Selection of Equipment & Type of Ex Protection for Dust - - PowerPoint PPT Presentation
Selection of Equipment & Type of Ex Protection for Dust locations. Aug. 2010 Mike Scott : EXB Electric (Pty) Ltd. www.exbelectric.co.za Tel. + 27 11 887 8941 Fax. + 27 11 887 8945 Thank You Peter Turnherr , CEO of thuba and a member of
Selection of Equipment & Type of Ex Protection for Dust locations. Aug. 2010
Mike Scott : EXB Electric (Pty) Ltd.
www.exbelectric.co.za
EXB Electric (Pty) Ltd.
Thank You
member of numerous working groups and committees (IEC) associated with Explosion Protection. Peter has made available a lot of information and material used in this presentation. The thuba group of companies are mainly concerned with various aspects of Explosion Protection.
EXB Electric (Pty) Ltd.
Disclaimer All information in this presentation is given in good faith and does NOT replace standards, codes of practice and any other requirements of industry or
EXB Electric (Pty) Ltd and / or the writer / presenter will / are NOT responsible for any errors / miss- understandings.
EXB Electric (Pty) Ltd.
IEC 60079-14
International Standards
IEC 60079-17 IEC 60079-19
EXB Electric (Pty) Ltd.
Qualifications of personnel The design of the installation, the selection of equipment and the erection covered by this standard shall be carried out only by persons whose training has included instruction on the various types of protection and installation practices, relevant rules and regulations and
The competency of the person shall be relevant to the type of work to be undertaken.
EXB Electric (Pty) Ltd.
Information required
the equipment protection level requirements where applicable
to the subgroup of the electrical equipment
EXB Electric (Pty) Ltd.
Information required
combustible dust cloud, minimum ignition temperature of the combustible dust layer and minimum ignition energy of the combustible dust cloud
EXB Electric (Pty) Ltd.
General requirements Hazardous areas are classified into Zones 20, 21 and 22 for combustible dusts according to IEC 60079-10-2 in order to facilitate the selection
EXB Electric (Pty) Ltd.
General requirements Electrical installations in hazardous areas shall also comply with the appropriate requirements for installations in non-hazardous areas.
SANS 10142 in RSA
However the requirements for non-hazardous areas are insufficient for installations in hazardous areas.
SANS 10086 in RSA
EXB Electric (Pty) Ltd.
General requirements Equipment shall be installed in accordance with its documentation.
EXB Electric (Pty) Ltd.
General requirements Installations should be designed and equipment and materials installed with a view to providing ease of access for inspection and maintenance (IEC 60079-17).
EXB Electric (Pty) Ltd.
Selection of repaired, second hand
When it is intended that existing, second hand or repaired equipment is to be installed in a new installation, it shall only be reused if: a) it can be verified that the equipment is unmodified and is in a condition that meets the content of the original certificate (including any repair or overhaul) b) any changes to equipment standards relevant to the item considered do not require additional safety precautions.
EXB Electric (Pty) Ltd. Use of equipment that is not certified
simple electrical apparatus used within an intrinsically safe circuit. (The I S loop needs certification)
EXB Electric (Pty) Ltd.
Equipment Protection Level (EPL)
20 Equipment Protection Level (EPL) Zone 22 21 Dc, Db and Da Db and Da Da
EXB Electric (Pty) Ltd. Comparison of Dust Zones and Gas Zones.
Dust (Zone 20) ~ Gas (Zone 0) Dust (Zone 21) ~ Gas (Zone 1) Dust (Zone 22) ~ Gas (Zone 2) (NB: approximately)
EXB Electric (Pty) Ltd.
Type of protection and EPL
Type of protection
Da
General requirements Protection by enclosure
EPL
IEC 60079-31 IEC 60079-0
Standard
iaD ta
Code
IEC 61241-11 Protection by intrinsic safety Protection by encapsulation ma IEC 60079-18
EXB Electric (Pty) Ltd.
Type of protection and EPL
Type of protection
Db
Protection by enclosure Type of protection „pD“ Protection by encapsulation
EPL
IEC 61241-11 IEC 60079-31
Standard
pD mb ibD
Code
tb IEC 61241-4 IEC 60079-18 Protection by intrinsic safety
EXB Electric (Pty) Ltd.
Type of protection and EPL
Type of protection
Dc
Protection by enclosure
EPL
IEC 60079-31 IEC 61241-4
Standard
mc tc
Code
pD IEC 60079-18 Protection by encapsulation Type of protection „pD“
EXB Electric (Pty) Ltd. Suitability of apparatus for less hazardous locations.
DUST Hazardous Locations EPL level Da : Suitable for Zones 20 & 21 & 22 EPL level Db : Suitable for Zones 21 & 22 EPL level Dc : Suitable for Zone 22 ONLY GAS Hazardous Locations EPL level Ga : Suitable for Zones 0 & 1 & 2 EPL level Gb : Suitable for Zones 1 & 2 EPL level Gc : Suitable for Zone 2 ONLY
EXB Electric (Pty) Ltd.
Group III (Dust)
IIIA Equipment groups (dust) IIIC IIIB Conductive dust Non-conductive dust Fibres
EXB Electric (Pty) Ltd. Comparison of Equipment Groups.
