
A standing place shall offer (if in use) the space to stand with both feet fully supported on an equal level.
A platform and a standing place shall
– offer a free space with a minimum of 2,1 m vertical headroom and 0,6 m wide above the standing area;
– be fixed and flat (partly removable or fold back permissible);

---------------------- Page: 10 ----------------------

EN 50308:2004 – 10 –
– have anti slip surface;
– be provided with a guard-rail if there is a danger of falling more than 0,5 m or be provided with grips
and anchorage points for safety harnesses if a guard-rail is necessary but not practicable for structural
reasons.
A working place can be a floor, a platform or a standing place. It shall
– offer sufficient room and body supports (steps and grips) to enter the working position;
– offer sufficient room and body support to work with the required tools and equipment without risks;
-– be at least 0,75 m deep and 2,0 m high in front of electrical cabinets equipped with switch gear.
Guard-rail/railing shall
– have a smooth rounded top rail at a height of 1,1 m minimum above the standing area;
– have a toe plate with a minimum height of 0,1 m;
– not have an unprotected gap exceeding 0,50 m between any guard rail, toe plate or intermediate rail;
– be constructed for an automatic return to a position to protect personnel after passage if access is
required through the guard rail;
– be calculated, with their supports and anchor points, for at least
- a concentrated load of 300 N/m multiplied with the maximum distance between the axes of two
successive stanchions,
- an elastic deformation with a maximum of 30 mm due to the above mentioned loads.
4.5 Climbing facilities
Climbing facilities can consist of stairways and stepladders, steps, ladders (with rest platforms), climbing
aids, grips and anchorage points. Climbing facilities shall be in accordance with EN ISO 14122-1,
EN ISO 14122-3 and EN ISO 14122-4.
Stairways and stepladders shall
– have step distances that comply with the formula: 0,6 m ≤ g + 2h ≤ 0,66 m (h is the rising-step and g is
the forward-step);
– have equal successive step distances, a deviation of 15 mm is allowed;
– have a guard-rail/handrail when there are more than two steps;
– be calculated for an average load of 3 kN/m.
A step is a climbing facility of not more than one vertical pace. It shall have a minimum width of 0,5 m and
a minimum depth of 0,2 m.
A ladder shall
– be safeguarded by an anti-fall device comprising an anchorage line and fall-protection mechanism or a
climbing cage (shaped structure) if the vertical height exceeds 3,0 m;
– have rungs with a free width of 0,4 m or more when using two uprights (0,3 m minimum is permissible
in case the environment makes the use of 0,4 m impossible);
– have rungs with a free width of 0,15 m or more when using one upright;
– have an equal successive distance between the rungs of 0,25 m and 0,30 m (a deviation of less than
15 mm is allowed);
– have rungs with a minimum diameter of at least 25 mm, the tread shall have a depth of at least 20 mm;
– have rungs fixed as to prevent sideways slipping of the foot;
– have no sharp edges on beams and rungs because they are the grip for climbing;

---------------------- Page: 11 ----------------------

– 11 – EN 50308:2004
– be calculated for a concentrated load of 1,5 kN and an average load of 1,5 kN/m;
– incorporate standing places at vertical intervals no greater than 9 m.
A foot support is a climbing facility that can consist of irons, hooks, pegs or bolts (often used as an
anchorage point for safety lines). It shall
– be safeguarded by an anchorage line and a fall-protection mechanism or a climbing cage (shaped
structure) if longer than 3,0 m,
– have a free width of 0,4 m or more, (0,3 m minimum is permissible in case the environment makes the
use of 0,4 m impossible),
– have rungs with a free width of 0,15 m or more when using staggered supports,
– have an equal successive distance between 0,25 m and 0,30 m (a deviation of less than 15 mm is
allowed),
– have a thickness or diameter with a maximum of 20 mm (based on the possible use as anchorage
point),
– have a shape that prevents sideways slipping of the foot,
– not have sharp edges because they provide a grip for climbing,
– be calculated for at least a concentrated load of 20 kN (if possibly used as an anchorage point) in any
direction without breaking down,
– incorporate standing places at vertical intervals no greater than 9 m.
A grip is a climbing aid to provide a hand hold if there is a danger of falling (often used as an anchorage
point for safety lines).
It shall
– be present on those locations where the danger of falling exists and no guard-rail can be constructed
(e.g. a step-up, a hatch-opening, a standing place, a platform, a ladder-end);
– be situated at a logical position in relation to the body and be in the right direction to provide support;
– have a maximum successive distance of 1,0 m if more than one grip is needed to ensure sufficient
body support;
– have a minimum length of 0,15 m;
– be smooth and rounded and formed to prevent the hand from slipping off;
– offer a free hand-space between the grip and any other part of the structure of 60 mm minimum.
If a grip can possibly be used as an anchorage point, see 'foot supports' for loads and dimensions.
Anchorage points for safety lines shall
– be present on those locations where the danger of falling exists and no guard-rail can be constructed
(e.g. a step-up, a hatch-opening, a standing place, a platform, a ladder-end);
– be situated at a logical position related to the body and be in the right position to provide body support
during work activities;
– have a maximum successive distance of 1,0 m if more than one anchorage point is needed;
– offer an opening having a minimum size of 30 mm diameter;
– have a cross section diameter with a maximum of 20 mm;
– have no sharp edges inside and outside;
– be calculated for at least a concentrated load of 20 kN in any direction without breaking down, because
the use of one point by two personnel is possible;
– all be coloured uniformly (yellow) to contrast with the back-ground.

---------------------- Page: 12 ----------------------

EN 50308:2004 – 12 –
Anchorage points for emergency descent equipment shall
– stand a load of 10 kN per simultaneously attached person without breaking down with a minimum of
20 kN;
– be coloured uniformly (yellow) to contrast with the back-ground and marked with the safe working load
(SWL);
– be available near the emergency access to the outside of the nacelle and marked for its use.
Fixing points for hoisting equipment shall withstand an equal or higher failure load than anchorage points
for safety lines and shall be marked with a safe working load.
Climbing facilities higher than 3,0 m shall be inaccessible for unauthorised persons.
Outside ladders require anti-climbing guards against unauthorised access. An anti-climbing guard can be
a lock out element or the removal of the lower part of the ladder (> 2,5 m).
A climb
...