Telephone Wiring

Page 1 of 2  
While wiring in a new phone jack I got zapped. I measured 55vots accross b&y zand R&G pairs.
I eventually went to outside telephone interface and plugged into test jack and found it coming from phone company.
There is no way this is normal is it?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You could add to that 90VAC when the phone rings.
Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for the fast response Bob. This is a constant 55 volts so it is not involved with the ring (and it is on both pairs anyway).
I had thought I had an old pricess transformer around but when I went out to the jack I was suprised.
Again: is this normal?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
yes
new wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Probably. Someone probably rang your phone at JUST the right time for you to get really ZAPPED. Either that or you were WELL grounded when touching the live wires.
Dialtone is -48-52VDC. I've never metered it at 55, but I suppose its possible. We VERY rarely disconnect a working pair before working on it.
You'll notice inside the S/NI/D it says something like [to avoid shock, you should disconnect the service prior to working on it]. Good advise, I guess.
--
:)
JR

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Why not? 60 volts at idle, 90 volts at ring.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
new wrote:

AC or DC?
Were you using a digital or analog meter?
Do your phones work OK?
Most standard phone lines are 48 volts DC with no phones on that line "off hook".
I wouldn't worry much about measuring 55 volts.
You can feel a shock from much lower voltages, particularly if something like the sharp end of a wire drags through the dry outer layer of your skin.
HTH,
Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
An analog meter and AC voltage.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
new wrote:

Well, you will only have AC voltage on a phone line during a "ring", but even though your meter is set to measure AC it will probably still give you a reasonably accurate reading from DC voltages.
Anyway, I think enough folks have responded to assure you that what you measured is normal enough.
Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
new wrote:

Yes, normal and expected.
In the US while the line is idle one of the pair is at approx. ground, and the other at approx. -48V DC.
Ring voltage is a 20Hz sine-wave of 90VAC on the -48V line (peak V is 90-48, or +42V, and -peak is -48 -90 or -138V).
Dave
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
new wrote:

As others have said, voltage sounds about right. But you shouldn't feel it under normal circumstances. You will get quite the jolt sometimes if the phone rings while you are playing witht he wires.
You have voltage on both sets of wires. Do you have 2 lines coming in to the house?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Heh. For reasons I won't go into here, I had to splice a telephone line while sitting on a concrete floor in our detached garage, and I was too lazy to sling something non-conductive underneath me.
That _hurt_. Even without ringing. Was unable to grasp/twist the wire.
The SO could hear me swearing over 100' away in the house.
Finally gave up and sat on a piece of plywood.
--
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Chris Lewis wrote:

Huh. I always work on phones barehanded and never had a problem. Trying to remember if I've ever worked on them barefoot, too, but can't think of any time I did that. Never had a problem. Bared wires with a jacknife, pulled off cut insulation with my teeth, etc.
Maybe it's just me. My mother always said she wanted me to be well grounded, but I don't think this is what she meant.
What's the consensus. Do most people feel the voltage out of a phone or not?
BTW, my father (an electrician) always said that ringer voltage was esp. dangerous because it was close to the voltage of your heart. I don't have any idea if that is true or just an old wives tale.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Actually DC can be just as dangerous as AC. The heart muscle "clamps" instead of going into VF. If the current vector goes across the chest, it can be more dangerous than AC mains.
Yes, the "close to the voltage of the heart" is an old wive's tale (in fact I haven't ever heard that tale myself). The ion channels that produce the muscle contraction aren't working anywhere near telephone ringer voltage.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Agreed.
An electric chair uses DC somewhere in the neighborhood of 2,000-volts.
--
:)
JR

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 05 Sep 2006 21:58:50 -0500, Jim Redelfs

At one time "westinghouse" meant "electrocute"?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
unknown wrote:

I used to think it described a place where you went to "west" after a long day's work.
I remember the stories about the Edison (DC) and Westinghouse (AC) rivalry and how Edison argued that AC was more dangerous. Edison even went so far as to electrocute an elephant to support his case.
Don't watch this if you're an animal rights type:

http://www.youtube.com/watch?v=RnHXSL5jW-c&search
ison%20elephant
Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 06 Sep 2006 12:03:38 -0400, Jeff Wisnia

Sounds right. I remember when I didn't understand names well, and thought they were words. Some examples:
"Plymouth" is a disease you get from eating tires
"Douglas" ('dough glass') is a kind of plastic found in airplane windows
"Prestolock" (found on my mother's pressure cooker) means "press to lock"
"Fedders" (on an ice tray) means it's meant to be used to feed birds

I have a book that has a chapter about that. It's called "current wars".

BTW, Those who want to change 'dead' to 'fed' when describing Schrodinger's Cat.

I guess they're overloaded. That might explain how I have a (otherwise unused at this time) 4mbps connection and that downloaded at around 8Kbps.

--
110 days until the winter solstice celebration

Mark Lloyd
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mark Lloyd wrote:

Boy has this thread taken a weird twist. From telephones to electrocuting elephants. Who'd have thunk it.
Back then, they electrocuted elephants to prove they could. Now, they can't test shampoo on a rat. How the world has changed....
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.