Class 1 locations

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Flex

Senior Member
Location
poestenkill ny
Anyone know where I can get a better understanding of the different locations. Im not familiar with the subject at all. Id like to have a better understanding.
 

Goroon

Member
Hazardous (Classified) Locations

Hazardous (Classified) Locations

Focus on 500 through 504. 505 and 506 are Zone catagories that may confuse those seeking to understand Hazardous (Classified) Locations.
My understanding is Zones were added for european standards in the 1999 edition. First NFPA 70 code as an 'International Standard"
 

charlie

Senior Member
Location
Indianapolis
By the way, focus on understanding the type of wiring methods needed for the different locations, what type of equipment is required in the location, where seal-offs are to be located, etc. The actual classifications are to be done by an engineer but it is good to have a cursory understanding of what constitutes the various locations. :smile:
 

Goroon

Member
Engineer Required, unfortunatly 2008 has a new hitch.

Engineer Required, unfortunatly 2008 has a new hitch.

This one single change has upped my attendance in Chapter 5 classes.

"505.7 Special Precaution.
(A) Implementation of Zone Classification System. Classification of areas, engineering and design, selection of equipment and wiring methods, installation, and inspection shall be performed by qualified persons."

Persons not understanding the basics of 500-504 are trying to use 505 and 507 that now use the term "Qualified person" to get around the cost of the engineer.

This is very good advice:
The actual classifications are < or should be > to be done by an engineer but it is good to have a cursory understanding of what constitutes the various locations
 

radiopet

Senior Member
Location
Spotsylvania, VA
Anyone know where I can get a better understanding of the different locations. Im not familiar with the subject at all. Id like to have a better understanding.

The NFPA sells a great book on understanding Hazardous Locations.

Electrical Installations in Hazardous Locations, 2008 Edition
by Peter Schram, Mark W. Earley, and Robert J. Benedetti
Electrical Installations in Hazardous Locations provides a basic and critical understanding of fire and explosion safety.

This 3rd edition of Electrical Installations in Hazardous Locations includes vital information on the availability of new technology, as well as national and international codes and standards. NFPA?'s practical guide explains the intricate details of performing electrical installation in specialized sites. It's a vital introduction to what hazardous locations are--and what they are not.

I can tell you this, if it has Mark Earley in it then it will be a good book.
 

templdl

Senior Member
Location
Wisconsin
Class I Locations

According to the NEC, there are three types of hazardous locations. The first type of hazard is one which is created by the presence of flammable gases or vapors in the air, such as natural gas or gasoline vapor. When these materials are found in the atmosphere, a potential for explosion exists, which could be ignited if an electrical or other source of ignition is present. The Code writers have referred to this first type of hazard as Class I. So, a Class I Hazardous Location is one in which flammable gases or vapors may be present in the air in sufficient quantities to be explosive or ignitable. Some typical Class I locations are:
Petroleum refineries, and gasoline storage and dispensing areas;
Dry cleaning plants where vapors from cleaning fluids can be present;
Spray finishing areas;
Aircraft hangars and fuel servicing areas; and
Utility gas plants, and operations involving storage and handling of liquified petroleum gas or natural gas.
All of these are Class I . . . gas or vapor . . . hazardous locations. All require special Class I hazardous location equipment.

There are three types of hazardous conditions: Class I - gas and vapor, Class II - dust, and Class III - fibers and flyings.

There are two kinds of hazardous conditions: Division 1 - normal, and Division 2 - abnormal.

Ref: http://www.osha.gov/doc/outreachtraining/htmlfiles/hazloc.html
 
By the way, focus on understanding the type of wiring methods needed for the different locations, what type of equipment is required in the location, where seal-offs are to be located, etc. The actual classifications are to be done by an engineer but it is good to have a cursory understanding of what constitutes the various locations. :smile:

I would replace the 'good to have" with ' must have' and 'cursory' with 'good'.:smile:
 

edavis2293

Member
Location
Houston, Texas
Hazardous Locations

Hazardous Locations

Contact Crouse Hinds and request a copy of code digest. Its free and has illustrated explanations of all Class and Divisions. Appleton has the same type book, also free and illustrated.

We work hazardous locations every day on probably 95% of our projects. These two books clear up what the NEC is trying to say including IEC Zone explanations and most of what the NEC doesn't say.
 
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