Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and
off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about to fail
and is drawing a huge amount of current at startup? How do you even measure
the inrush(?) current in such a case. Would pressing on the wire near the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

TKS

On 10/16/2015 04:29 PM, Texas Kingsnake wrote:
Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and
off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about to fail
and is drawing a huge amount of current at startup? How do you even measure
the inrush(?) current in such a case. Would pressing on the wire near the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

TKS





Yes, the power has to be OFF


....however... DO NOT FOOL with it . call a licensed electrician ASAP


Just tightening the connection is not going to be a fix as since there
was arcing, some burned wires and connectors will need to be replaced

On 10/16/2015 4:29 PM, Texas Kingsnake wrote:
Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and
off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about to fail
and is drawing a huge amount of current at startup? How do you even measure
the inrush(?) current in such a case. Would pressing on the wire near the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

Sounds quite plausible and yes, simply pushing on the wire could easily
have broken the point at which the arcing was happening.

It's certainly possible to just tighten the connection w/o cutting
power; I'd be much more comfortable going on if I had seen the actual
condition of the wire and connection before I just went on, however. If
it was actually arcing to that point, good chance there's some built up
corrosion and/or arc damage that should be taken care of.

Particularly if the external feed is Al instead of Cu, I'd not even
think of not doing the above, cleaning it all up well and replacing the
antioxidant.

--

On Friday, October 16, 2015 at 5:59:16 PM UTC-4, Texas Kingsnake wrote:
Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and
off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about to fail
and is drawing a huge amount of current at startup? How do you even measure
the inrush(?) current in such a case. Would pressing on the wire near the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

TKS

Not unusual for a loose connection to behave differently after you
push it or fiddle with it. It may just be temporarily making better
contact now. You can tighten it live, as long as you're 100% sure
you know what you're doing.

On 10/16/2015 05:12 PM, trader_4 wrote:
Onrcuit panel. Very strange.

TKS

Not unusual for a loose connection to behave differently after you
push it or fiddle with it. It may just be temporarily making better
contact now. You can tighten it live, as long as you're 100% sure
you know what you're doing.




If he was 100% sure of what he was doing he would not tighten it live.

also see my other replies

philo wrote:
On 10/16/2015 04:29 PM, Texas Kingsnake wrote:
Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit
breaker panel. When she turned the machine on I heard a loud buzz
from inside the box. Less than a second long. I had her turn the
machine off, took off the panel cover and watched as she turned the
machine back on. I saw arcing at the left-handed side of the panel
at the point where the heavy black cable from the street enters the
box. I had her turn the machine on and off and it happened again. Then
I pushed the black wire right where it enters the clamp and it
hasn't happened again, despite having all the same lights and
appliances on. I am thinking the clamp has loosened over time. I am
going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am
going to try to tighten the clamp which may have not been tightened
in 40 years. Does the power *really* need to be killed at the meterhead?
I've
changed out breakers without killing main power (so much frikkin'
stuff needs to be reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about
to fail and is drawing a huge amount of current at startup? How do
you even measure the inrush(?) current in such a case. Would
pressing on the wire near the clamp cure it temporarily or is some
other process in play? What would account for it happening twice and then
not happening
again. The only real intervening act was to push on the wire jacket
at the point it enters the clamp on the circuit panel. Very strange.

TKS





Yes, the power has to be OFF


...however... DO NOT FOOL with it . call a licensed electrician
ASAP

Just tightening the connection is not going to be a fix as since there
was arcing, some burned wires and connectors will need to be replaced

Really ? Without seeing the situation you are going to tell this guy stuff
needs to be replaced ? I go along with have a licensed electrician check it
, since the OP doesn't seem to understand how serious this *COULD* be , but
it could also be as simple as tightening the screw and walking away .

