I. Selection of Explosion-Proof Electrical Equipment |
1. Select the type of explosion-proof electrical equipment according to the zone classification |
|
EN60079-15 |
NEC500 |
GB3836.15 |
Zone 0 |
ia Intrinsically safe electrical equipment and circuits |
Zone 1 |
d, p, e, i, q, o, m |
Flameproof, intrinsically safe capable of withstanding 2 faults, pressurized |
d, p, e (only for junction boxes, enclosures,
single-pin fluorescent lamps, etc.)
i, q, o, m |
Zone 2 |
(1) Equipment for Zone 1
(2) "n" type
(3) Equipment that does not produce sparks during normal operation |
(1) Equipment for Zone 1
(2) "n" type
(3) Equipment that does not produce sparks during normal operation |
(1) Equipment for Zone 1
(2) "n" type |
Note 1: |
For special type equipment marked with "S", it should be selected according to the zone type indicated on the equipment, and special conditions for installation and use should be observed. |
Note 2: |
According to the actual situation in China, the "e" type equipment allowed for use in Zone 1 is limited to:
a) Junction boxes and enclosures that do not produce sparks, arcs, or dangerous temperatures during normal operation, including electrical products with a "d" or "m" type body and "e" type wiring parts.
b) "e" type low-voltage asynchronous motors (except those with frequent starting or harsh environmental conditions) equipped with appropriate thermal protection devices (GB3836.4 Appendix D).
c) Single-pin "e" type fluorescent lamps |
|
Zone 0: Places where explosive gas atmospheres occur continuously or for long periods.
Zone 1: Places where explosive gas atmospheres are likely to occur during normal operation.
Zone 2: Places where explosive gas atmospheres are not likely to occur during normal operation, and if they do occur, they will only occur infrequently and for short periods.
2. Select the type of explosion-proof electrical equipment according to the ignition temperature of the gas or vapor
Explosion-proof electrical equipment should be selected based on its maximum surface temperature not exceeding the ignition temperature of any gas or vapor that may be present.
Explosion-proof electrical equipment and ambient temperature. |
Relationship between temperature class, surface temperature, and ignition temperature |
Temperature class of electrical equipment |
Maximum surface temperature of electrical equipment |
Ignition temperature of gas or vapor |
T1 |
450℃ |
＞450℃ |
T2 |
300℃ |
＞300℃ |
T3 |
200℃ |
＞200℃ |
T4 |
135℃ |
＞135℃ |
T5 |
100℃ |
＞100℃ |
T6 |
85℃ |
＞85℃ |
|
The maximum surface temperature of electrical equipment refers to the highest surface temperature of explosion-proof electrical equipment used in explosive gas atmospheres, and this temperature must be lower than the ignition temperature of the gas or vapor present in the hazardous area. |
The ignition temperature of gas or vapor refers to the temperature at which the gas or vapor present in the explosive gas atmosphere ignites, and is a characteristic of the gas or vapor itself. |
|
3. Relationship between gas/vapor classification/grouping in the area and permitted equipment category/relationship |
Gas/vapor classification/grouping in the area |
Permitted equipment category/relationship |
ⅡA (e.g., propane, pentane, benzene, gasoline, ethanol, acetaldehyde, acetone, methylamine) |
ⅡA, ��B or ⅡC |
ⅡB (e.g., ethylene, dimethyl ether, coke oven gas, etc.) |
ⅡB, ⅡC |
ⅡC (e.g., hydrogen, acetylene, and carbon disulfide) |
ⅡC |
|
Reference standards:
GB3836.1 (equivalent to IEC60079-0): "Electrical apparatus for explosive gas atmospheres - Part 1: General requirements"
GB3836.2 (equivalent to IEC60079-1): "Electrical apparatus for explosive gas atmospheres - Part 2: Flameproof enclosure 'd'"
GB3836.3 (equivalent to IEC60079-7): "Electrical apparatus for explosive gas atmospheres - Part 3: Increased safety 'e'"
GB3836.4 (equivalent to IEC60079-11): "Electrical apparatus for explosive gas atmospheres - Part 4: Intrinsic safety 'i'"
GB3836.13 (equivalent to IEC60079-13): "Electrical apparatus for explosive gas atmospheres - Part 13: Repair and overhaul for apparatus used in explosive gas atmospheres"
GB3836.14 (equivalent to IEC60079-10): "Electrical apparatus for explosive gas atmospheres - Part 14: Classification of hazardous areas"
GB3836.15 (equivalent to IEC60079-14): "Electrical apparatus for explosive gas atmospheres - Part 15: Electrical installations in hazardous areas (other than mines)" |
II. Explosion-Proof Principles |
Explosion-proof type |
Explosion-proof principle |
Diagram |
Application examples |
Flameproof "d" |
It can withstand the explosion of a combustible mixture that has entered the enclosure without damage, and through any joint or structural opening on the enclosure, it will not ignite the external explosive atmosphere formed by the same or different gases or vapors. |
 |
Explosion-proof circuit breakers, switches, lights, starters, push buttons, control stations, distribution boxes, motors |
Increased safety "e" |
It is an electrical equipment that takes additional measures to improve its safety level for equipment that does not produce arcs or sparks under normal operating conditions, preventing dangerous temperatures, arcs, and sparks from occurring inside and on external parts. |
 |
Explosion-proof junction boxes, terminal boxes, conduit boxes, transition boxes, flexible conduits, lights, motors |
Pressurized "p" |
It is an electrical equipment that achieves safety by maintaining the pressure of the internal protective gas higher than the pressure of the surrounding explosive atmosphere. |
 |
Explosion-proof analysis houses, large motors, power distribution, instrument controllers |
Intrinsically
safe "i" |
Yangzhou DARUI Electric Co., Ltd.
Main Products: Dielectric Loss Tester, Transformer Ratio Tester, Loop Resistance Tester, HV Wireless Phase Detector, Insulation Resistance Tester, Partial Discharge Tester, Cable Fault Tester, DC Resistance Tester, etc. ☎ Tel: 18952707000 (Manager Guan)📞 Landline: 0514-88770377✉ Email: 195214804@qq.com
|
