basics for class 1 div2

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stev11

Member
Location
india
hi

I am new in this field and I have some basic questions in class 1 div 2 as follow:-

1-is it allowed to use plastic terminals in junction boxes to connect the wires.
terminal.jpg

2-Can i use ul listed components like elbows,reducers in any place (except between the ex proof box and sealing fitting)??

3-can i use ex proof components that is certified for cl 1 div1 group A in cl 1 div1 group d ???


thank you.
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
hi

I am new in this field and I have some basic questions in class 1 div 2 as follow:-

1-is it allowed to use plastic terminals in junction boxes to connect the wires.
View attachment 8741

2-Can i use ul listed components like elbows,reducers in any place (except between the ex proof box and sealing fitting)??

3-can i use ex proof components that is certified for cl 1 div1 group A in cl 1 div1 group d ???


thank you.
These answers apply only to the US National Electrical Code (NEC) installations. There are some philosophical differences with IEC.

While we are at it let?s get you started right. ?Class? is an upper case, Roman numeral; i.e., ?I?, "II" or ?III?. ?Division? is an Arabic ?1? or ?2?. ?Class?, ?Division?, and ?Group? may be abbreviated, but should still be capitalized. I rarely make a big deal of this ? but since you?re new to the field and learning the basics.

1. ? Yes. NEC does not consider properly installed terminals to be arcing, sparking or heat producing ? sometimes referred to as ASH.

2. ? Not necessarily. There are some other restrictions on acceptable wiring methods In Class I, Division 2. See Section 501.10(B).

3. ? Theoretically, no; practically, yes. Section 500.8(C)(3) requires ?[t]he marking shall specify the applicable material classification group(s) in accordance with 500.6?. If the item were only marked for Group A, it wouldn?t be suitable Group D. I have never seen something marked for Group A that wasn?t also marked for Groups B, C and D.
 

stev11

Member
Location
india
3. ? Theoretically, no; practically, yes. Section 500.8(C)(3) requires ?[t]he marking shall specify the applicable material classification group(s) in accordance with 500.6?. If the item were only marked for Group A, it wouldn?t be suitable Group D. I have never seen something marked for Group A that wasn?t also marked for Groups B, C and D.

I saw that for ATEX and CLASS/ZONE(NEC 505) components .

also
1- it is allowed to use non metallic flexible conduit (PVC) with non metallic cable gland in CLASS I DIV 2???
View attachment 8746
2-it is allowed to use plastic cable tie to support the conduits???
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
I saw that for ATEX andCLASS/ZONE(NEC 505) components .

also
1-
it is allowed to use non metallic flexible conduit (PVC) with non metalliccable gland in CLASS I DIV 2???
View attachment 8746
2-
it is allowed to use plastic cable tie to support the conduits???
ATEX does not apply to NEC installations - Divisions or Zones. Zones don’t use Groups A, B, C or D.
1. See Subsection 501.10(B)(2)(4); make sure you ground/bond properly per Section 501.30.
2. That’s a matter of opinion; I don’t recommend it in hazardous locations. See Section 344.30.
You need to quit trying to apply IEC concepts to NEC designs. I know how to do both, but I won’t tell you how to do it here. Please see Section 90.1(C).
 
Last edited:

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer

it is allowed to use plastic cable tie to support MC HL CABLE OR LFNC in CLASS I DIV 2???
Yes, both are relatively light weight. Section 330.30 specifically permits cable ties for Type MC. Both are still required to be securely fastened. See Section 356.30 for LFNC as well. Be sure to read their respective Articles for other installation restrictions that may apply.

Be VERY careful to avoid locating either of them where they would be ?? subject to physical damage.? In the US, ?subject to physical damage? is a debatable topic in its own right and I can?t give you specific directions. It is usually up to the judgment of the authority having jurisdiction (AHJ) and I can barely read my own mind, let alone one several thousand miles away.
 

stev11

Member
Location
india
hi

I have ex proof SOLENOID VALVE coil CLASS 1 DIV 1 but this coil has non re-settable thermal fuse inside the coil[FONT=Calibri, sans-serif] and [/FONT]There also are no factory sealed label on the coil but the coils are one piece molded in epoxy with no internal volume .

so, Can i consider this coil to be factory sealed and there is no need for seal fitting??
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
hi

I have ex proof SOLENOID VALVE coil CLASS 1 DIV 1 but this coil has non re-settable thermal fuse inside the coil[FONT=Calibri, sans-serif] and [/FONT]There also are no factory sealed label on the coil but the coils are one piece molded in epoxy with no internal volume .

so, Can i consider this coil to be factory sealed and there is no need for seal fitting??

I would be looking at the manufacturer's instructions for this device to determine if whatever sealing it may or may not have is considered adequate.

Whether it needs an external seal or not is something entirely different. The sealing requirements for Div 1 are not as straight forward as one might like, especially for stuff like this. You have to read what the code actually says.
 

stev11

Member
Location
india
thank you for your reply.

i Have a reply from the manufacturer as follow: you can consider it as factory sealed because it is one piece molded in epoxy with no internal volume.

but if this correct, why they did not write it is factory sealed.

thank you.

 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
since it is div 2 according to the title of your post, why does it even matter?

once again, instead of beating around the bush like this, you really need to be forthcoming about what you are trying to do if you want answers that are meaningful.
 

stev11

Member
Location
india
wire nut

wire nut

hi

Is acceptable to use wire nut (twisted on wire connector) instead on terminals in C1D2 locations???
 

hardworkingstiff

Senior Member
Location
Wilmington, NC
hi



2-Can i use ul listed components like elbows,reducers in any place (except between the ex proof box and sealing fitting)??

I'm not sure exactly what you are asking here, but I would like to point out that if you don't have an X-proof union (or something) in between the seal fitting and the junction box, you will never be able to disconnect the junction box from the conduit system after the seal is poured. If this junction box is on a piece of equipment that might one day need to be removed, you are screwed.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I'm not sure exactly what you are asking here, but I would like to point out that if you don't have an X-proof union (or something) in between the seal fitting and the junction box, you will never be able to disconnect the junction box from the conduit system after the seal is poured. If this junction box is on a piece of equipment that might one day need to be removed, you are screwed.

what's wrong with a hacksaw?

:)

this is a good point. being able to repair or replace a defective piece of equipment is a good thing.

He might be trying to ask about the boundary seal where you aren't allow to have anything in the pipe between the seal and the boundary.
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
I believe he was asking if UL listed materials were all that was necessary in Division 2 beyond an explosionproof enclosure seal. A boundary seal wasn't the issue.
 
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