Squaring Out Cables Under House

[jmellc]

I was taught years ago to run cables in crawl space as the crow flies, point A to point B. Did that for a long time. Did other things for a living, came back to electrical in 95, doing commercial. Worked with a friend 03 & 04, wanted wiring squared out. I saw jobs done that way by others too. I did as the Romans did, but while it looks nice, I can't see the extra wire usually needed to do that & the extra time. I don't get much new work but I still crow fly on rewires.

What do the rest of you do?

 

[ActionDave]

The reason most of us do things the way we do is because that is the way we were told to do it the first time we did it. And that is why I square off.

The only advantage I can see to squaring off is when wiring a custom home you have some slack to use when homeowners decide they want a light or a plug moved... and they always want something moved.

 

[gndrod]

grid routing

grid routing

I was taught years ago to run cables in crawl space as the crow flies, point A to point B. Did that for a long time. Did other things for a living, came back to electrical in 95, doing commercial. Worked with a friend 03 & 04, wanted wiring squared out. I saw jobs done that way by others too. I did as the Romans did, but while it looks nice, I can't see the extra wire usually needed to do that & the extra time. I don't get much new work but I still crow fly on rewires.

What do the rest of you do?

Follow the grid for two reasons, even way back when.....1) [334.30] is not acceptable to many AHJ inspectors for sections of cable protected from damage 2) [300.4] Same in wiring methods where installed through or parallel to framing members [334.17] Reason...protection from in-wall physical damage that frequently occurs during other trades installations between stud and joist bays.

 

[jmellc]

I grant, it is neater and I can see some protection advantages but in some cases, squaring off means double the wire. No one these days wants to pay for anything to start with & that increases costs a lot.

 

[bumperlt]

I can't imagine running as the crow flies. Call me anal but it just looks terrible. If you have full access to the area being wired.. go with the building lines.

Even MC in grid I square it 98% of the time.

 

[Sparky555]

Conduit gets squared off in the basement and as the crow flies in the attic. I've never seen it any other way. I don't know about NM.

 

[kwired]

I can't recall seeing crows fly in a crawlspace. I've seen many bats though:grin:

 

[bullheimer]

best way as you said and you have no choice is 'do as the romans do".. i do like you though, however, since i brought it up. barrrf, i have seen in the new Handbook, where, i believe it says, you can no longer staple 12-2 to the bottoms of floor joists w/o a fur strip!!!?: they have to be on a backing board or else on the side of the joist.

care to comment on this guys, even tho its possibly another thread? if this is what they (NEC) are actually saying, are they out of their minds? or is it just me? in any case, i'm confused, as usual.

i refer to page 297 in the 2011 Handbook re Exhibit 300.2 and the commentary thereof.

i think i will post this querry in the NEC forum also.

 

[btharmy]

My take on NEC 110.12 is to follow the lines of the structure, thus squaring off my cable runs. However, mine are usually MC cable above suspended ceilings. I feel the same rules apply.

 

[kwired]

If you were an inspector would you cite 110.12 for someone that did not run cables parallel to framing members?

Neat and workmanlike is almost entirely opinion. Start throwing in terms like subject to physical damage or securing and support and you have more basis for rejection but you also have more than just 110.12 backing you up.

I see a lot of things others have done that may be ugly but are otherwise code compliant.

 

[btharmy]

If you were an inspector would you cite 110.12 for someone that did not run cables parallel to framing members?

I am not an inspector (thank goodness) but no. As I said it is simply my take on the article.

Neat and workmanlike is almost entirely opinion. Start throwing in terms like subject to physical damage or securing and support and you have more basis for rejection but you also have more than just 110.12 backing you up.

I obviously cannot force my interpretation on others installation, unless they work for me, then yes, they will square off their runs. Actually, the specs for two of the bigger G.C.s I do work with (commercial and industrial) note in the specs that "all electrical / mechanical runs are to follow the building lines and structure whenever possible." That means no "as the crow flies" cable or conduit. It's just what I'm used to.

I see a lot of things others have done that may be ugly but are otherwise code compliant.

Yes, but ugly may influence the decision to use, or not use you next time. It may also be reason for inspectors to take a second look at your install. Have a neat, professional install, inspectors, especially ones you build up relationship with, are less likely to nickle and dime you to death.

 

[kwired]

..Yes, but ugly may influence the decision to use, or not use you next time. It may also be reason for inspectors to take a second look at your install. Have a neat, professional install, inspectors, especially ones you build up relationship with, are less likely to nickle and dime you to death.

I have seen a lot of installs that are really neat looking from the exterior. Open up some enclosures and you find all kinds of things that indicate the installer did not know what they were doing. Like using white wires as ungrounded and black wires as grounded, wrong size overcurrent devices, wrong conductor sizes.

Nothing wrong with neat but when it is obvoius that neat had extra effort than normal especially on something that gets covered and never seen I would prefer to have some of the other things I have seen get more attention than the neatness of routing a cable.

Another thing I have seen a few times in panels is to use pliers to make very sharp 90 degree turns on conductors (12 and 14 AWG specifically). Although the installation looked neat I don't think it was such a good idea to make such a short radius bend. Conductor may be able to take it but will insulation eventually crack and separate from the conductor at this point?

