Electrical question

Status
Not open for further replies.

electricalist

Senior Member
Location
dallas tx
Read and note the part of the print legend that is legible downstairs on each wire.
Read and note the part of the print legend that is legible upstairs on each wire.

Look up the full print legend text from the manufacturer's datasheet. All wires should have the same number of letters difference from their downstairs wording to their upstairs wording, within this full text. Because all wires in the conduit are the same length.

Rearrange the lists, until the differences in wording on the print legends are all equal, between the wires that you think correspond.
This was kinda my first thought.
Mark each wire down stairs at a equal place then go upstairs and do the same. Then pull one wire at a time making the marks staggered. The longest wire upstairs should be the marked shortest downstairs.
Or just pull them all out.
 

Smart $

Esteemed Member
Location
Ohio
This was kinda my first thought.
Mark each wire down stairs at a equal place then go upstairs and do the same. Then pull one wire at a time making the marks staggered. The longest wire upstairs should be the marked shortest downstairs.
Or just pull them all out.
Assuming a straight vertical run, there has to be something holding them up or they'd just fall out. To remove or undo what's holding them up requires you to go upstairs....
 

Smart $

Esteemed Member
Location
Ohio
Read and note the part of the print legend that is legible downstairs on each wire.
Read and note the part of the print legend that is legible upstairs on each wire.

Look up the full print legend text from the manufacturer's datasheet. All wires should have the same number of letters difference from their downstairs wording to their upstairs wording, within this full text. Because all wires in the conduit are the same length.

Rearrange the lists, until the differences in wording on the print legends are all equal, between the wires that you think correspond.
And then there's an off chance that two or more are the same or close enough to make you wonder. You can use pairing and ohmmeter to ascertain.
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
Assuming all 11 conductors have no shorts and you have a low-resistance ohmmeter, on first floor wirenut 5 pair, leaving one with no connection.
.....
Wash, rinse, repeat for the remaining wires.

*Process is a little longer using continuity, but uses a similar procedure.
Absloutely brilliant. They are just ignoring you cause you figured it out.

ice
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
There might be a way, but I've been side tracked by honey-dos and couldn't finish it. I'll get back to it tonight to prove it out. But it will assume you make one trip for the discovery process, then a second trip to actually make up the leads at the 3rd floor. Is that allowed?
 

electricalist

Senior Member
Location
dallas tx
One trip up stairs and an ohm meter no continuity marker and tape.
So the method has to be resolved on the first floor. The answer is in the wording. It doesn't say ring out 1 nor does it say each,,just ring out the wires.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
Ok, i think i got it. There is no way to do this with only ONE trip upstairs, unless you don't count the trip you make AFTER you succeed. So accepting that premise, here"s how.

Starting at floor 1, tie 5 pairs of the wires together, number each par as 1-5 with the tape, you will have one remaining wire. Attach it to ground.

Go upstairs (trip 1) to floor 3 and test ohms between all wires and to ground, identifying each pair by the fact that there is continuity and marking them with tape. The one that reads to ground is wire #11, mark it. Now tie the 5 pairs together in a series string.

Go back down to Floor 1. Remove a connection of a pair of wires and measure oms between them, if there is still resistance just reconnect them and try a different pair. Repeat until you find one wire that measures infinity compared to any other wire, that is wire #10, mark it. Repeat breaking any pair and when you find the one with no continuity, mark it #9, repeat until you are down to the last pair, those mark as 1 and 2. You now have all wires identified at floor 1 and ready to be used at floor 3. While still at floor 1, now tie them together in series, but since they are numbered, be VERY specific about the sequence being 1, 2 , 3, 4, 5... 10.

Go back to floor 3 and connect wire #11 to one end of your series string up there, sp now you only have one end tp check measure the resistance of the entire string and record it. Then begin removing wire connections one at a time and testing the resistance on each one compared to ground. When you find one that is no longer continuous to ground, record the resistance on the side NOT going to ground. Mark it with the resistance value, reconnect it and repeat the process with another set in the series string, each time breaking the chain and recoding the resistance of the ungrounded side and marking it on that wire, then reconnecting it. When you are done, the wire with the LOWEST resistance is #1, the next lowest is #2, the next lowest after that is #3 etc. etc. you are ow ready to connect and use those wires at floor 3, knowing what the numbers are when you return to floor one.

PS:
Aw crap! This sat on my iPad all day while I was doing chores, then I worked it out on paper to prove it, posted it, and saw afterward that Smart$ had beat me to it by a mile! He also used less words to describe it... He wins!
 

Besoeker

Senior Member
Location
UK
Enough conductors to have bulk and friction hold 'em up would be well over the fill limit. :happyyes:
You may well be right. Perhaps the conductors to touch the conduit wall anywhere on the run so there would be no friction.
 

Besoeker

Senior Member
Location
UK
You may well be right. Perhaps the conductors to touch the conduit wall anywhere on the run so there would be no friction.
Let me post that again.
Perhaps the conductors don't touch the conduit wall anywhere on the run so there would be no friction.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Relax. You got it. You gave enough information to figure out how to do it with just continuity

ice

I don't see how you can tell which pair of conductors is which in this way.

All you can tell is there are five pair of conductors upstairs. You cannot tell which individual wire in a pair goes where because you can't tell which pair is which upstairs. All you can do is determine which wires are paired together.

I think a variant of this might work by connecting pairs together at the first floor and then wiring pairs in series upstairs along with the single cable. That would give you an open end to start with that is identifiable.
 
Last edited:

kwired

Electron manager
Location
NE Nebraska
A few years ago now I was talking to delivery man from one of my supply houses. He had a reel of larger copper wire on the truck (maybe 3/0). After I made some general comment about it he explained he was taking it back - was originally sold to a POCO. Their main use of larger sized 600 volt insulated conductors is for runs from a meter socket up the pole for connection to either transformer bank or overhead wiring methods.He said they don't like the super slick conductors that many wire and cable companies now have (like Sim-Pull, though I believe this one was from another company) as they like to fall down the raceway much easier then the standard conductors do. I have noticed this a little myself at times, so there must be enough friction to make some difference in a vertical run, plus the longer the vertical run the more conductor weight, the more tendency it will have to pull itself down. With small conductors you may also find that solid conductors will not "fall out" of a vertical run as easily as stranded conductors do.
 

Smart $

Esteemed Member
Location
Ohio
I don't see how you can tell which pair of conductors is which in this way.

All you can tell is there are five pair of conductors upstairs. You cannot tell which individual wire in a pair goes where because you can't tell which pair is which upstairs. All you can do is determine which wires are paired together.

I think a variant of this might work by connecting pairs together at the first floor and then wiring pairs in series upstairs along with the single cable. That would give you an open end to start with that is identifiable.
No need for a variant. You are exactly correct. You cannot tell which pair is which when you get upstairs... but you can tell which are paired and the one which is not. Then you cascade the connections and number them so you have a string of 11 segments when you go back downstairs.

Phase 1 downstairs
Phase 2a and 2b upstairs
Phase 3 downstairs

11%20conductor%20ringout.gif
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
Relax. You got it. You gave enough information to figure out how to do it with just continuity

I don't see how you can tell which pair of conductors is which in this way.

Following $S's lead, try this:
One has to pull and replace the downstairs a bunch of times

ice
 

Attachments

  • continuity.pdf
    27.7 KB · Views: 0
Status
Not open for further replies.
Top