Shenhai e fakamoʻoni fakaʻauha
Ko e fakaʻilonga ʻo e fakamoʻoni fakaʻauha ʻi he maama ʻo e fakaʻauha hono naunau ko ha fakaʻilonga ia ʻoku ne fakamatalaʻi ʻa e maaka ʻo e fakamoʻoni fakaʻauha, kulupu mafana, taipeʻi, mo e ngaahi feituʻu ʻoku fekauʻaki mo e naunau ʻo e mama.
Fakamatala ki hono fakaʻilongaʻi ʻo e fakamoʻoni fakaʻauha:
Hange ko e GB 3836 ngaahi tuʻunga moʻuí, ʻOku kau ʻi hono fakaʻilongaʻi ʻo e mama hono naunau ʻa e:
Faʻahinga ʻo e fakamoʻoni fakaʻauha + Faʻahinga Meʻangāué + (Kulupu kasa) + Kulupu mafana.
1. Faʻahinga ʻo e fakamoʻoni fakaʻauha:
Tepile 1 Basic Types of Explosion-Proof
| Explosion proof form | Explosion proof form sign | Explosion proof form | Explosion proof form sign |
|---|---|---|---|
| Faʻahinga Flameproof | EX d | Sand filled type | EX q |
| Fakalahi e faʻahinga malu | EX e | Encapsulation | EX m |
| Barotropic type | EX p | N-Type | EX n |
| Intrinsically faʻahinga malu | EX ia EX i | Special type | EX s |
| Faʻahinga ʻohofi ʻo e lolo | EX o | Dust explosion-proof type | EX A EX B |
2. Faʻahinga Meʻangāué:
Electrical equipment for fakafepakiʻi gas atmospheres is divided into:
Kalasi ʻoku ou: For use in coal mines;
Kalasi II: For use in explosive gas atmospheres other than coal mines.
Class II explosion-proof “d” mo e malu ʻoku ʻikai ke malu “i” electrical equipment are further divided into IIA, IIB, and IIC classes.
Electrical equipment for combustible efu environments is divided into:
Type A dust-tight equipment; Type B dust-tight equipment;
Type A dust-proof equipment; Type B dust-proof equipment.
3. Fakamatala ki hono fakaʻilongaʻi ʻo e fakamoʻoni fakaʻauha:
The ability of an explosive gas mixture to propagate an explosion indicates its level of explosion hazard. The greater the ability to propagate an explosion, the higher the danger. This ability can be represented by the maximum experimental safe gap. ʻIkai ngata ai, the ease with which explosive gases, ʻahu, or mists can be Maʻuʻanga Fakamatala also indicates the level of explosion hazard, represented by the minimum igniting current ratio. Class II explosion-proof or intrinsic safety electrical equipment is further classified into IIA, IIB, and IIC based on their applicable maximum experimental safe gap or minimum igniting current ratio.
Tepile 2 Relationship between the Group of Explosive Gas Mixtures and the Maximum Experimental Safe Gap or Minimum Igniting Current Ratio
| Kulupu kasa | Sivi lahi taha ʻo e malu MESG (m m) | Siʻisiʻi taha ignition e fika MICR |
|---|---|---|
| IIA | MESG≥0.9 | MICR>0.8 |
| IIB | 0.9＞MESG≥0.5 | 0.8≥MICR≥0.45 |
| IIC | 0.5≥MESG | 0.45>MAʻU |
4. Kulupu mafana:
Ko e ignition mafana ʻo e ʻea of an explosive gas mixture is the limit temperature at which it can be ignited.
Electrical equipment is classified into T1 to T6 groups based on their highest surface temperature, ensuring that the maximum surface temperature of the equipment does not exceed the permissible value of the corresponding temperature group. The relationship between temperature groups, equipment surface temperature, and the ignition temperature of velangofua gases or vapors is shown in Table 3.
Tepile 3 Relationship between Temperature Groups, Equipment Surface Temperature, and Ignition Temperature of Flammable Gases or Vapors
| Levolo ʻo e ʻea IEC/EN/GB 3836 | Ko e mafana maʻolunga taha ʻo e meʻangaue T [° C] | Lgnition e mafana ʻo e ngaahi meʻa combustible [° C] |
|---|---|---|
| T1 | 450 | T>450 |
| T2 | 300 | 450≥T>300 |
| T3 | 200 | 300≥T>200 |
| T4 | 135 | 200≥T>135 |
| T5 | 100 | 135≥T>100 |
| T6 | 85 | 100≥T>8 |
5. Requirements for Setting Markings:
(1) Markings should be prominently placed on the main body of the electrical equipment;
(2) The markings must remain clear and durable under potential chemical corrosion. Markings such as Ex, faʻahinga ʻo e fakamoʻoni fakaʻauha, faʻahinga, and temperature group can be embossed or debossed on the visible parts of the casing. The material for the marking plate should be chemically resistant, such as bronze, palasa, pe stainless ukamea.