--
Snag

On 10/16/2015 05:10 PM, dpb wrote:
On 10/16/2015 4:29 PM, Texas Kingsnake wrote:
Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside
the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw
arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and
off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the
same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am
going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs
to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about
to fail
and is drawing a huge amount of current at startup? How do you even
measure
the inrush(?) current in such a case. Would pressing on the wire near
the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening
again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

Sounds quite plausible and yes, simply pushing on the wire could easily
have broken the point at which the arcing was happening.

It's certainly possible to just tighten the connection w/o cutting
power; I'd be much more comfortable going on if I had seen the actual
condition of the wire and connection before I just went on, however. If
it was actually arcing to that point, good chance there's some built up
corrosion and/or arc damage that should be taken care of.

Particularly if the external feed is Al instead of Cu, I'd not even
think of not doing the above, cleaning it all up well and replacing the
antioxidant.

--



I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.


Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

On 10/16/2015 05:21 PM, Terry Coombs wrote:
philo wrote:
On 10/16/2015 04:29 PM, Texas Kingsnake wrote:
Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit
breaker panel. When she turned the machine on I heard a loud buzz
from inside the box. Less than a second long. I had her turn the
machine off, took off the panel cover and watched as she turned the
machine back on. I saw arcing at the left-handed side of the panel
at the point where the heavy black cable from the street enters the
box. I had her turn the machine on and off and it happened again. Then
I pushed the black wire right where it enters the clamp and it
hasn't happened again, despite having all the same lights and
appliances on. I am thinking the clamp has loosened over time. I am
going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am
going to try to tighten the clamp which may have not been tightened
in 40 years. Does the power *really* need to be killed at the meterhead?
I've
changed out breakers without killing main power (so much frikkin'
stuff needs to be reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about
to fail and is drawing a huge amount of current at startup? How do
you even measure the inrush(?) current in such a case. Would
pressing on the wire near the clamp cure it temporarily or is some
other process in play? What would account for it happening twice and then
not happening
again. The only real intervening act was to push on the wire jacket
at the point it enters the clamp on the circuit panel. Very strange.

TKS





Yes, the power has to be OFF


...however... DO NOT FOOL with it . call a licensed electrician
ASAP

Just tightening the connection is not going to be a fix as since there
was arcing, some burned wires and connectors will need to be replaced

Really ? Without seeing the situation you are going to tell this guy stuff
needs to be replaced ?


Yes, He said it arced. That means there is 100% chance burning of some
type has taken place.
I go along with have a licensed electrician check it
, since the OP doesn't seem to understand how serious this *COULD* be , but
it could also be as simple as tightening the screw and walking away .


That's how houses burn down...


I think all here agree that a qualified electrician should handle this.

On Friday, October 16, 2015 at 6:18:43 PM UTC-4, philo wrote:
On 10/16/2015 05:12 PM, trader_4 wrote:
Onrcuit panel. Very strange.

TKS

Not unusual for a loose connection to behave differently after you
push it or fiddle with it. It may just be temporarily making better
contact now. You can tighten it live, as long as you're 100% sure
you know what you're doing.




If he was 100% sure of what he was doing he would not tighten it live.

also see my other replies

Yeah, I agree with those of you that pointed out that if it's been arcing,
then it should be checked to see if it's damaged. I wasn't thinking
about what arcing that's been going on could have done.

On 10/16/2015 05:28 PM, trader_4 wrote:
On Friday, October 16, 2015 at 6:18:43 PM UTC-4, philo wrote:
On 10/16/2015 05:12 PM, trader_4 wrote:
Onrcuit panel. Very strange.

TKS

Not unusual for a loose connection to behave differently after you
push it or fiddle with it. It may just be temporarily making better
contact now. You can tighten it live, as long as you're 100% sure
you know what you're doing.




If he was 100% sure of what he was doing he would not tighten it live.

also see my other replies

Yeah, I agree with those of you that pointed out that if it's been arcing,
then it should be checked to see if it's damaged. I wasn't thinking
about what arcing that's been going on could have done.




For those who may have missed my posts over the past year or so, my
background is industrial batteries and I have repaired literally
thousands of chargers whose output is anywhere from 80 to 350 amps.


