1. 隔爆型电气设备
具有能承受内部爆炸性气体混合物的爆炸压力，并阻止内部的爆炸向外壳周围爆炸性混合物传播的外壳电气设备，标志为“d”。
2. 增安型电气设备
在正常运行条件下不会产生电弧、火花或可能点燃爆炸性混合物的高温，结构上采取措施提高安全裕度，以避免在正常和认可的过
载条件下出现电弧、火花或高温电气设备，其标志为“e”。
3. 粉尘防爆电气设备
按规定条件设计制造，使其外壳能阻可燃粉尘进入或进入量不会防碍设备安全运行，内部堆积的粉尘也不易的产生点燃，从而保证
使用时不会引起周围爆炸性混合物的爆炸的电气设备。
1. isolation explosive electric equipment
withstanding for explosion pressure from interior mixed air also avoiding it spread out to exterior mixed air, mark d.
2. increasing safety electric equipment
in normal condition, it's without electric arc spark and high temperature up to ignite mixturer, it's structure adopts, safety step to avoid
appearing electric, spark and high temperature, mark e.
3. powder&dust electric equipment
on stated condition the enclosure can prevent dust entering or the interior dust will not ignite mixed air, so that ensure the surrounded
explosive mixed air will not be ignited.
注：
1. 粉尘防爆电气设备的温度组别与气体防爆电气设备的组别划分相同。
2. 粉尘防爆电气设备根据美标和欧标的差异分为a、b两种型式。a、b两种采用的试验方法不同，但保护的等级是等同的。
note:
1. dust explosive electric equipment and air explosive electric equipment temperature classes is the same.
2. according to america and europe standard difference. there are two kinds, the test ways of a and b is different, but protective class is
the same.