Safety Q&A: Division of Explosion Proof Levels

First, the protection level is not lower than IP55, the explosion-proof level is ExdIIBT4

Q: The protection level is not lower than IP55 and the explosion-proof level is ExdIIBT4 . What does this mean?

In addition, there is a saying that “ explosion-proof grade 2 ” . According to what standard the secondary explosion protection is based on, is it achieved that the protection level is not lower than IP55 and the explosion-proof level is ExdIIBT4 ?

A: IP protection class is composed of two figures, the first digit represents the dust from the lamp, preventing intrusion of foreign material level, and the second number represents the lamp against moisture, water penetrated closed level, higher numbers mean that protection The higher the level.

The first 5 of IP55 means that dust prevention completely prevents the intrusion of foreign objects. Although the dust cannot be completely prevented from entering, the amount of intruded dust does not affect the normal operation of the lamp.

The second 5 represents the prevention of the intrusion of sprayed water to prevent water injected from the nozzle in each direction from entering the luminaire to cause damage.

Explosion-proof generic terms EX , d stands for explosion-proof, (First, there are several places to note this: d represents the explosion, de represents the main explosion-proof secondary safety, ed represents the main increase security explosion, e represents increased security, the logo is different The practice is different.) IIB explosion-proof grade (generally IIB, IIC more, intrinsically safe ia ) T4 temperature level ( T1\T2\T3\T4\T5\T6 ) T4 represents 135 degrees.

Explosion-proof grade II is the meaning of the above class II

Second, explosion-proof level instructions

Ia Ratings — Under normal operating conditions and when there is a fault or two faults in the circuit, the explosive gas mixture cannot be ignited. In the ia type circuit, the operating current is limited to 100mA or less.

1. Q: What is the increased safety ( e -type) meter?

A: Under normal operating conditions, sparks or dangerous temperatures that ignite the explosive mixture will not be generated, and measures (such as sealing) will be taken to improve the safety of the explosive mixture to avoid ignition under normal and specified overload conditions. equipment.

2. Q: How is China's division of explosive hazardous locations?

A: The division of explosive hazardous locations in China uses an equivalent method to IEC . The national standard GB 50058-92 stipulates that explosive gas dangerous places are divided into three levels of Zone 0, Zone 1, and Zone 2 according to the degree of danger. Explosive dust hazardous sites are divided into two levels, Zone 0 and Zone 11 .

3. Q: How is the international classification of explosive hazardous locations?

A: The division of explosive hazardous locations in major international industrial countries can basically be divided into two opinions.

A representative of the IEC (International Electrotechnical Commission), including Germany, Britain, Italy, Japan, Australia and other countries, the gas is divided into 0 zones, 1 zone, 2 zones, dust is divided into 10 zones, 11 zones. Its definition is basically the same as that of IEC (see definition of each region in China, equivalent IEC standard in China).