FUN WIRE PULL – got ideas…
The inspector would really like to have me pull a ground wire in this old feeder. I bonded the conduit and hoped. Nope. Aside from that the inspection went well. Couple of small items to tidy up.
60A service to a two BR apartment, built when. Three #6 run in 1.25″ FMC from second floor down and over to the meters outside.
I need to run a #8 in the same conduit. Past experience with smaller conduits suggests this is not going to be a fun day. Even wondered if I could suck a string thru, but somehow I suspect FMC to be less than air tight.
Anyone got some good ideas?
I plan to see if I can trace the run using my Amprobe or bring in the Tempo we use for underground work. Need to know how much wire. Would love string. Recall some that had feet marked out and it was a snap to figure the length of the conduit.
The ToolBear
“You can’t save the Earth unless you are willing to make other people sacrifice.” Dogbert
Replies
Pull the old wire out, pull in all new wire.
You don't say how old the feeder is, but if it has THW insulation (or RW), your chances of getting another wire in the flex with the three #8s in it are none to slim.
Pulling in four new conductors, all with THHN insulation, may be a grunt but will be do-able. Unless of course the original installer ran the wire into the conduit first, and the conduit has a lot bends in it. BY a lot, I mean more than 270 degrees.
Pull the old wires out one at a time. On the last wire, use it to pull in mule tape and use a lot of yellow 77 lube. Then use the mule tape to pull on the new conductors. And use a whole lot of yelow 77. When you make up the head for the pull, stagger the conductors so the bundle is streamlined.
If you want to try it, you could use a fiberglass fish and a lot of yellow 77 and try to get the fish through the flex, and pull the #6 back. You may get the fish stuck, jamming the whole thing up.
Good luck.
Cliff
Pull the old wire out, pull in all new wire.You don't say how old the feeder is, but if it has THW insulation (or RW), your chances of getting another wire in the flex with the three #8s in it are none to slim.@@@ We think it dates from '70sPulling in four new conductors, all with THHN insulation, may be a grunt but will be do-able. Unless of course the original installer ran the wire into the conduit first, and the conduit has a lot bends in it. BY a lot, I mean more than 270 degrees.@@@ The joisting runs the long way, so I suspect they dropped into the ceiling cavity below the panel (90) and headed for the meter array (90). Perhaps 3 - 90s. @@@ There has been talk of upgrading the units to have a stackable laundry in the front closet, which means at least 75A of service. Some units have been converted. It would be tempting to pull out the old and in with the new in CU, not AL.,Pull the old wires out one at a time. On the last wire, use it to pull in mule tape and use a lot of yellow 77 lube. Then use the mule tape to pull on the new conductors. And use a whole lot of yelow 77. When you make up the head for the pull, stagger the conductors so the bundle is streamlined.@@@ Right.If you want to try it, you could use a fiberglass fish and a lot of yellow 77 and try to get the fish through the flex, and pull the #6 back. You may get the fish stuck, jamming the whole thing up.Good luck.The ToolBear
"You can't save the Earth unless you are willing to make other people sacrifice." Dogbert
the problem is the flex, but try pulling one wire out and pull a string in, then pull the wire back in along with the new ground. use ALL the lube out and in
or like CAP wrote, pull them all out, just don't wreck them
either way I think you are going to be in a bad mood trying to refeed something thru that greenfield ........ hopefully the connectors have a real good grip on the flex, but I doubt it
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There are more than several things that can go wrong.I am making a list <g>. Gonna be a fun time.See if I can trace the run and get a feel for the turns.The ToolBear
"You can't save the Earth unless you are willing to make other people sacrifice." Dogbert
I have successfully sucked a string through rigid but never greenfield.
>>never greenfield.<<
Not airtight enough, rigid yes, PVC yes, usually emt, greenfeld leaks air like a sieve.
Jim
Never underestimate the value of a sharp pencil or good light.
I have successfully sucked a string through rigid but never greenfield.@@@I bet it's as airtight as a sponge. If not, the conductors are probably twisted about. I've done underground runs that went well and one that was a real problem. The conduit was pulled into the slant drilled bore. We suspect that a joint parted. They would glue, then screw the joints, but 18' in we kept hitting clay in the conduit. Finally got a string thru and then it went.The ToolBear
"You can't save the Earth unless you are willing to make other people sacrifice." Dogbert
I would go with the already suggested techniques of pulling at least one of the wires back with a "fish string" attached to it.
I would actually attach the end of a piece of a flat nylon fish tape to the wire being pulled back. The flat nylon which I have is marked numerically in feet along its entire length. ~ 1/2" wide, very strong, I have seen it pulled with the aid of a backhoe and not break.
Attach conductors to the nylon tape with tape and in a staggered pattern to ease around the bends, shortest conuctor leads the pack.
Would not be a bad idea to independently attach both the nylon tape and a light string to the initial conductor being pulled out -- leave string in place until all fishing operations are completed ------ just in case.......
Need to go from point A to B? - difference in the numbers at A vs B = length of wire needed --- plus whatever you need to make the connections at the two ends.
Worst case would be pulling back all wires and haul back in along with the new ground wire.
Everybody else mentioned lube, good idea.......
You never said - roughly how long is this run?
