Reversed Phone Line???

[Steph in PA]

Hi, I have two problems:

1) I bought one of those telephone line testers made by GB Instruments for $5. I plugged it in, and it came out as "red", which means "reversed line". What does this mean?

I checked at the NID (the part inside the house), and only a red and green line are connected there, with the yellow and black not connected and being wrapped around the green and red; but my phone works fine.

BTW, I'm furious that the yellow and black wires are not connected, since I am getting a second phone line in the next few months. Why would someone install the phone line this way? Is this normally how the pros do it?

2) My other telephone jack in the house is testing as "dead", since no light lights up on the tester. I checked at the NID in the house again, and the red and green wires are connected there. I traced the line about half way, in the basement, and it appeared to be ok. The other half was inaccessible, since the landlord has about 1-2 feet of books, newspapers, magazines, etc. piled on the entire floor, which is blocking my access to the part of the basement where the line runs.

Does anyone know why my phone jack is reading dead? I haven't check the actual jack yet.

Thanks!

[Steph in PA]

I'm pissed because now I have to go back and repair someone's shoddy work. I wish I could bill someone for this.

[Steph in PA]

Do I need to disconnect the phone line at the NID outside the house before I connect the yellow and black lines? The problem is there are two NID's, one on each side of the house, with one being connected to the other via a line that runs through the basement (there are three apartments in the house and it looks like one NID was added late?)! And I can't get one open, and the other just looks like a gray blob, half the size of the one I can't get open.

Phone lines don't carry much voltage, do they?? So I don't need to worry about geting shocked, especially if I use insulated screwdrivers???

Another thing is that it appears one of the phone lines leads to a door bell ringer!!

[PrecisionMachinisT]

Hardly any current...

Still, it will ring your chimes if someone happens to call you while your there working on it.

~95 volts on incoming ring, IIRC....

If they all show reversed, suggest just swap wires at the nid box.

BTW :

Nobody but a hack uses red green yellow black anymore on new installs anymore.

[Rick Slater]

[William W. Plummer]

Black and Yellow are to be used for a second line. You can purchase line splitters.

Polarity reversal is how the determine whether you have a pulse dialing system or a tone dialing.

[Doug Miller]

It means that the red and green wires are reversed somewhere between the demarc box and the outlet.

That's because modern telephones need only the red and green.

Yes, that is the way it's normally done, when installing a single phone line, since only the red and green are needed. Calm down, take a deep breath, and connect the yellow and black wires as well.

Problem's in the other half, then. Probably. It's not unheard-of for there to be a break inside the cable insulation, where it isn't visible.

I guess it must be pretty hard to move that stuff, huh?

It's reading dead because isn't connected. There may be a break in the cable somewhere, or one or both of the wires to that jack may not be connected to the jack, or to whatever point they come from to supply that jack. Check the connections at each end first. If both red and green are connected properly, then check the entire length of the cable for damage, and repair or replace as necessary.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[Doug Miller]

Take a deep breath. It's not shoddy work. It's a perfectly normal single-line installation.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[BocesLib]

Hardly any current???? Hold the lines and wait for it to ring. you'll feel that one!

[Doug Miller]

It's somewhere around 95 VAC, but the current is indeed very low.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[Art Todesco]

Wrong! You can pulse dial or touch tone on any line. The receiver in the central office takes either. The telephone central office can, via software, not allow touch tones for those who don't pay the extra fee although I think today, it's mostly included. But, if you can touch tone dial on a line, you most certainly can dial pulse. Dial pulsing simply opens the loop a number of times as the dial returns (9 pulses for a number 9, etc.). Most modern telephone sets can work with the polarity reversed on a single party line. Older sets will work (it will ring, you can talk), but the touch tone dial won't put out tones when you press a button.

[PrecisionMachinisT]

The legacy POTS ringer is a classic example of a reactive AC circuit, and is very sensitive to line frequency.

[Philip Lewis]

or that it's reversed someplace before it even gets to the house Steph, did you test at the box?

Many modern phones will work with reverse wiring. Back in the early

80s i had a modem that would not work in one configuration, so I switched the polarity in the box. Afterwards, the phone would not produce the tones for dialing... so i had to tap them out using the hook.

unless they're two line.

I know I don't make a habit of messing with other people's things. Heck, I don't like going into my wife's purse when she *asks* me to.

[Chris Lewis]

According to Doug Miller :

Voltage even when it doesn't ring, is high enough to ring your chimes if you're well-enough grounded.

[I tried to splice a phone line while sitting on a concrete floor. I found that I couldn't. So I had to stand up ;-) ]

[HorneTD]

Sorry Art but you are the one that is wrong. When touch tone dialing was first provided on subscriber lines polarity was how the use of TT was limited to those who paid for it. The old 500 desk sets and similar phones of that error had polarity specific touch pads. The polarity of the line was reversed at the protector to prevent the use of touch tone telephones on lines that had not paid the fee. Many residential premises have reversed polarity on the internal wiring as a legacy of that original practice.

-- Tom H

[Chris Lewis]

According to HorneTD :

Some undoubtably worked that way.

Others didn't - it depends on the switch and telco. Some switches you simply enabled/disabled tone on a line-by-line basis.

[We make telco switches (ie: DMS) that do that ;-)]

Line polarity was (like 30 years ago) also apparently used for a simplified "2 customer" party line scheme. Where, instead of distinctive ring, the ring was transmitted down the line in just one polarity, and only the phone with the diode the right way around "heard it". My grandparents had that at a cottage, and so apparently did my inlaws for a time.

Aside from these prehistoric setups, these days it rarely matters which way around tip/ring, red/green are. Better to have it the right way around, but...

[Art Todesco]

Tom, you may be right for some electromechanical offices, however, ever since the

1ESS system (AT&T-Western Electric) came out in the mid 60s, it was a software controlled add on feature. But, even in the electromechanical offices, step by step and crossbar No.1 and No. 5, there were line groups that could or could not access touch tone receivers. I don't know about non "Bell" offices.

[Matt]

My 1A2 KSU and keyset station arrived today....

Once the punchdown tool gets here, I get to choose between 25 pairs of wires to connect backwards!

[HorneTD]

Since ringing current is 20 HRZ AC that would not work. What was commonly done in early practice was to connect the ringer between the earth and one side of the line. In that way the ringing current could be sent on tip or ring depending on which party had been called. That system of ground return ringing was used on multi party lines so that only half the subscribers would have to hear each ring signal.

-- Tom Horne

[HorneTD]

Yes and the polarity was reversed at the protector when the subscribers status changed to dial pulse only after the number was assigned to them.

-- Tom Horne