Group I : Fiery Mines, (Firedamp (Methane / Coal Dust)) Group II : Industries other than mines. (surface industries) Group II A : Propane for Example Group II B : Ethylene for Example Group II C : Hydrogen gas for Example Group III : Dusts. Group III A : Fibres. Polyester / cotton for example Group III B : Non Conductive dust. Grain for example Group III C : Conductive dust. Aluminum for example
EXB Electric (Pty) Ltd.
Dust clouds Temperature limitations because of the presence
The maximum surface temperature of the apparatus shall not exceed two-thirds of the minimum ignition temperature in degrees Celsius
(C) of the dust/air mixture concerned:
Tmax ≤ ⅔ TCL
where TCL is the minimum ignition temperature of the cloud of dust
EXB Electric (Pty) Ltd.
Dust layers
– up to 5 mm thickness – above 5 mm up to 50 mm – dust layers above 50 mm
EXB Electric (Pty) Ltd.
EXB Electric (Pty) Ltd.
Dust layers
EXB Electric (Pty) Ltd.
Plugs and socket outlets for dust
not enter the socket outlet with or without a plug in place.
dust cap being accidentally left off, socket outlets shall be positioned at an angle, which is not more than 60 degrees to the vertical, and the opening facing downwards.
EXB Electric (Pty) Ltd.
Plugs and socket outlets for dust
≤ 60°
EXB Electric (Pty) Ltd.
External factors
EXB Electric (Pty) Ltd.
Equipment shall normally be designed for use in an ambient temperature range between –20 ºC and 40 ºC; in this case, no additional ambient temperature marking is required. Example of extended ambient temperature range Tamb Tamb –30C to 65C. Ambient temperature
EXB Electric (Pty) Ltd.
Ambient temperature
EXB Electric (Pty) Ltd.
Ambient temperature
EXB Electric (Pty) Ltd.
EN 60079 – 0 : 2009 - 08 General Requirements
IEC 61241-2-1
Methods for determining the minimum ignition temperatures of dust
IEC 61241-2-2
Method for determining the electrical resistivity of dust in layers
IEC 61241-20-3
Method for determining minimum ignition energy of dust/air mixtures
EN 60079-31:2008
Protection by Enclosure «t»
EN 61241- 4:2006
Protection by Pressurization «pD»
EN 61241-11:2006
Intrinsic Safety «iD»
EN 60079-18:2008
Protection by Encapsulation «m»
EN 60079-10-2:2009
Area classification
EN 60079-14:2009
Electrical installation design, selection and erection
EN 60079-17:2007
Inspection and maintenance
EN 60079-19:2007
Repair and Overhaul
Standards for dust
Protection by Enclosure «t»
EXB Electric (Pty) Ltd.
Group III
IIIA Equipment groups (dust) IIIC IIIB conductive dust non-conductive dust fibres
EXB Electric (Pty) Ltd.
36
2.
Aging resistance testing (thermal endurance)
Hot and cold storage tests
3.
Testing for mechanical strength
Impact test
4.
Testing for dust protection
Ingress test in dust test chamber
5.
Electrostatics
Take appropriate measures
1.
Limiting surface temperature
Thermal tests
Protection by enclosure «t»
EXB Electric (Pty) Ltd.
Protection by enclosure «t» Sequence of tests Testing for aging resistance Testing for mechanical strength Testing for dust protection Evaluation of dust protection taking into consideration aging and mechanical influences
EXB Electric (Pty) Ltd.
Protection by enclosure «t» Dust ingress protection IP 6X
Equipment for Zones 20 and 21 Equipment for Zone 22 with conductive dust
Dust ingress protection IP 5X
Equipment for Zone 22 with non-conductive
dust
EXB Electric (Pty) Ltd.
Protection by enclosure «t»
Intrinsic Safety «iD»
EXB Electric (Pty) Ltd.
Intrinsic safety «iD»
(equipment parameters, including conductor length)
EXB Electric (Pty) Ltd.
Marking
RAL 5012
EXB Electric (Pty) Ltd.
Simple apparatus
(exception: thermocouples, photocells, etc.,) limited to 1.5 V, 100 mA and 25 mW
EXB Electric (Pty) Ltd.
Simple apparatus
against spark ignition is afforded primarily by the source – the «associated apparatus».
certified.
EXB Electric (Pty) Ltd.
Marking simple apparatus
No ATEX mark may be applied to the apparatus!
EXB Electric (Pty) Ltd.
Associated apparatus
(observe the interconnection parameters!)
EXB Electric (Pty) Ltd.
Associated apparatus
NOTE the square brackets used in the marking.
EXB Electric (Pty) Ltd.
Associated apparatus
EXB Electric (Pty) Ltd. Hazardous area
Switching contact
e.g. pressure switch, thermostat
Mains
Non-hazardous area
Output
Associated apparatus
Pressurized enclosure «p»
EXB Electric (Pty) Ltd.
EXB Electric (Pty) Ltd.
Pressurized enclosure «pD»
Explosion Protected. (Standard Ignition Capable components)
Minimum requirement 0.5 mbar (power switched off at ≤ 0.8 mbar if a leak occurs)
(max. rating 1.5 V, 100 mA, 25 mW)
EXB Electric (Pty) Ltd.
EXB Electric (Pty) Ltd.
thuba Blue [is]
Ex tD [ibD] [pD] A21 IP65 T70°C Ex e mb [ib] [px] IIC T4
EXB Electric (Pty) Ltd.
Thank you for your attentiveness. Thank you to SAF