Jim
The meters are one floor down and about 2.5 bedrooms over. I hope that's under 100. Certainly under 200'I like the idea of tape vs rope. I will see if Walter's has something and I am sure they do. Plus a string! Just in case. The stuff I used to use when doing cell sites was about 1/4 wide, with numbers.The ToolBear
"You can't save the Earth unless you are willing to make other people sacrifice." Dogbert
Well ?
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Well...Well, home and dry, as the Brits put it.@@@ After Action Report...The #8 CU ground is mounted and the panel is back together. Here is what happened.The pull was about 45' with turns.Made two tries with my 100' fish tape with a springie thingie on the end. Both got stopped down near the meter farm in the clubhouse turn. Could not exit into the meter farm - where I had rigged shields of #200 cardboard around hot bits.Move to Plan B - Pull One Conductor.Unhooked the feeders at the subpanel, unhooked the red down at the meter, unhooked the FMC and, being a sailor by trade, rigged a handy billy (3:1 tackle)to a joist. Secured a bit of small stuff to the red conductor conductor using a large (many turns) rolling hitch (very useful knot) and bowsed it up taunt. Gave it a swig (sideways pull) and it came loose. Got some in. Stuck again. Rerigged the handy billy and repeatede. Then it came in hand over hand. (Once it's moving, don't you stop.) Pull cord came in behind it.Laid it out on the lawn, measured it and went off to get 50' of #8 (little bit extra is so much better than a little bit short). Laid out 100' of pull cord so I could send a pair up the FMC. Not that I don't trust this stuff, but it ain't mule tape and you can't pull it with a backhoe (very long). The local POCO pulls on 3/8 poly, one use only. Stripped #8 and did an eye for the start of the cord. Taped same. Lashed the red #6 to it, down about a foot. Secured the pair with a series of rolling hitches with runs between using doubled pull cord. Taped all this over. We now have pull cord secured to the wires over a length of several feet. Spreads the strain.Made up the pair, stopping them with painters tape about every 4'.Took the mess over to the meters, laid out the wires, attached doubled cord to line in conduit, pulled it up to panel. Sergio got to pull upstairs while I slobbered yellow lube over the wires. Wore rubber gloves. Poured a mess into a shop towel and lubed up the wire in sections. First few feet were iffy. To and fro a bit. Clubhouse turn up in the doghouse. Then it began to move once the head cleared the turn. Pull, pause, lube, pull. Came home nicely. Took longer to get the tape and many turns of pull cord off the wires than it did to pull it. Like painting: 90% prep. They did not elect to do the upgrade, or I would have pulled a whole fresh set of CU feeders to give 75 amps topside.@@@I think the moral of this job was - when you see a maxed out 6/12 Zinsco filled with half height breakers, put in a 20/40, not a 12/24.The ToolBear
"You can't save the Earth unless you are willing to make other people sacrifice." Dogbert
Good story. I wish i knew more about what you were saying though lol.
always keep the trick bag full,
we use snatch blocks, handrails, lift trucks, pickups, comealongs, more people, and once in a while the chugger... Gravity is our friend ! and wire through flex goes easier with the coil than against itand you didn't wreck anything...
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Way to go!
JimNever underestimate the value of a sharp pencil or good light.
The inspector would like to have you do this or code require it?
If you have continuity in the conduit and this is only something he "would like to see", you may not have to do anything.
Would you be chancing damage to wire already in the conduit by granting his wish? Might be better to allow the conduit as the ground.
Family.....They're always there when they need you.
Edited 5/13/2009 8:33 am ET by MSA1
Would you be chancing damage to wire already in the conduit by granting his wish? Might be better to allow the conduit as the ground.@@@They were not about to sign until a new ground was there.The ToolBear
"You can't save the Earth unless you are willing to make other people sacrifice." Dogbert
why not add another conduit with just a ground wire
Another conduit with ground...@@@Thought of that option. Would have been a desperation move. Get inspector to sign off. Across closet, blow thru stucco, LB, run along fascia, LB, run down wall, blow thru stucco in the doghouse, fiddle around inside, see about getting it into the breaker box, etc. If there was a way to pull in the FMC, that would be the choice. And it worked.Meanwhile, he signed off on the rough electrical today, so on to other adventures. Like insulation. Like: Gee, you need a 2" drain for that shower/tub. Not back when. All these units have 1.5" drains for their shower/tubs. What are we supposed to do, rebuilt the whole eight units, then move on to the next set of buildings? The ToolBear
"You can't save the Earth unless you are willing to make other people sacrifice." Dogbert
I'd pull out the old wire and then add the new line to it and pull it all back through again.
I refuse to accept that there are limitations to what we can accomplish. Pete Draganic
Take life as a test and shoot for a better score each day. Matt Garcia
I'd leave the wire and change the raceway.
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That was my 1st thought. To risk abrading off the insulation on another lead is very possible. All it take is a little moisture or touch the conduit and would short out.
That is were I choose pulling all out, inspecting and reusing if condition warrents it. If not, replace the damage or all wires. 200ft of #6 is not that much $$$ compared to the potential of call backs and the costs(liabilities) associated with it.
somebody mentioned pulling in the direction of the spiral on flex is only learned by trial and duhhh! And my wife says I never admit when I make a mistake.