 brassy
join:2004-01-09
Brantford, ON | Fairly powerful shock from touching green line Is this normal?
I was rewiring, and the green line was giving quite an awful shock. It forced me to drop it and jump back a little.
I have done some phone work before, and never experienced anything like this.
What would it be a sign of? if anything? |
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 sbrookPremium,Mod
join:2001-12-14
Ottawa
kudos:4 | No, it's not normal. What else were you touching?
Normally you'll only get a significant shock if ringing is being applied to your line. |
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 KeithWhy Ask Than?Premium
join:2002-10-28
Fort Erie, ON | reply to brassy
said by brassy:What would it be a sign of? if anything? 2 things come to mind
1) ring ring
2)it's a sign you should not work on your phone line:) |
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 DKSDamn Kidney StonesPremium,ExMod 2002
join:2001-03-22
Owen Sound, ON
kudos:2 | reply to brassy
The phone was ringing. The green wire is the ring. Red is tip. Ring voltage is between 70 and 90 volts DC.
Either that or your brain rebooted... |
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brassy
join:2004-01-09
Brantford, ON
1 edit | Theres just no way the phone was ringing though. I had a cordless one (connected to another jack) and it didnt ring.
I think im just going to stay away from that line. 
The only thing I would be touching would be the plastic phone jack. |
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DKSDamn Kidney StonesPremium,ExMod 2002
join:2001-03-22
Owen Sound, ON
kudos:2 | Or you have a bad Bell ground. |
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| reply to brassy
said by brassy:Theres just no way the phone was ringing though. I had a cordless one (connected to another jack) and it didnt ring. You did not hear it cause you rang instead. |
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 joshbDon't sweat the small stuff.Premium
join:2006-03-04
Calgary, AB
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| reply to brassy
said by brassy:Theres just no way the phone was ringing though. I had a cordless one (connected to another jack) and it didnt ring. Did it feel good? 
On a side note you probably have a bad ground on bell's side. Even with that kind of voltage going through your body you would have known after the fact if it had rang on yah. Well as long your had voice mail and the person left a message that is.
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If things made sense in life there would be no challenge in life. |
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| The phone line has 48 volts on it when on hook, but if you touch one side and either you are a good path to ground or another part of your body is touching another wire, metal structure, waterpipe, etc you will get a small usually harmless jolt. I think most of the jolt is from the unexpectiveness of receiving the jolt. |
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sbrookPremium,Mod
join:2001-12-14
Ottawa
kudos:4 Reviews:
·TekSavvy Cable
·Rogers Hi-Speed
1 edit | reply to DKS
said by DKS:Ring voltage is between 70 and 90 volts DC. I hope not or the clapper in an old bell would hit one of the gongs and stay there! Ring in N. Am. phones is nominally 88V AC 20Hz superimposed on the 48V supervisory standing voltage between Red and Green. (For the UK, that's 60-75V AC 25Hz)
OP ...
You can't have gotten a shock from touching the green wire alone. You had to be touching something else, AND you had to have fairly moist fingers to get a significant belt from the supervisory voltage only. Having worked on old strowger exchanges, the 48V supervisory voltage is enough to "bite" when shocked with dry hands, but not to kick. It takes ringing to do that! |
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DKSDamn Kidney StonesPremium,ExMod 2002
join:2001-03-22
Owen Sound, ON
kudos:2 | You did the same search I did.  |
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sbrookPremium,Mod
join:2001-12-14
Ottawa
kudos:4 | Yeah, except that the guy who wrote the original got it wrong too ... he had the frequency at 25Hz, which for MOST old bell phones was too fast for the clapper! |
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| your line isn't probably grounded. |
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| Most of the time the inside wire is not grounded. |
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| reply to DKS
said by DKS:The phone was ringing. The green wire is the ring. Red is tip. Ring voltage is between 70 and 90 volts DC. Either that or your brain rebooted... RED is the ring on inside wire(quad)green is tip and normally the ground side but the polarity obviously got reversed somewhere. and he must have been grounded causing the shock(shock happens)no big deal, no reason to get scared of playing with phone wires |
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sbrookPremium,Mod
join:2001-12-14
Ottawa
kudos:4 | There is no ground side ... red and green are both offset to ground under normal circumstances. Otherwise party lines and other requirements for ground offset signalling such as "message" would never have worked. |
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| if you put an ohms meter on the ground side it will show a ground
ring shows voltage |
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| Sometimes... |
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 LazManPremium
join:2003-03-26
canada | reply to BTS Niagara
If either side of the pair is dead-shorted to ground, you'll get a BAD hum on the line...
As has been said, nominal voltage in North America is -48vdc. Ring current, on a standard 1FL is between 60-110vAC at 20Hz.
As for 'ground' on the one side - you'll be seeing 0v differential to ground; that's not the same thing as being grounded...
Anyways - it's possible, espically in this humid weather, to get a shock from the voltage on the line - although it's more of an annoyance then painful. The sweating we're all doing right now increases the skins conductance, and allows the lower voltage/current to pass thru the body. Ring current, is painful!
Laz |
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sbrookPremium,Mod
join:2001-12-14
Ottawa
kudos:4 Reviews:
·TekSavvy Cable
·Rogers Hi-Speed
| You want the belts you get from old strowger equipment ... even though you're only switching 48V to get the ring, because of all the inductors on the line, you get very high spikes on every ring pulse. We checked it with an scope and found up to 400V spikes on every cycle, measured by a true RMS meter, the result was closer to 55V ... but that kicked! |
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