BS/EN 16770-2018 pdf download.Safety of woodworking machines – Chip and dust extraction systems for indoor installation – Safety requirements.
5.6 Protection against hazardous substances
5.6.1 Dust emissions
Extraction systems shall be designed and constructed to avoid leakage.
The filter elements within the dust extractor shall be protected against mechanical damages caused by external impact or by aspirated particles.
NOTE Baffle plates, pre-separators or effective gravity separation are adequate measures.
It shall be possible to remove and empty the bins with a minimum of dust-release, e.g. by usage of bin liners. The maximum usable volume of the bin shall be Indicated with a mark and the filling level shall be visible without removal of bin or liner.
Bin liners shall be protected against aspiration by the fan within the dust extractor, e.g. by pressure compensation ducting. If a pressure compensation duct is connected to the clean air part of the dust extractor, dust pollution shall be avoided, e.g. by a filter element Installed inside the pressure compensation duct that is at least of the same air filter class as the main filter elements.
When recirculation air Is used (depending on national regulation), the residual dust content In the recirculation air shall not exceed 0,1 mg rn-3.
Verification: By visual inspection of the extraction system, measurement of the residual dust content in the recirculation air according to Annex E, or by checking of the measurement reports. It is possible to use measurement reports from comparable dust extractors (i.e. same type of fIlters, same material of filter elements, same cleaning system, similar filtering ratio, similar filter pressure drop during operation).
5.6.2 Performance requirements
The design and construction of the extraction system shall enable all connected woodworking machines operating tinder the specified working conditions to have as a minimum the Indicated volume flow rate.
For the effective extraction of woodworking machines, the vacuum shall be at least 2 000 Pa at an average air velocity of 22 ms’ (10 % above nominal volume flow rate) at the inlet of the dust extractor and the minimum runtime before filter cleaning shall be at least 15 mm. The air velocity at the inlet shall not drop below 18 ms- during runtime (not more than 10 % below nominal volume flow rate). The dust extractor shall be able to run permanently in order to prevent thermal stress of the fan drive with an undcrprcssure of 500 Pa maximum at the extraction connection point.
Gate valves for disconnecting a single woodworking machine or other extraction connection points shall operate automatically in order to ensure the minimum required volume flow rate for material transport. As an exception manual gate valves may be used for disconnection of single woodworking machines with a volume flow rate less than 10 % of the total volume flow rate.
All dust extractors shall be equipped with cleaning devices for filter media. Dust extractors with a volume of the dust loaded part above 0,8 m3 shall be equipped with automatic cleaning devices and with an interface for an external start/stop signal that starts and stops the dust extractor automatically.
Verification: By checking the relevant drawings and by measurements according to Annex E. 5.6.3 Performance indication
The extraction system shall he fitted with equipment for the permanent monitoring of the volume flow rate. The monitoring can be ensured for example by the following measures:
— underpressure monitoring at the main duct;
— pressure difference measurement over the filter elements.
The monitoring system shall indicate by audible and/or visual alarm when the performance is out of range (i.e. pressure drop higher than calculated value, volume flow rate below minimum).
Verification: By visual inspection, measurement of the air velocity in the ducts and checking of the measurement reports at hand.
5.7 ProtectIon against electrical hazards
With the exception of 6.3, the requirements of EN 60204-1:2006 and EN 60204-1:2006/A1:2009 apply unless stated otherwise in this document.
See EN 60204-1:2006 and EN 60204-1:2006/A1:2009, 6.2 for the requirements regarding prevention of electric shock due to direct contact, and EN 60204-1:2006 and EN 60204-1:2006/A1:2009, Clause 7 for the requirements regarding protection against short circuits (feeder circuit excluded) and overloading.
The machine manufacturer shall provide the protective bonding system of the machine up to protective earth terminal and shall give information to the user on how to complete protection against electric shock due to indirect contact (see information provided by the manufacturer in the instruction handbook 6.3.2 j)).
The machine manufacturer shall provide to the user information on how to provide the protection against short circuits of the feeder circuit (see information provided by the manufacturer in the instruction handbook, 6.3.2 k)).
NOTE I Protection against short circuits of the feeder circuit is not up to the machine manufacturer.BS/EN 16770-2018 pdf download.