Measuring lenghts of feeders

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ohmhead

Senior Member
Location
ORLANDO FLA
Well question how many of us electricians out there use measuring tape True Tape or Mule Tape for measuring conduit feeders ?

What does a roll cost you do you think its high priced ?

Whats you best brand ?

Do you use it over and over again ?

Does your crew or helper try to use that first 100 foot over and over again meaning to save it as long as possible and save on the math ?

If you vaccum it in underground what issues do you have meaning do you leave it in until you pull your string in at a later date or do you install a string or polyline then measure your length of conduit and reuse it over and over .

How accurate is it and do you add for 90 deg elbows or offsets ?

Do you add for slack ?

Just some questions that one electrician to another as i would like to know how other areas of our electrical world measure .


Who do you trust to measure and how do you control your commercial work on lots of runs as copper is not cheap?
 
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iwire

Moderator
Staff member
Location
Massachusetts
Well question how many of us electricians out there use measuring tape True Tape or Mule Tape for measuring conduit feeders ?

Use true tape 99% of the time, mule tape only when specified.

What does a roll cost you do you think its high priced ?


No idea, I have been told Mule tape is expensive.


Do you use it over and over again ?

I have reused Mule tape not true tape.

Does your crew or helper try to use that first 100 foot over and over again meaning to save it as long as possible and save on the math ?

Nope

If you vaccum it in underground what issues do you have meaning do you leave it in until you pull your string in at a later date or do you install a string or polyline then measure your length of conduit and reuse it over and over .

The true tape stays in until we are ready to pull.



How accurate is it and do you add for 90 deg elbows or offsets ?

I follow the instructions on the roll for bends.

Do you add for slack ?

Not sure what you mean, I measure close.

Who do you trust to measure and how do you control your commercial work on lots of runs as copper is not cheap?

I have never run a job so big I did not do the measurements for expensive pulls myself. Multiple parallel sets are a killer, each 1' of slack added on 32 conductors at $3.00 per ft adds up fast. Of course coming up short is entirely unacceptable.
 

ohmhead

Senior Member
Location
ORLANDO FLA
Well iwire when you say you leave it in conduit how long before you pull your feeders is it laying in conduit a week or months ?

Let me ask a question if say Harry the electrician had say 80 runs out of multiple transformers to job service in building lets say paralleled conduits meaning say 10 runs in a single gear main and 10 in each of the 7 others would you measure each of the conduit runs in that gear to that transformer one by one ?

Or do you think most electricians would measure the longest run of the group in that single switchgear and call it a day if they did the underground and had known which is which meaning the longest run in each of the switchboards to transformers ?

Generally what do you think the x group of electricians would do measure each conduit or just the longest of that group of parallels of 10 in each switchboard .
 
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wawireguy

Senior Member
True tape works well but with PVC I don't like to leave it in the conduit. Sticks to the sides and can be difficult to pull out. Course I'm talking about long runs with the full amount of bends or more in them. What is it with some electricians thinking that 360 degrees doesn't count because it's PVC. Using a measuring tape is not high priced compared to coming up short or to long.
 

ohmhead

Senior Member
Location
ORLANDO FLA
True tape works well but with PVC I don't like to leave it in the conduit. Sticks to the sides and can be difficult to pull out. Course I'm talking about long runs with the full amount of bends or more in them. What is it with some electricians thinking that 360 degrees doesn't count because it's PVC. Using a measuring tape is not high priced compared to coming up short or to long.


Well i highly agree with the drag and stick comment we use lots of PVC underground and the water & sand dirt in conduit its like a suction cup .

But lots of people are not aware of the real issue when you glue it together the glue drips down inside that coupling but does not drop completely it hangs in the air and drys only on the outer skin .

Its still wet on the inside so if you blow a tape in or vaccum in one your smearing that glue on the tape and when it does dry its not easy to pull out sometimes we cant get it out so we blow passed it and when we pull in a run of 600mcm it comes out with the head when it pops out its one bigg ball of true tape .

You sound like you have pulled in a few ?"
 

Rockyd

Senior Member
Location
Nevada
Occupation
Retired after 40 years as an electrician.
I have never run a job so big I did not do the measurements for expensive pulls myself. Multiple parallel sets are a killer, each 1' of slack added on 32 conductors at $3.00 per ft adds up fast. Of course coming up short is entirely unacceptable.

It works different on a big project - you have to trust your leadership upstream, as well as downstream. When that is "out of whack" so to will your project be.

Have to seperate the wheat from the chaff.


Edit: We will be pulling in a few miles of wire starting after the new year!:D
 
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infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
We use true tape, measure bushing to bushing and add on accordingly to perform the terminations. On big pulls we typically will end up 15' or 20' extra when we're done. Many panels have the neutral at the bottom and the line at the top so you'll end up with alot of extra on the phase conductors. Better to have extra than not enough.
 

ohmhead

Senior Member
Location
ORLANDO FLA
It works different on a big project


Edit: We will be pulling in a few miles of wire starting after the new year!:D

Well thats kinda what we do on each project after we run all the underground we measure for weeks with only my best guys who know how to install a line and measure correctly.

Which they sign on the line !

