Cable protection

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triniboy

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In NEC section 300.5(D)(1) it states that

Emerging from Grade. Direct-buried conductors emerging from grade shall be protected by enclosures or raceways extending from the minimum cover
distance below grade required by 300.5(A) to a point at
least 2.5 m (8 ft) above finished grade. In no case shall the
protection be required to exceed 450 mm (18 in.) below
finished grade.
My question is on the protection above grade I maintain that if cable tray is used the cable tray mujst be covered front and back if the back is accessable am I correct in this assumption.

Triniboy
 
triniboy said:
In NEC section 300.5(D)(1) it states that

Emerging from Grade. Direct-buried conductors emerging from grade shall be protected by enclosures or raceways extending from the minimum cover
distance below grade required by 300.5(A) to a point at
least 2.5 m (8 ft) above finished grade. In no case shall the
protection be required to exceed 450 mm (18 in.) below
finished grade.
My question is on the protection above grade I maintain that if cable tray is used the cable tray mujst be covered front and back if the back is accessable am I correct in this assumption.

Triniboy
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I would think so, but I've never dealt with that scenario.
 
triniboy said:
In NEC section 300.5(D)(1) it states that

Emerging from Grade. Direct-buried conductors emerging from grade shall be protected by enclosures or raceways extending from the minimum cover
distance below grade required by 300.5(A) to a point at
least 2.5 m (8 ft) above finished grade. In no case shall the
protection be required to exceed 450 mm (18 in.) below
finished grade.
My question is on the protection above grade I maintain that if cable tray is used the cable tray mujst be covered front and back if the back is accessable am I correct in this assumption.

Triniboy
Click to expand...

Is cable tray even listed for conductors. T. 329.3(A) doesn't appear to list conductors but rather cables and raceways.
 
I am from the UK so maybe the cable tray description is not what you would describe the cables running on do you guys understand ladder rack that is what the cables will be running on does that make it clearer.

Triniboy
 
I would tend to agree that the cable tray would need to be enclosed since art 300.5 says enclosures or raceways. I don't think cable tray meets the definition of raceway so it would bneed to be enclosed.

Raceway. An enclosed channel of metal or nonmetallic materials designed expressly for holding wires, cables, or busbars, with additional functions as permitted in this Code. Raceways include, but are not limited to, rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquidtight flexible conduit, flexible metallic tubing, flexible metal conduit, electrical nonmetallic tubing, electrical metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface raceways, wireways, and busways.
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We normally stop the cable tray about four feet above the ground (see392.6(A), and put an "S" bend in the wire to allow for ground motion in the Arctic (Allows for permafrost).

We don't cover our tray either. If a tray cover would be required, then 392.3 wouldn't mention - Where exposed to direct rays of the sun, insulated conductors and jacketed cables shall be identified as being sunlight resistant. Cable trays and associated fittings shall be identified for the intnded use.
 
Dennis Alwon said:
Then why would the op be asking about it. Some areas in Europe are starting to use the NEC, I believe.
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All he said is he is FROM the UK not that he is in the UK. He may be on either side of the pond.
 
Rockyd said:
We don't cover our tray either. If a tray cover would be required, then 392.3 wouldn't mention - Where exposed to direct rays of the sun, insulated conductors and jacketed cables shall be identified as being sunlight resistant. Cable trays and associated fittings shall be identified for the intnded use.
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Could that mean exposed above the required 8' above the ground?
 
Dennis,

The cables are not going anywhere in a ladder tray. It's normally nine inches between runs on the tray we use. On the straight sections we normally tywrap every fourth rung, and going around corners, we go one, skip two, one, skip two, till yor back on easy running.
 
8 foot?

In the oil patch MCHL cable has become the industrial romex. To route it, it is normally ran in cable trays, dropping off cables to their respective connections as they go. Caddy makes a cables strap to strut, since we normally only use strut when you leave the tray for support.

* I turned if a code change proposal to extend the distance from a box to first support leaving "motor terminal boxes" to follow in the same logic as 350.30 to apply to 330.xx
 
Rockyd said:
Dennis,

The cables are not going anywhere in a ladder tray. It's normally nine inches between runs on the tray we use. On the straight sections we normally tywrap every fourth rung, and going around corners, we go one, skip two, one, skip two, till yor back on easy running.
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I am way out of my league on this so I will have to defer to you. I am trying to make sense of the section but I keep running into road blocks-- :smile:.

It just seems like the code requires protection to above 8' where it emerges from grade. I don't see a cable tray or ladder rack as protecting the wires without covers.
 
In 300.5(D)(4) it talks about protection from damage. Exiting the ground in the frozen north, the risk is in having things solidly attached. They need to be able to move.

The danger of permafrost (in US and Canada, top of Europe) is that it will push pipe into a box if entering from directly underneath. Easiest way around the problem is to use a piece of Seal-tite, or MC-HL cable, and put an (expansion) "S" into it, so that the motion range is covered.

There is a spot in the NEC covers exiting ground (other than 300.5) see if I can find it.
 
Yes guys I am from the UK but working in Peru on an NEC coded project, the aim of my question was to find out does the cable tray that is holding the cables that emerge from below grade have to be covered front and back I know the front does but if the back was accessable does it have to be coverecd to comply with NEC 300.5(D)(1)
 
Depends on the type of cable tray (ladder). I don't see the need to cover top, or bottom. as long as the cable is rafed sun resistant(330.10(B)(1) and the associatedsections in 392).

Without being there, unless there is a reason to actually protect the cables (theft, wildlife, harsh environment) I wouldn't cover either side. A call to the cable tray manufacturer may help.
 
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