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Sufficient consideration is given to the safety and reliability, since it is used in a site using an explosive gas. The Hitachi explosion-proof hoist / crane saddle is designed for operation in a chemical or coating plant using explosive gas. The explosion-proof ability of the hoist / crane saddle is applicable to a range of gas up to Ignition group G4 and Explosion class 2. (Refer to the Table of Explosion and Ignition ratings for Explosive Gasses.)
Hitachi explosion-proof hoist is designed so that it corresponds to the following regulation categories of Japanese Ministry of Labor.
|Ignition Group||G1 to G4|
|Explosion Proof||1 and 2|
|Division of Hazardous Locations||2|
In order to operate the explosion-proof safely even in the places with an explosive gas, reasonable maintenances should be taken place as the explosion-proof construction must be kept effectively. Also, any building in which the explosion-proof hoist is installed should be equipped with a ventilation system so that the explosive gas is eliminated effectively.
The standard ambient conditions for the explosion-proof electrical equipment is as follows:
The "– XX" in the types show the explosion-proof.
Explosive gases are classified according to their ignition rating and explosive rating depending on the degree of danger.
Ignition groups are classified as follows according to the ignition points of the individual gases. The Hitachi explosion-proof hoist can be used for gases of up to G4 for ignition groups or up to 135°C for ignition point.
|Ignition Group||Ignition Point|
|G2||Over 300°C to 450°C|
|G3||Over 200°C to 300°C|
|G4||Over 135°C to 200°C|
|G5||Over 100°C to 135°C|
|G6||Over 85°C to 100°C|
Explosion class is classified into the following depending on the value of the gap through witch the ignition spreads.
|Explosion Class||The value of the gap through which the ignition spreads with 25mm in depth.|
|1||Over 0.6 mm|
|2||Over 0.4 mm to 0.6mm|
|3||0.4 mm and below|
Typical explosive gases classified by the ignition and the explosion ratings are as follows:
|Acetylene||Carbon disulfide||Ethyl nitrate|
Bold text Hitachi explosion-proof hoist can be operated.
The upper limit rise of temperature of electrical equipment in an explosive gas is as follows when the ambient temperature is 40°C.
|Upper Limit of Temperature rise||320||200||120||70||40||30|