1. Overview of Explosion Protection
1-5
TI 33Q01J30-01E
Oil Immersion (Type “o”)
1) Definition: “Oil immersion” is an explosion protection construction that a part of electric
machine and apparatus, which may create sparks or arcs and may become an ignition
source by unacceptable high temperature, is immersed in insulating oil, so as not to ignite to
gas or vapor.
2) Construction
Insulating oil
F010304.ai
* The electric circuit immersed in insulating oil.
* It restricts the surface temperature of enclosure and oil.
Figure Oil Immersion (Type “o”)
Intrinsic Safety (Type “i”)
1) Definition: “Intrinsic safety” is the explosion protection construction confirmed that the
sparks, arcs or heat, which the component part of the electric machine and apparatus
create, have no possibility of ignition to gas or vapor, by the spark ignition test and so on.
2) Construction
Energy restriction
Barrier
F010305.ai
* It has no ignition to gas, even if it's under
abnormal situation.
• It restricts the electric energy.
• Creepage distance/insulation distance is kept.
• It restricts the surface temperature of electric
component and so on.
* A barrier is necessary.
* IP22 enclosure (technical standard)
Figure Instrinsic Safety (Type “i”)
Encapsulation (Type “m”)
1) Definition: “Encapsulation” is the explosion protection construction that parts which may
ignite potentially explosive atmospheres by heating are embedded in sealing compound, so
that potentially explosive atmospheres cannot be ignited.
2) Construction
Mold
F010306.ai
* The electric circuit is encapsulated by resin.
* It restricts the surface temperature of enclosure and resin.
Figure Encapsulation (Type “m”)
Mar. 26, 2015-00
