Guidelines for anti-drop devices in rolling shutters
11 July 2006 – Page 1
DHF GUIDANCE NOTES FOR THE USE OF ANTI-DROP DEVICES
ON ROLLING SHUTTER DOORS TO COMPLY WITH BS EN 132411:2003 INDUSTRIAL, COMMERCIAL AND GARAGE DOORS AND
GATES - PRODUCT STANDARD
1
SCOPE
This guideline deals with the particular requirements that have to be met within
BS EN 13241-1:2003 in a vertical moving door when part of the suspension
system fails. It does not deal with the requirements that have to be met when
the door is in normal use.
1.1
Clause 4.28 of BS EN 13241-1 specifies as follows:
Vertically moving doors shall be safeguarded in the event of failure of a single
component in their suspension (including gear drives) or balancing system against
dropping or uncontrolled out of balance movement.
1.2
The details of these requirements are specified in EN 12604:2000 clause
4.3.4 which is reproduced in Annex C of these guidance notes. This clause
applies to all vertically moving doors whether they be manual or power
operated.
2
STATUTORY REQUIREMENTS
2.1
Power operated doors put on the UK market must, by law, meet the
requirements of:




Regulation 18 of Workplace (Health, Safety & Welfare) Regulations 1992
Document K (England and Wales), Document H (Northern Ireland) of Building
Regulations
Supply of Machinery (Safety) Regulations 2008
Construction Products Regulations 1991
It is mandatory to CE mark powered doors under the Supply of Machinery
(Safety) Regulations 1992 (Machinery Directive)
2.2
Manual doors do not need to meet the Machinery Regulations 1992 but do
have to meet Regulation 18 and Document K
2.3
CE marking under the CPR has become the only universally recognised way to
prove compliance with the essential requirements of the CPD.
2.4
Before a door may be CE marked under the CPD, the way this anti-drop
safeguard requirement is complied with must be tested and certified by a
notified body acting for the manufacturer/assembler of the door. See clause 5
for more details.
Guidelines for anti-drop devices in rolling shutters
11 July 2006 – Page 2
3
POSSIBLE SOLUTIONS – FOR ROLLING SHUTTER DOORS
3.1
Examples of ways in which the anti-drop safeguarding aspects of EN 12604
may be met with rolling shutters are given in the examples below.
3.2
Diagrams of the various examples are given in Annex A (attached) and more
information about the classification of parts that support a door is in Annex B. In
each example, the method of suspending or balancing the door is defined and
then the means of anti-drop is examined. In the notes that follow, the word
Suspension is used to encompass both Suspension or Balancing.
3.3
There are some requirements that are common to all solutions:

The anti-drop safeguard/device must be capable of being activated at any point
in a door’s travel and then prevent the closing edge of the door from dropping
more than 300 mm beyond the point at which the failure occurs.

Where the door can be expected to drop a short distance before the anti-drop
device takes hold, it is important that the design shall ensure that, if a single
failure occurs, the resulting short term transient loads imposed on other parts
of the door system will not cause secondary failures, which then cause the door
to fall.

Anti-drop safeguards do not have to be considered provided that if any one part
in the suspension system fails, the static out of balance force created at the
closing edge of the door does not exceed 200 N.