 

[jmellc]

I have seen a lot of installs that are really neat looking from the exterior. Open up some enclosures and you find all kinds of things that indicate the installer did not know what they were doing. Like using white wires as ungrounded and black wires as grounded, wrong size overcurrent devices, wrong conductor sizes.

Nothing wrong with neat but when it is obvoius that neat had extra effort than normal especially on something that gets covered and never seen I would prefer to have some of the other things I have seen get more attention than the neatness of routing a cable.

Another thing I have seen a few times in panels is to use pliers to make very sharp 90 degree turns on conductors (12 and 14 AWG specifically). Although the installation looked neat I don't think it was such a good idea to make such a short radius bend. Conductor may be able to take it but will insulation eventually crack and separate from the conductor at this point?

THHN would probably take the bend OK, other types may or may not. I don't go to that kind of trouble. I think a finger bent 90 looks fine on panel installs. I tuck min such that a little play can still be had if an inch needs to be cut off in the future. I see a lot of that in service work. Over heated wire, charred insulation close to breaker.

I'm still torn on the squaring out. I like neat work but if I do it, it will be on basis of protecting my runs. Even then, I have never seen wire damaged by insulation installation, etc.

 

[bullheimer]

I'M subscribed to this thread so i answer.

panels, nice bends look great, take way too much time, and don't forget NOT to use cable ties, or cut them when you are done. i use fingers too like most.

i dont like to square EVERY run. if i have to go only about five to six feet i will go diagonally. i got into it BIG time with this hippy from oregon who didn't have a j card telling me over and over it was going to fail and the code says you have to square them. there is an article that states cable follow the framing members, this is true.
also yes, i have had inspectors come in, take one look at how wonderful stuff looked and basically sign it off right then.

but why i reply is your comment that "you haven't seen cable damaged by insulation installers".

i had a afci tripping i couldn't find forever in a house we just wired and it was because the insulation installer in the attic kicked the wire up 90 degrees from a staple!! this was a few years ago, the cable didn't seem damaged but once i straightened it back out the breaker quit tripping. there was about three hours worth of work i did NOT get paid for tearing apart switches and recepts. one of the many reasons i HATE AFCI'S.

 

[kwired]

I'M subscribed to this thread so i answer.

panels, nice bends look great, take way too much time, and don't forget NOT to use cable ties, or cut them when you are done. i use fingers too like most.

i dont like to square EVERY run. if i have to go only about five to six feet i will go diagonally. i got into it BIG time with this hippy from oregon who didn't have a j card telling me over and over it was going to fail and the code says you have to square them. there is an article that states cable follow the framing members, this is true.
also yes, i have had inspectors come in, take one look at how wonderful stuff looked and basically sign it off right then.

but why i reply is your comment that "you haven't seen cable damaged by insulation installers".

i had a afci tripping i couldn't find forever in a house we just wired and it was because the insulation installer in the attic kicked the wire up 90 degrees from a staple!! this was a few years ago, the cable didn't seem damaged but once i straightened it back out the breaker quit tripping. there was about three hours worth of work i did NOT get paid for tearing apart switches and recepts. one of the many reasons i HATE AFCI'S.

If the cable was following a framing member it won't be able to get disturbed in this manner as easily. I don't always follow framing members either but this is a possibile risk in doing so. Most new homes around here are getting blow in insulation or spray foam or combination of both. Insulators do not disturb many cables. They may fill boxes - have not had one filled with spray foam - yet.

 

[petersonra]

Another thing I have seen a few times in panels is to use pliers to make very sharp 90 degree turns on conductors (12 and 14 AWG specifically). Although the installation looked neat I don't think it was such a good idea to make such a short radius bend. Conductor may be able to take it but will insulation eventually crack and separate from the conductor at this point?

An OEM (now defunct) I used to do work with had some machine wirers that actually welded a couple pieces of angle to a pair of vise grips so they could shape wires in this way. I cringed when they showed me what they were doing. They were quite proud of their invention.

The same guys were quite proud of themselves when they discovered some wire rated for 200 deg C that they started using to wire up the motors in their machines. The 200 deg C wire allowed for much smaller wire sizes than the THHN they were previously using according to the manufacturer's charts. I did not even try to tell them how wrong this was. Some things are just not worth arguing over.

 

[kwired]

An OEM (now defunct) I used to do work with had some machine wirers that actually welded a couple pieces of angle to a pair of vise grips so they could shape wires in this way. I cringed when they showed me what they were doing. They were quite proud of their invention.

The same guys were quite proud of themselves when they discovered some wire rated for 200 deg C that they started using to wire up the motors in their machines. The 200 deg C wire allowed for much smaller wire sizes than the THHN they were previously using according to the manufacturer's charts. I did not even try to tell them how wrong this was. Some things are just not worth arguing over.

200 deg conductor may be fine to load more than 75 deg conductor but you still have to consider the temperature of terminations, which most of the time gets you back to 75 deg ratings. 200 deg conductor should be used for ambient temp purposes and not higher ampacity purposes.

 

[petersonra]

200 deg conductor may be fine to load more than 75 deg conductor but you still have to consider the temperature of terminations, which most of the time gets you back to 75 deg ratings. 200 deg conductor should be used for ambient temp purposes and not higher ampacity purposes.

I forget exactly what the number was but it was a DC motor and the extra voltage drop on the smaller wires was costing their machine almost 10% of the max speed the motor might have otherwise been able to get at max load. It was a number that surprised me when I calculated it.