ac voltage on ground start CO trunks 3

[strmwalker]

could someone tell me what nortel says is the maximum
voltage before you connected to the nortel pbx that
is acceptable voltage?i have a customer that has
copper trunks for local service CO trunks for outbound
and DID trunks which all of the trunks have hum on them
voltages are between 4.30 ac and 8.70 ac volts on the
demarc before you connected to pbx.



no problems only solutions

strmwalker

 

[acewarlock]

There shouldn't be any AC on the trunk, if there is call the Telco.




This is a Signature and not part of the answer, it appears on every reply.

This is an Analogy so don't take it personally as some have.

Why change the engine if all you need is to change the spark plugs.

 

[johnpoole]

it would be almost impossible to find any that have zero induction voltage.. it is filtered on the trunk card... 5 volts and below is common...

the question is after you dial, can you hear ac hum? both the provider and the switch try to block that... an idle line is going to induce... put 48 volt talk battery on that and voltages less then that are gone, filter out spikes above that and you can modulate the dc...

if you have ac hum on a butt set infront of the switch.. report it and have a miliwatt test ran... they can get better then the posted voltage, but they will not unless you force the issue.. i've seen as high as 12 vac on a rural 1fb line without customer complaints... (no i didn't work on it)...

john poole
bellsouth business
columbia,sc

 

[PERRYPJ]

How far outside bumf are you, that cable has to follow the power lines for quit a few miles to pickup any iduction

OLD ROLMEN WORKING ON NORTELS

 

[strmwalker]

well so be it i went out to the customer site today
i open the locals cable box took the pair feeding
yhe 66 block that i connect the trunks to yes i said
66 block not rj21x like it is suppose to be and to
the x connect wire off 4 0 0 0 my tn .now picture
this no cross connect on 66 block the other end of
this cable going in to the local cable terminal 20
feet max disconnected the pair meaning unscrewed from
the terminal flapping in the breeze i read 30 volts
ac tip to ground and 30 volts ac ring to ground.on
the locals cable pair going back to the central office
ihave 8.70 volts ac cross tip and ring .dialed silent
termination back to co ran noise and power induction
test all in the red no good on my old t137 test meter
and the same on my new 965 meter.am i missing something
here or does the problem point back to the local telco.
oh i also found 28 volts ac on the ground wire feeding
their fiber why ground glass?but you should not have ac volts on a ground wire.

no problems only solutions

strmwalker

 

[acewarlock]

Sounds like a very Bad Ground.




This is a Signature and not part of the answer, it appears on every reply.

This is an Analogy so don't take it personally as some have.

Why change the engine if all you need is to change the spark plugs.

 

[PERRYPJ]

The ac voltage to ground on each side doesn't really matter as long as it reads the same, the pair is balanced. The ac voltage across tip and ring should be there. And yes they put a ground wire on fiber, because years ago when it first started to go in there was no ground wire on the cable. Guess what, when you cut a cable without a gound you have no way of telling where it was cut.

OLD ROLMEN WORKING ON NORTELS

 

[PERRYPJ]

Sorry the above answer should read should NOT be there

I've used the 137 and they don't lie, I would get your Telco out there and show them what you found.

OLD ROLMEN WORKING ON NORTELS

 

[strmwalker]

hey guys thanks for yhe input i just was thinking in was
going crazy.johnpoole thanks alots.acewarlock thanks,
PERRYPJ i think us old rolmens learned to use the 137
because the telco did not believe us when we reported
troubles thanks guy.

no problems only solutions

strmwalker

 

[MagnaRGP]

Also the glass is grounded because it can cause static electricity.