The requirements for a door in normal use laid down in supporting standards
regarding maximum stopping forces, maximum stopping distances,
uncontrolled movements, etc will always need to be complied with.
POWER OPERATED ROLLING SHUTTERS
3.4
Example 1
Rolling shutter barrel with a tubular motor and separate safety brake. No
springs fitted
The suspension system is the tubular motor, which generally comprises a brake
fitted to the motor and a planetary or similar type gearbox. The gearbox is back
driveable and, if either the brake or gearbox failed, the door would drop and must be
caught by the safety brake as an anti-drop device.
Guidelines for anti-drop devices in rolling shutters
11 July 2006 – Page 3
3.5
Example 2
Rolling shutter barrel fitted with a drive unit having an integral anti-drop
device. No springs fitted
The drive unit will normally be directly coupled to the end of the shutter barrel.
The drive unit acts as the suspension system.
In the event of a breakage in the drive system, the anti-drop device acts directly on
the barrel/shaft and will not in itself fail as a result of gearbox failure.
3.6
Example 3
Rolling shutter barrel with an external drive unit and a separate safety brake
fitted to either end of the barrel
The drive unit acts as the suspension system and, in the event of failure of any part
in it which causes the door to drop, the safety brake must automatically activate.
In this case, as the safety brake is independent of the drive unit, then the drive unit
may be connected to the barrel/shaft by roller chains, spur gears or other
mechanisms, as long as, in normal operation, the drive supports the door and allows
it to be stopped at any point in its travel.
3.7
Example 4
Rolling shutter barrel with coil springs and external drive unit
In this case, either the drive unit or the coil springs may be considered as the
suspension system and elements in either could fail. (See clause 5 for testing
requirements.)
3.7.1 Coil spring as suspension system – drive train as anti-drop device
In this case, the springs should be tensioned to balance the door. In the event that a
spring should fail, then the drive train must be capable of supporting the resulting out
of balance force of the door without failure. This shall be proven by testing (see
Annex C).
In order for this system to be properly applied, then some means of being able to
check the integrity of the spring on a regular basis will need to be considered and
noted within the maintenance manual. This aspect of regular checking is not
however a requirement at present within EN 12604.
Guidelines for anti-drop devices in rolling shutters
11 July 2006 – Page 4
3.7.2 Drive train as suspension system – coil springs as anti-drop device
The springs should be tensioned so that, in the event of the drive train failing, they
must be capable of supporting the resulting out of balance force of the door without
failure and will stop the door from falling.
3.8
Example 5
Rolling shutter barrel fitted with internal coil springs. Drive is a tubular motor
with planetary gears connected to one end of the barrel
This is really a special case of Example 4 and all the above in clause 3.7 applies .
4
MANUAL ROLLING SHUTTERS
In the three examples below, the spring is the suspension device and the system
needs to be tested against the standard in the event of failure of one spring.
4.1
Example 6
Rolling shutter barrel with multiple springs – typically two in number
In the event of one spring failing, the maximum out of balance force must not exceed
200 N. This is measured statically, although it is recognised that dynamic forces may
be greater. The out of balance force must not exceed 200 N at any position of the
door as the standard requires that consideration is given to what happens to the door
if a failure occurs at any point in the door’s travel.
4.2
Example 7
Rolling shutter barrel with coil spring suspension and a separate speed
activated brake attached to one end of the barrel
Rolling shutter may be continuous hand chain driven, or push up and down.
One consideration with this example is that it may be possible to move the shutter so
fast by hand that the brake activates. The inclusion of a hand chain keep should not
be considered as an anti-drop device.
4.3
Example 8
Rolling shutter barrel with internal coil spring and a device fitted to the coil
spring that senses spring breakage and immediately immobilises the barrel
The internal spring acts as the suspension system, and the spring break
detector/barrel immobilisation device is the anti-drop device.
Guidelines for anti-drop devices in rolling shutters
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5
SELECTION AND TESTING OF SYSTEMS
5.1
The selection of which, if any, of these solutions is used should be taken by the
manufacturer/assembler of the door depending on the exact nature of his
product and expertise.
5.2
The solutions above include comments about some features of the systems.
The comments are not exhaustive, and the manufacturer/assembler should
consider, as part of a risk assessment, all of these various aspects.
5.3
The manufacturer’s/assembler’s selected arrangement must be type tested
by a notified body. The type test can be a test in accordance with clauses 5.3.2
or 5.4.3 of EN 12605:2003, by calculation, or assessed using existing test data
on components from another notified test laboratory before the door may be CE
marked.
5.4
The manufacturer/assembler is responsible for satisfying himself that any
door he supplies which deviates from the door tested will meet the
