Differences in Class I Div 1 and Div 2 Wiring Practices.

[DownRiverGUy]

Hey Guys,

My 2005 NEC has a cute little diagram (p679, Exhibit 501.8) showing Div 1 practices. Is there a diagram showing Div 2 practices?

In a Div 2 location are there less requirements for seal locations, switches, junction boxes etc?

I know that the light fixtures have to be rated for the location but I am unsure when and where I need to use explosion proof items etc.

If I need to provide anymore information please let me know.

Thanks guys!

 

[Inspectorcliff]

Hey Guys,

My 2005 NEC has a cute little diagram (p679, Exhibit 501.8) showing Div 1 practices. Is there a diagram showing Div 2 practices?

In a Div 2 location are there less requirements for seal locations, switches, junction boxes etc?

I know that the light fixtures have to be rated for the location but I am unsure when and where I need to use explosion proof items etc.

If I need to provide anymore information please let me know.

Thanks guys!

501-15 and 502.15 should give you ample information. If not, in the 08 handbook are some good articles that may help you with your question.

 

[weressl]

Hey Guys,

My 2005 NEC has a cute little diagram (p679, Exhibit 501.8) showing Div 1 practices. Is there a diagram showing Div 2 practices?

In a Div 2 location are there less requirements for seal locations, switches, junction boxes etc?

I know that the light fixtures have to be rated for the location but I am unsure when and where I need to use explosion proof items etc.

If I need to provide anymore information please let me know.

Thanks guys!

Your question is VERY general. Hazardous area installations are far more complex than what can be answered with a simple answer.

Having said that there is a basic principle that can be put in a short sentence that can help you understanding the OBJECTIVE of the area classification philosophy and approach.

A source of ignition can be either an electric arc or heat produced as the result of electricity. In Division I areas anything electrical that can produce either operationally or by a fault a source of ignition should be confined into an enlcosure that can withstand and contain an explosion. If the enclosure has openings, they should be sealed so the confinement is limited to the volume or close to the original volume of the enclosure. In Division 2 electrical components that are not normally represent a source of ignition either by their nature of construction or by test during NORMAL operation can be supplied in a non-explosionproof enclosure. Hermetically sealed switches, lighting fixtures that have a Div2 T-rating are some of the examples. Obviously these do not require seals, since they are not built for explosion containment.