Ok.....question for the thinkers. You have a plastic conduit run from the 1st floor to the 3rd floor of a building. You have (11) wires already in the conduit, all the same color and size. You can use an ohm meter, marker and tape. How can you ring out the wires making only one trip upstairs??
Electrical question
- Thread starter 203006549
- Start date
- Status
mgookin
Senior Member
- Location
- Fort Myers, FL
Leave your buddy downstairs as you go upstairs with a jumper.
YourElectricianOC
Member
- Location
- Orange County, CA
Use 9V batteries connected in series to give you 10 voltage taps (or 11 if you don't want to use the absence of voltage), and you only need one trip upstairs.
cadpoint
Senior Member
- Location
- Durham, NC
You could do it in two, buy five various size resistors wire them up to five pair labels
1 & 1 that get a resistor, leave one free go up stairs and ring out till you find five pairs, label accordingly 1a, 1b, etc. remove resistors.
Label free wire, then break all the "b's" and wire them together, go back down stairs and
ring out the five wires. mark one "1" as "1b".
1 & 1 that get a resistor, leave one free go up stairs and ring out till you find five pairs, label accordingly 1a, 1b, etc. remove resistors.
Label free wire, then break all the "b's" and wire them together, go back down stairs and
ring out the five wires. mark one "1" as "1b".
electricalist
Senior Member
- Location
- dallas tx
Is this by the hour ?
electricalist
Senior Member
- Location
- dallas tx
pull 11 out identify them go up stair and push them back down.
cadpoint
Senior Member
- Location
- Durham, NC
Really, who pulls any same colors and not mark them ?
GerryB
Senior Member
- Location
- woodbridge, ct. USA
:lol:I say you got it!
electricalist
Senior Member
- Location
- dallas tx
Its probably not the answer, but if i walk in that building and thats all i brought. A Im not going up the stairs more than once . B Im not going up the stairs unless i have too.:happyno:
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
150228-2425 EST
Use 10 resistors of value R (possibly 500 ohms). Wire the resistors in series and at each end point and each node connect 1 wire. At the other end find the two wires with a resistance of 10*R. These are the end wires. Using one end wire you can identify all the other wires with the ohmmeter.
.
Use 10 resistors of value R (possibly 500 ohms). Wire the resistors in series and at each end point and each node connect 1 wire. At the other end find the two wires with a resistance of 10*R. These are the end wires. Using one end wire you can identify all the other wires with the ohmmeter.
.
- Occupation
- Licensed Electrician
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.
Go upstairs.
Using ohmmeter, find the one that has no resistance to others.
Mark it 1.
Find each first-floor pair.
Mark one 2 and 3, another 4 and 5, etc. up to 10 and 11. (NOTE: you can do this and the three preceding steps in one process)
Wirenut pairs upstairs 1 and 2, 3 and 4, 5 and 6, etc, leaving 11 isolated.
Go back downstairs.
Mark the unpaired wire 1.
Measure ohms between it and the inside of each wire nut.
Based on lowest to highest ohm reading, mark the wirenuts 2-3, 4-5, etc. up to 10-11.*
Disconnect 2-3 pair.
Ring out for 1 and 2 and verify no resistance to 3.
Mark 2 and 3 wires.
Reconnect 2-3.
Disconnect 4-5.
Ring out 1 and 4 and verify no resistance to 5.
Mark 4 and 5 wires.
Wash, rinse, repeat for the remaining wires.
*Process is a little longer using continuity, but uses a similar procedure.
BobChiz
Member
- Location
- Bayonet Point,Florida
tone generator?
kwired
Electron manager
- Location
- NE Nebraska
That would work, but not per the situation here where you only have yourself and items mentioned in OP.
kwired
Electron manager
- Location
- NE Nebraska
Only items listed, or can we have wire nuts, clip on jumpers, or similar items, as well as maybe a knife or strippers?
kwired
Electron manager
- Location
- NE Nebraska
I will also say impossible without some information about what is there before going up stairs, as I would waste at least one trip finding out what is there:happyyes:
Carultch
Senior Member
- Location
- Massachusetts
Buy 11 batteries, all of different voltages. You can invert polarities, so that you only need 6 different voltages. You can also use voltage divider arrangements of resistors, such that you can simulate battery voltages that do not exist.
Connect the negative terminal of each battery to the building steel.
Connect the positive terminal of each battery to each wire that you are interested in "ringing out".
Now go upstairs, measure the voltage on each wire relative to building steel, and that tells you which battery configuration it was connected to.
Carultch
Senior Member
- Location
- Massachusetts
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.
- Status