Hello everyone. I will soon be working with 3/0 wire. This is a much larger gauge wire than I typically use. I will have 3 conductors so I see that working with a metal enclosed conduit I need 1 1/2" conduit. If I have 4 conductors, then I will need to use 2" conduit. I only have 3, but I think I will go with the 2" conduit just to be safe. Here is my problem. I have a panel mounted disconnect, and the service wire (three 3/0 cables) will be coming in from through the rear of my machine (through the 2" conduit) and will immediately have to make 90 degree turn and fit into a panel mounted disconnect. I have about 4 inches from the conduit opening and the disconnect. Will it be impossible to make this bend in the 3/0 wire? Also, from the disconnect I will then go to a distribution block. What is the minimum spacing between the disconnect and the distribution block? It is open space, but I do not have much room. It is a straight shot to the distribution block so thankfully no bending, but I am looking at only about another 4 inches of space. Is it ok to have such a short run of cable coming from a panel mounted disconnect into terminal blocks? Hope I am making my questions clear here. Thanks in advance for sharing your experience and wisdom.
Working with 3/0 wire
- Thread starter fifty60
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Very helpful, thanks. I read through some earlier posts for 312.6 and it is a little more clear. I am entering through the back top of the panel, and the terminals to the disconnect are also at the top. I do not interpret "entering the opposite side" as being entering from the back. If it were entering the wall opposite of the terminals then I could see having to use table B. Since it is the entering from the back, I would think that I would use table A. But since the conduit entry is at the top and the disconnect is also at the top, do I have to use table B? Does 312.6 only apply to conductors and conduit entry points? The disconnect then connects to a distribution block on the panel that is opposite the disconnect terminals. Does 312.6 B apply to this situation, or only to conduit entry and exits? Also, is there a minimum spacing for the conduit entry from the back and the door of the enclosure when using specific wire gauges?
copper chopper
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- wisconsin
what the
what the
after reading your first post its hard for me to grasp exactly what you are attempting to do, could you provide any pictures? from what I can understand is it possible to install a gutter or junction box before you enter the panel and come in the back of that instead?
what the
after reading your first post its hard for me to grasp exactly what you are attempting to do, could you provide any pictures? from what I can understand is it possible to install a gutter or junction box before you enter the panel and come in the back of that instead?
Let me try to clarify. I have 3/0 conductors entering a sub panel from the top back wall of the sub panel. Perpendicular to the conduit opening on the top back wall of the enclosure I have the line side of a panel mounted disconnect. On the load side of the disconnect I will be connecting to a distribution block. My question is about distances between the line side panel mounted disconnect terminals and the conduit entry hole. The panel mounted disconnect is located at the top of my sub panel, but it is mounted at a 90 degree angle so the terminal lugs are facing right side wall of the sub panel enclosure. The conduit entry point is opposite the disconnect terminals but not on the side wall, they are coming in from the back of the sub panel enclosure. When I use 312.6 for this situation do I measure from the conduit hole in the rear of the chamber or do I measure from the wall opposite the the terminals. The three points (disconnect terminal lugs, center of conduit hole, and opposite wall) are all in a straight line. There is about a 2-3 inch difference from the center of the hole to the wall however. If I use table b, for instance and I measure from the center of the conduit hole i will be about 8 inches from the opposite wall. if i mesure from the wall using the table i will be 6.5 inches from the wall. The second part of my question is about the load side of the disconnect to the distribution block. Is there a minimum requirement for distance here? Can I have a 2 inch length of 3/0 cable connecting the load side of the disconnect to the distribution block, for example.
jumper
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Breathe, pause, and hit "enter" once in awhile...makes the post easier to read.
jumper
Senior Member
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- 3 Hr 2 Min from Winged Horses
This is one way you could break up your post so that it might be easier to read and respond.
IMHO, since your conductors are entering from the back of the cabinet, the wall "opposite" is the front (door side panel or door) so your cabinet depth must meet 312,6(B) or 6-1/2".
The width of your wiring gutter would need to comply with 312.6(A) which references Table 312.6(A).
The dimensions for any internal wiring would be regulated by the Code governing the construction of the panel, not the NEC.
In most jurisdictions the assembled panel would need to bear the label of a N.R.T.L., such as UL, to be accepted and assembly would have to meet the specifications of that NRTL. (I believe UL use UL508A).
The width of your wiring gutter would need to comply with 312.6(A) which references Table 312.6(A).
The dimensions for any internal wiring would be regulated by the Code governing the construction of the panel, not the NEC.
In most jurisdictions the assembled panel would need to bear the label of a N.R.T.L., such as UL, to be accepted and assembly would have to meet the specifications of that NRTL. (I believe UL use UL508A).
Thanks Sir. I was looking at some other posts on this very topic here at the Forum.
Would this apply to my situation: Code Cycle 2008 314.28(A) (2) Exception. Which states: Where a raceway or cable entry is in the wall of a box or conduit body opposite a removable cover, the distance from that wall to the cover shall be permitted to comply with the distance required for one wire per terminal in table 312.6(A)
So following this, I would need 4" between my conduit entry point at the back of the panel and the removable panel door.
Also, I am not sure I have a "Gutter" in this situation. My understanding of a gutter is basically "not a raceway". I think I would use a "gutter" if I had to deflect the wire when making a bend. I am not doing this. Would you consider the space between the conduit entry point and the panel mounted disconnect to be a gutter?
Thanks in advance.
Would this apply to my situation: Code Cycle 2008 314.28(A) (2) Exception. Which states: Where a raceway or cable entry is in the wall of a box or conduit body opposite a removable cover, the distance from that wall to the cover shall be permitted to comply with the distance required for one wire per terminal in table 312.6(A)
So following this, I would need 4" between my conduit entry point at the back of the panel and the removable panel door.
Also, I am not sure I have a "Gutter" in this situation. My understanding of a gutter is basically "not a raceway". I think I would use a "gutter" if I had to deflect the wire when making a bend. I am not doing this. Would you consider the space between the conduit entry point and the panel mounted disconnect to be a gutter?
Thanks in advance.
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