requirements of EN 12604. He should be completely aware that such things
as door operating speed, weight, barrel size, position of door when failure
occurs and many other factors will alter the performance of anti-drop devices
and that he must be seen within his product file to have properly satisfied
these aspects before placing a CE mark on the door he supplies.
5.5
The statutory maintenance instructions for the door provided by the
manufacturer should include a test/check regime to ensure that all safety
devices, or elements of the suspension system, continue to function correctly.
With all safety critical components, the maintenance schedule should take
account of the duty cycle of the door and recommend routine replacement,
otherwise safety may be compromised.
6
RESPONSIBILITIES
6.1
It is the responsibility of the manufacturer/assembler to ensure that all antidrop safeguards or features are provided and tested in accordance within the
relevant product standards – all generally as described in the preceding
section.
6.2
It is the responsibility of the installer to check that the door has been correctly
installed in accordance with the manufacturer’s/assembler’s instructions and
works satisfactorily. He must also ensure that operating, maintenance and
servicing instructions are passed to the purchaser.
6.3
It is the responsibility of the employer/owner/occupier of the premises to
ensure that equipment is maintained and kept in good working order.
Guidelines for anti-drop devices in rolling shutters
11 July 2006 – Page 6
ANNEX A
See separate sheet
ANNEX B
Notes on the classification and design of components in a suspension or
balancing system
B1
EN 12604 states that elements of the suspension or balancing system which
could fail in operation of a door are balancing springs, steel wire ropes,
chains, straps, belts. Gear failure shall also be considered.
B2
However, if in the design of the system any of the above are duplicated so that
if one should fail, and its duplicate automatically takes on the full load without
failing, then this component is not considered as a potential point of failure.
B3
The standard also says that rigid parts, such as shafts or levers, provided that
they are dimensioned and designed for the maximum load and foreseeable
overload, need not to be considered as a potential cause of suspension
failure.
All the above should be borne in mind when considering the design of a vertical
moving door.
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11 July 2006 – Page 7
ANNEX C
C1 The full text of clause 4.3.4 within EN 12604: 2000 reads:
Vertically moving doors shall be safeguarded against dropping, or uncontrolled out of
balance movement in the event of failure of a single component in their suspension or
balancing systems. Further, the design shall ensure that if a single failure occurs, that
the resulting short term transient loads imposed on other parts of the door system will
not cause secondary failures, which then cause the door to fall.
Rigid parts, such as shafts or levers, provided that they are generously dimensioned
and designed, need not be considered as a potential cause of suspension failure.
The above requirement may be disregarded if the maximum out of balance static force
occurring at the primary closing edge of the door does not exceed 200 Newton when
there is a suspension or balancing component failure.
Safeguards against dropping can be achieved by using an anti-drop device or by other
design features incorporated into the door suspension system. These devices are all
referred to below as anti-drop safeguards and have to conform to the following:
a) If an operational brake is fitted to the drive motor of the door, this cannot be
considered on its own as the anti-drop device.
b) Door leaves shall also be safeguarded against dropping in the event of a failure in
the door suspension system when the door is switched over from power to manual
operation.
c) In the event of a failure in the door suspension system, the door leaf shall be
brought to rest after an eventual downward movement (or drop) of not more than
30 cm and held safely in this position, as long as no further action is carried out.
d) An anti-drop device, as an emergency system, shall be designed to take the full
dynamic load of the door leaf. Further, any brackets and other part of the link which
connect between the anti-drop safeguard and the door leaf shall remain effective
under the full dynamic load.
e) The anti-drop safeguard shall be automatically activated in the event of a
suspension failure.
f) Anti-drop safeguards shall be designed so that the mechanism, once activated,
cannot slip as a result of vibrations, oscillations etc. Suitable warnings shall be
given, to instruct users to seek trained help to release any such device which has
activated.
g) An anti-drop safeguard or other door components may incorporate parts which
shall be replaced once the safety device has been in operation. The existence and
extent of such parts shall be specified by the manufacturer. Where replacement
parts are not specified the activations of the anti-drop safeguard shall not cause
deformation which impairs the subsequent operation.
Guidelines for anti-drop devices in rolling shutters
11 July 2006 – Page 8
NOTE 1:
Examples of elements of the suspension system which could fail are steel wire ropes,
chains, straps, belts, gears.
NOTE 2:
Examples of methods of safeguarding by "Other Design Features" are described in
Annex B (informative.)”