junction box vs. terminal enclosure

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Designer69

Senior Member
where do you draw the line whether an electrical box is a junction box or a terminal enclosure?

is it defined somewhere?

thank you
 

eric9822

Senior Member
Location
Camarillo, CA
Occupation
Electrical and Instrumentation Tech
What is the difference between a junction box and a terminal enclosure? I have always thought of them as the same thing.
 

Designer69

Senior Member
well the reason I ask is because the NEC requires working space clearance for electrical equipment. I am sure that includes electrical enclosures and terminal housings, but what about a junction box with a removable front cover? see what I mean?

thanks!
 

jim dungar

Moderator
Staff member
Location
Wisconsin
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Retired Electrical Engineer - Power Systems
Junction box = box with no components mounted in it (i.e. all connections are wirenuts or split bolts). Most conductors are long enough to be pulled from the box (i.e. the 6" length required at devices)

Terminal box = box with components (i.e. terminal strips) mounted in it. Most conductors are trimmed to length to fit into terminal (like in a load center).
 

eric9822

Senior Member
Location
Camarillo, CA
Occupation
Electrical and Instrumentation Tech
Junction box = box with no components mounted in it (i.e. all connections are wirenuts or split bolts). Most conductors are long enough to be pulled from the box (i.e. the 6" length required at devices)

Terminal box = box with components (i.e. terminal strips) mounted in it. Most conductors are trimmed to length to fit into terminal (like in a load center).

I should have phrased my question/statement better, functionally they are the same thing. Now that I see the OP's reason for asking I understand better.

well the reason I ask is because the NEC requires working space clearance for electrical equipment. I am sure that includes electrical enclosures and terminal housings, but what about a junction box with a removable front cover? see what I mean?

thanks!

I would say Jim's definitions are right on. Junction boxes need to be accessible but don't require working clearance. Terminal boxes would require working clearance.
 

Gategator37

Senior Member
They do make a clamp that will connect an EMT conduit to a cable tray, it looks like a unistrut clamp. I am in a hurry now but will try to find a link for you later.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
well the reason I ask is because the NEC requires working space clearance for electrical equipment. I am sure that includes electrical enclosures and terminal housings, but what about a junction box with a removable front cover? see what I mean?

thanks!


Equipment. A general term including material, fittings, devices,
appliances, luminaires (fixtures), apparatus, and the
like used as a part of, or in connection with, an electrical
installation.
I don't see how a junction box is not equipment. If fittings are equipment, a junction box is.
 

eric9822

Senior Member
Location
Camarillo, CA
Occupation
Electrical and Instrumentation Tech
I don't see how a junction box is not equipment. If fittings are equipment, a junction box is.

Sure it's equipment. But is it equipment likely to require examination, adjustment, servicing, or maintenance while energized? I wouldn't think so.
 
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