T000-00001-EN - 2 - 1
Enquiry form - ATEX operating conditionsCustomer data
Company
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Specifications
Drive
Power takeoff (PTO)
Output
Operating speed
Rated torque
Type of application Operating temperature
Please enter the required protection class here:
c
1: ATEX sign 2: Device group 3: Category 4: Ignition protection type 5: Explosion group 6: Temperature class
Example:
II 2G c IIB T61: ATEX sign 2: Device group 3: Category 4: Ignition protection
type 5: Explosion group 6: Temperature class
The following pages contain information on determining the required protection class!
Explanations ATEX operating conditions
Determining the device group
Device Group I:
Equipment used in underground mines and their above-ground facilities.
Subgroup M1: Subgroup M2:Very high level of safety:It must be possible to operate the devices in the presence of an explosive atmosphere.CENTA couplings cannot be dimensioned for the Device Group M1.
High level of safety:These devices may be switched off when an explosive atmosphere develops.
Device Group II:
Equipment used in other areas that may be endangered by an explosive atmosphere.
Subgroup D: Subgroup G:Devices for areas where dust can form explosive atmospheres.
Devices for areas in which explosive gas, vapour, mist, and air mixtures exist.
By default, CENTA couplings fall under Device Groups I (M2) or II (D/G).
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Explanations ATEX operating conditions
Determine categoryStep 1: Division in zones Initially, potentially explosive areas must be divided into zones according to the frequency and duration of the occurrence of hazardous explosive atmospheres: Potentially explosive atmosphere by
Zone In normal operation, the explosive atmosphere exists ...
Comment
Gases,vapours,mists
0 ... constantly and over long periods of time or frequently.
CENTA couplings cannot be used
1 ... occasionally.2 ... rarely and briefly.
Dusts 20 ... constantly and over long periods of time or frequently.
CENTA couplings cannot be used
21 ... occasionally.22 ... rarely and briefly.
Step 2: Determining the device categoryNext, ensure the devices and equipment to be used may be used in the respective zone.
The device category indicates in which zone a device may be used. The device subcategories “D” and “G” (see above) have been further subdivided for this purpose:Device category
Explosion hazard from
Can be used in zone(s)
The potentially explosive atmosphere exists
Level of safety
Comment
1D Dust 0, 1, 2... constantly and over long periods of time or frequently.
very high not possible
2D Dust 1, 2 ... occasionally. high
3D Dust 2 ... rarely and briefly. normalonly non-conductive dust
1G Gas 20, 21, 22... constantly and over long periods of time or frequently.
very high not possible
2G Gas 21, 22 ... occasionally. high3G Gas 22 ... rarely and briefly. normalM1 Mining -- very high not
possibleM2 Mining -- high
CENTA couplings may only be used in Zones 1 and 21 as well as 2 and 22 and thus comply with the device categories 2D / 3D (3D only for non-conductive dust, 2D includes 3D), 2G / 3G (2G includes 3G) and M2.
Specified type of protection “Constructive Safety (c)”Page 3 of 5
Explanations ATEX operating conditions
Type of protection = the manner in which ignition sources are preventedCENTA couplings are supplied exclusively with the type of protection “Constructive Safety (c)”.
Determining the explosion groupGases: European Explosion Groups IIA, IIB and IICVarious explosive atmospheres are subdivided into different explosion groups depending on their ignitability and their ability to spark ignitions. The dangerous nature of gases increases from Explosion Group IIA to IIC!
Typical gases Formula
Minimum ignition energy [mJ]
Explosion group
Methane CH4 0.280 IIAPropane C3H8 0.250 IIA
Ethylene (ethene) C2H4 0.082 IIBHydrogen H2 0.016 IIC
Acetylene (ethyne) C2H2 0.019 IICCarbon disulfide CS2 0.009 IIC
Dust: no explosion groups, specify minimum ignition energy!
Mining: Not grouped, provided only methane exists in combination with pulverized coal. The gas groups apply if another gas exists.
By default, CENTA couplings are approved for IIA and IIB. They are also approved for IIC provided the explosive environment consists of mixed hydrogen gases. Other environments on request and after verifying the environment’s compatibility for the elastic element used. Carbon disulphide environments are not possible.IIC includes IIB. IIB includes IIA.
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Explanations ATEX operating conditions
Determining the temperature class
Devices and equipment may only be operated in an explosive atmosphere if their maximum surface temperature remains below the ignition temperature of the explosive mixture!
The ignition temperature of a gas or fluid is the lowest temperature of a heated surface at which the ignition still occurs.
Temperature classPermissible surface temperature [°C]
Ignition temperature range of the combustible substances
[C]T1 450 >450T2 300 300 - 450T3 200 200 - 300T4 135 135 - 200T5 100 100 - 135T6 85 85 - 100
CENTA couplings may be used in the various temperature ranges as follows:T1/T2/T3 -40 °C to +80 °C ambient temperatureT4: -40 °C to +78 °C ambient temperatureT5: -40 °C to +50 °C ambient temperatureT6: -40 °C to +38 °C ambient temperature
Exceptions:CENTAFLEX-A: T5 to 59 °C; T6 to 47 °CRubber elements: T5 to 43 °C; T6 to 31 °C
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