When I was still new on the job , if there was a burned or tarnished
connection, I'd typically wire brush it down then sand it until
everything was smooth and shiny.


It did not take me more than a year to realize that was only a temporary
fix as the connection would always go bad again.


Once copper is heated it actually goes through a chemical change and
becomes copper oxide. If the burned portion is cleaned, the copper still
has a tarnished look to it.


If you cut a new copper wire and compare it to a cut, tarnished wire you
will see the difference.


That's why I said all must be replaced.


If some hardware was replaced that ended up actually being OK, no harm done.

I think all see the corollary.

On 10/16/2015 5:21 PM, philo wrote:
....

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.

Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I don't know your scope of "high power circuitry" but I'm guessing it's
far more than a house feed. I've had very good success over the years
in doing so as long as the connector/wire haven't been severely damaged.

The key is first gotta look at what the situation really is, though, not
just assume tightening alone will be enough.

--

On 10/16/2015 05:48 PM, dpb wrote:
On 10/16/2015 5:21 PM, philo wrote:
...

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.

Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I don't know your scope of "high power circuitry" but I'm guessing it's
far more than a house feed. I've had very good success over the years
in doing so as long as the connector/wire haven't been severely damaged.

The key is first gotta look at what the situation really is, though, not
just assume tightening alone will be enough.



I worked with circuits 80 amps and above...which would come into the
range of a house power feed.

I do believe your statement however and assume it was just a very small
arc on a relatively low current circuit.


BTW: I found the picture of my socket wrench.

It was the day I decided that it would be OK to work on a live circuit
as long as I had my wrench all taped up.

I was 100% sure of what I was doing until it slipped and the insulation
was cut


https://www.dropbox.com/s/0zwcfigdo7...burnt.JPG?dl=0

On Fri, 16 Oct 2015 17:09:39 -0500, philo wrote:

On 10/16/2015 04:29 PM, Texas Kingsnake wrote:
Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and
off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about to fail
and is drawing a huge amount of current at startup? How do you even measure
the inrush(?) current in such a case. Would pressing on the wire near the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

TKS





Yes, the power has to be OFF


...however... DO NOT FOOL with it . call a licensed electrician ASAP


Just tightening the connection is not going to be a fix as since there
was arcing, some burned wires and connectors will need to be replaced

BTW it is free for the power company to come out and pull the meter.
No reason not to. No reason to call an electrician either.

When I tightened my mains, the power company guy was leaning on the
wall watching me and even loaned me his 1/2 inch Allen wrench for the
neutral connection.

On Fri, 16 Oct 2015 17:29:57 -0400, "Texas Kingsnake"
wrote:


I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.


It probably did loosen over time or was never tightened well, and just
shifted a small bit. What you propose makes sense. Just be safe. If the
floor is concrete, stand on a piece of plywood too. Otherwise call an
electrician. Do this soon or you could end up with a fire or at least
damaged wires or the box. A shot of PB Blaster on that screw head wont
hurt to make it move easier.

On 10/16/2015 5:53 PM, philo wrote:
On 10/16/2015 05:48 PM, dpb wrote:
On 10/16/2015 5:21 PM, philo wrote:
...

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.

Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I don't know your scope of "high power circuitry" but I'm guessing it's
far more than a house feed. I've had very good success over the years
in doing so as long as the connector/wire haven't been severely damaged.

The key is first gotta look at what the situation really is, though, not
just assume tightening alone will be enough.



I worked with circuits 80 amps and above...which would come into the
range of a house power feed.

I do believe your statement however and assume it was just a very small
arc on a relatively low current circuit.

What voltage(s)? I've worked on/used HV instrumentation where it's
definitely true that any imperfection is the death of the connectors,
and on high amperage busses (kAmp power-plant kinda' things) where it's
also true, but really never had any difficulties with the 100A 240V or
less unless it was truly awful.