As stated above we also measure end of conduit to end of conduit then we add per each termination in each gear or panel or transformer or MCC and then order in bulk multiple runs of same size wire on spools we use a spread sheet and number the spools and list the[ from and to] locations .

Meaning we have a spread sheet feeder list of say 300 runs[ to and from ]with[ room number & location ] [ panel name] [ wire size] [ conduit size & type ] [ length of run one way] [voltage & phase] [ground wire size] [cu or alu ].

We also use this to summit list for engineer to do a cor/ fault study .

Each spool has a number on it from the factory and its taken off the trucks and stored in groups of first pulls to last pulls by number on spool .

We know how much is left on spools buy which pull was done and which one was not pulled .
Yes trust in your people is most important .
 
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iwire

Moderator
Staff member
Location
Massachusetts
i agree with infinity's post, our company pulls the same way. Always measure with lots of slack. Add it into the bid cause u will be surprised when u need just a five or ten foot piece of wire

Oh include it in the bid, but when I measure it I wan to beat the bid.
 

ohmhead

Senior Member
Location
ORLANDO FLA
Well we agree iwire we must beat the take off on wire length thats lots of dollars on most of our jobs.

Its a thing with the bean counters they cant seem to measure at angles they always think conduit runs square on the drawnings i guess its easyer to draw on paper but in the field we take it straight so money is made on every job .

Now there is rabbit but its sold to the scrap yard we add one foot for each 90 elbow and we add a little for bends or make up .

But its measured no guessing .
 

Karl H

Senior Member
Location
San Diego,CA
On long runs I'm a Tru-tape fan. When it comes to PVC underground
I pull the tape out with a rope attached. I've had a few occasions
where the glue adhered to the Tru-tape and was very difficult to pull
out. Figuring out the slack and make- up length is a science that is best
left to experience or throw yourself to the "Wolves" better known as
"Trial and ERROR.":)
 

ohmhead

Senior Member
Location
ORLANDO FLA
On long runs I'm a Tru-tape fan. When it comes to PVC underground
I pull the tape out with a rope attached. I've had a few occasions
where the glue adhered to the Tru-tape and was very difficult to pull
out. Figuring out the slack and make- up length is a science that is best
left to experience or throw yourself to the "Wolves" better known as
"Trial and ERROR.":)
\

Well Karl thanks for the input let me ask this question the true tape you use what brand or type ?

As you say you pull out the rope on long runs with the true tape so iam assuming its not your 1/4 wide standard greenlee tape ?

Over the years we have found that the smaller true tape not only sticks but it breaks if you try to pull out a small 1/4 " rope on long pulls .

Also we have found that on long runs lets say 500 foot and up it doesnt vaccum very good as it sticks but if you try to blow it with a compressor it sticks and can ball up inside conduit as its very thin and easy to tangle have you every had that happen ?

Meaning it kinda runs passed itself when it sticks inside the walls so your measured length can be off by what ever .

Thanks for the help Karl
 

Mike01

Senior Member
Location
MidWest
measurement of existing......

measurement of existing......

so if how do you meaure the length of the cable that has already been pulled? Just curious. if the cables are installed is there a way to disconnect them and measure the lenght of the cables??
 

ohmhead

Senior Member
Location
ORLANDO FLA
so if how do you meaure the length of the cable that has already been pulled? Just curious. if the cables are installed is there a way to disconnect them and measure the lenght of the cables??

Well you can buy one from greenlee if you have 800 plus dollars but its not as accurate as one may think.

Heres why we have them at our tool crib we do a lot of checking cable lengths on our scrap wire reels to reuse at the end of a project or to send to another project mostly 500 mcm and larger .

If batterys are at 100 % your fine but when they get to 70% your going to get a error and can be 10 foot or more .

Meaning whos helper is going to look at the batterys if the display is working you would not know it was not going to work ?

If the temp of the wire is at 70 deg your fine but higher or lower and its not accurate and also the connection with the cable clamps better be clean and solid or you get odd readings .

How do we know this we use them on every project as we pull lots of wire and cables on each project and there part of our tools .

You could make your own we have a homemade current injector at work which injects 1 volt at 1 amp thur anything put a volt meter across anything with this injector and you have real ohms the actual ohms of a wire at any length .
 
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wawireguy

Senior Member
I don't like blowing in true tape myself. Rather blow in a poly line then pull in the tape then yank the poly back.
 

ohmhead

Senior Member
Location
ORLANDO FLA
I don't like blowing in true tape myself. Rather blow in a poly line then pull in the tape then yank the poly back.

Well i would like to ask you this wawireguy but first your the only person who does it like we do it .

Our company uses true tape the greenlee 1/4 wide not mule tape .
The reason is money mule tape is a waste of money .

We do not ever install true tape first .

We shoot with a 120 lb air compressor a rat made of 2 rags and duct tape & bisqueen this will fly thur any conduit any length with polyline .

Next we tie on the true tape and measure then we pull the true tape back out and reuse until it looks like its done .

Heres why true tape sticks and hardly never comes out after a day or two .
If you blow true tape in it will blow apart or ball up inside and it can over lap inside conduit.

We do hundreds of hundreds of conduits not just one or two on each project the cost to leave it in would be costly plus after we get our wire that takes 3 months its never coming out ever .

Were only talking underground conduit not overhead

Does this sound like you projects ?
 
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