appendixD
(Normative)
AsExExplosion proof enclosure for components
D.1General Provisions
Issuance of empty shellExThe purpose of the component explosion-proof certificate is to enable the manufacturer of the explosion-proof enclosure to obtain an explosion-proof certificate when the internal installation is uncertain, so that third parties can use this enclosure to obtain complete equipmentExplosion proof certificateThere is no need to repeat all of this document andGB/T 3836.1Required explosion-proof shell type test. When a complete equipment explosion-proof certificate is required, it is not necessary to obtain an empty shellExExplosion proof certificate for components.
D.2introduction
This appendix contains information on the explosion-proof enclosure for airExComponent casingExplosion proof certificateThe requirements. This does not cancel the subsequent equipment explosion-proof certificate, but it makes it easier to obtain the equipment explosion-proof certificate.
The holder of the Ex component enclosure explosion-proof certificate shall ensure that:
a) Structure andExThe original design specified in the documents mentioned in the explosion-proof certificate of the component casing is consistent;
b) Conduct the necessary factory overvoltage test; and
c) SatisfyExThe limiting conditions specified in the explosion-proof certificate of the component casing.
D.3 ExRequirements for component casing
D. When applicable,ExThe component casing should meet the requirementsGB/T 38:36.1According to the requirements of this document.
D. 3.2 The outer shell of Ex components is generally square, rectangular, or has a cross-sectional taper not exceeding10%The simple geometric shape of a cylindrical shape.
Note: Simple geometric shapes are considered to include these structures: the ratio between major dimensions and any other major dimensions, Class I ⅡAClass and IIBClass not exceeding4：1, and IICClass not exceeding2：1.
D. 3.3 The casing of a rotating motor should not be used asExEvaluate the component casing.
Note: "Motor" refers to an electric motor whose casing is fully filled.
D. 3.4 The outer shell of Ex components should have appropriate measures and sufficient positions to install internal components.
D. 3.5 should not be includedExDrill holes on the component casing, whether for mechanical or electrical purposes, blind or through holes,ExUnless otherwise specified in the explosion-proof certificate of the component casing.
D. 3.6 For Class I ⅡAClass and IIBclassExThe reference pressure for the component casing should be based on15.2.2The prescribed measurement. The sample for the experiment needs to be modified according to the following requirements:
——When the proportion of main dimensions does not exceed2 : lThere is no need to modify the sample at this time;
For all other permitted structures, additional partitions need to be placed inside the casing, with an area approximately equal to the cross-sectional area of the casing80%,The partition should be placed on the main axis2/3At and parallel to the secondary axis. The partition should appropriately reproduce the cross-section of the shell.
aboutll CclassExThe reference pressure for the component casing should be based on15.2.2According to the regulations, a partition is placed inside the shell, and the area of the partition is approximately equal to the cross-sectional area of the shell60%The partition should be placed on the main axis2/3At and parallel to the secondary axis. The partition should appropriately reproduce the cross-section of the shell.
When a partition is needed to process the sample, the ignition source and pressure recording device should be placed on both sides of the partition while measuring the pressure.
D. 3.7 onExThe number of openings for the sample subjected to overvoltage type testing on the component casing should be the maximum allowable number of openings. The size of the hole should also be the maximum allowable size, and the test pressure is 1.5 Multiple times the reference pressure, the reference pressure is based on15.2.2The regulations areExMeasure on the empty shell of the component. All inlet ports are sealed with appropriate methods.
If4If the static pressure at times the reference pressure has undergone the prescribed type test, there is no need for routine testing. But the shell of the welded structure should undergo routine tests in any case.
Routine tests should be conducted using one of the following methods:ExInternal and external use of component casing15.2.2(The explosive mixture specified for measuring explosive pressure1.5Conduct explosion tests at atmospheric pressure, or use at least350kPaConduct a static pressure test at a pressure of, but not less than1.5 Double the reference pressure.
D. 3.8 The shell should be designed according toGB/T3836.1ofExComponent labeling is required, but it should be internal and not necessarily permanent.ExThe flag string should not be marked externally. Only the manufacturer's name and housing identification information (such as model or serial number) can be marked on the outside of the housing. This symbol does not need to be permanent.
IfExIf the manufacturer of the component casing is also the holder of the explosion-proof certificate for the entire equipment, this mark can be omitted and should be included inExThis is stated in the restriction conditions of the explosion-proof certificate for components.
D. 3.9 The requirements for setting external signs of equipment should comply withGB/T 3836.1The regulations.
D. 3.10 inExThe explosion-proof certificate of the component casing should provide the following restrictions:
——The maximum number, maximum size, and location of holes should be directly stated or referenced to the drawing.
——Oil filled circuit breakers and contactors should not be used.
——(Exceeding)-20°C~ 40°CExternal environmental temperature range
——(If pressed)D 3.8Applicable) indicatesExThe component casing manufacturer will be the relevant equipmentExplosion proof certificateThe sole holder.
——For Class I and IIAClass and IIBclassExAs long as there are at least20%The area can allow unobstructed gas flow, unrestricted explosion diffusion, and the internal components can be arranged freely. If each region has at least12.5 mmIf the space is long, these individual release areas can be merged and calculated.
——- (For)llCclassExAs long as there are at least40%The area can allow unobstructed gas flow, unrestricted explosion diffusion, and the internal components can be arranged freely. If each region has at least12.5mmIf the space is long, these individual release areas can be merged and calculated.
——Additional limitations for special structural requirements, such as the maximum operating temperature of the observation window.
D.4utilizeExApplication for Component Shell Certificate and Equipment Explosion proof Certificate
D. 4.1 Program
ObtainedExElectrical equipment enclosures with explosion-proof certification for component enclosures, if they comply withD.3.10The requirements specified in the regulations can be considered for incorporation into complianceGBT 3836.1The explosion-proof certificate of the equipment in this document usually does not need to be repeated as it already complies with the requirementsExRequirements for component casing.
The equipment that is allowed to be replaced or omitted according to regulations, as well as the installation conditions inside the casing, should be explained in the prepared documents to verify complianceExThe limiting conditions in the explosion-proof certificate of the component casing.
stayExComponent casingExplosion proof certificateThe holes allowed in the middle can beExProvided by the component casing manufacturer, or through the equipment manufacturer andExThe negotiation between component casing manufacturers shall be provided by the equipment manufacturer.
Continuous effects of the device should be considered, such as rotating devices, which may cause significant turbulence leading to an increase in reference pressure.
D. 4.2 Restrictions on Use Conditions
In addition to meeting the restrictions, all usage scenarios should be considered and determined to comply with themGB/T:3836.1Related provisions of this document
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