Terminal Block in Class I Div. 2

[Yossi.S.T]

Is the Terminal Blocks which are installed in hazardous area Class I Div.2 in a certified NEMA 4X enclosure, need approval for hazardous area with Class I Div.2 marking?
I do not find in NEC Section 500 any mention of terminal block. and if possible to Substantiate the argument from NEC to the supervisor?

 

[don_resqcapt19]

The is no requirement for any special type of terminal block or other wire connection device in a Class I, Division 2 area.

 

[Yossi.S.T]

The is no requirement for any special type of terminal block or other wire connection device in a Class I, Division 2 area.

How i can see this matter in the NEC that there is no requirement for terminal block in a Class I, Division 2 area

 

[Dennis Alwon]

How i can see this matter in the NEC that there is no requirement for terminal block in a Class I, Division 2 area

You want find anything that says there is no requirement but the fact that the section does NOT state that you are required to have terminal block means that you do not need one

 

[rbalex]

Don (don_resqcapt19) said there is no requirement. Dennis says that, in absence of a requirement, there is none. Both are correct.

You and your supervisor are probably operating under the influence of IEC Zone concepts where terminals must be Type "Ex e", Increased Safety as a minimum in Zone 1 or 2. There is no such requirement in the NEC - even in NEC Zones whether 0, 1 or 2.

Historically, IEC assumes terminals can vibrate free. That is a problem in Zone 1 since enclosures may not necessarily be Type "Ex d" or other suitable protection technique, but it is still not required in NEC Zones (1 or 2).

For most (not necessarily all) IEC Zone 1 locations are actually only an upgraded Zone 2. Despite the erroneous, but common, US manufacture's analysis, IEC Zone 1 is NOT the same as NEC Division 1 or vice-versa. Anyone that has properly classified a location under the IEC system knows that. NEC Zone 1, was "force-fit" into Division 1.

Because of my familiarity with both systems I often specify vibration-proof terminals (essentially Type "Ex e" ) in high vibration locations, such as reciprocal compressors. It is still is not an NEC requitrement.