The farmstead wiring here dates to as early as the first REA days in
places (1948) so I've quite a lot of experience over the house, barn,
grain elevator, hog farrowing facility plus a half-dozen or so other
outbuildings. There are loads from fractional to 15 hp scatter all over
so have a pretty wide range of power/current draws.



BTW: I found the picture of my socket wrench.

It was the day I decided that it would be OK to work on a live circuit
as long as I had my wrench all taped up.

I was 100% sure of what I was doing until it slipped and the insulation
was cut


https://www.dropbox.com/s/0zwcfigdo7...burnt.JPG?dl=0

"The road to hell..." We're all comfortable until something unexpected
goes wrong.

--

"philo" wrote in message
...
For those who may have missed my posts over the past year or so, my
background is industrial batteries and I have repaired literally thousands
of chargers whose output is anywhere from 80 to 350 amps.


When I was still new on the job , if there was a burned or tarnished
connection, I'd typically wire brush it down then sand it until everything
was smooth and shiny.


It did not take me more than a year to realize that was only a temporary
fix as the connection would always go bad again.


Once copper is heated it actually goes through a chemical change and
becomes copper oxide. If the burned portion is cleaned, the copper still
has a tarnished look to it.


If you cut a new copper wire and compare it to a cut, tarnished wire you
will see the difference.


That's why I said all must be replaced.


I agree. I worked with lots of industrial electrical equipment, lots of 480
volt 3 phase from a few amps to around 500 amps.

There were hundreds if not thousands of breakers and switch gear that was
inspected with an IR camera every year or two. If a connection shows
evidence of overheating, sometimes cleaning and tightning would solve the
problem, but often it would show back up on the next scan , usually about a
year later.

Cutting back and changing seemed to be the long term solution.

On 10/16/2015 5:38 PM, philo wrote:
On 10/16/2015 05:28 PM, trader_4 wrote:
[snip]


Once copper is heated it actually goes through a chemical change and
becomes copper oxide. If the burned portion is cleaned, the copper still
has a tarnished look to it.


If you cut a new copper wire and compare it to a cut, tarnished wire you
will see the difference.


That's why I said all must be replaced.


If some hardware was replaced that ended up actually being OK, no harm
done.

I think all see the corollary.

If it's copper, I'll check to you as the authority. If it's AL as is
the bulk of underground feeds over the past 45 years or so, is it the
same deal with arcing.

The only thing I'm going with is DON'T mess with that service drop while
it's live. Period!

If it's AL on the drop, you're definitely going to have to clean it up,
recoat with the anti-oxidant paste and really crank it down. IIRC
correctly those lugs are fitted with an Allen socket. Just way too much
that can go wrong screwing around there even if you didn't have to pull
the wire out to clean and re-coat.

He can, in the end, do whatever he wants. His widow can report back
where he went wrong.

On 10/16/2015 5:53 PM, philo wrote:
On 10/16/2015 05:48 PM, dpb wrote:
On 10/16/2015 5:21 PM, philo wrote:
...



[snip[

BTW: I found the picture of my socket wrench.

It was the day I decided that it would be OK to work on a live circuit
as long as I had my wrench all taped up.

I was 100% sure of what I was doing until it slipped and the insulation
was cut


https://www.dropbox.com/s/0zwcfigdo7...burnt.JPG?dl=0


LOL! Was it a Craftsman? What'd they say about their lifetime guarantee?

On Fri, 16 Oct 2015 17:29:57 -0400, "Texas Kingsnake"
wrote:

Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and
off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about to fail
and is drawing a huge amount of current at startup? How do you even measure
the inrush(?) current in such a case. Would pressing on the wire near the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

TKS

Your main power lug is loose - and quite possibly burned. You may or
may not be able to tighten it. Trying to tighten it with the circuit
live COULD get nasty if the lug is damaged and comes off the buss when
you try to tighten it.

I have had a burned lug on a service panel and was lucky enough to be
able to find a used replacement lug - and even luckier to be able to
replace it and the cable connecting to it which had also been damaged
by the arcing.

And yes, just pushing on it would possibly temporarily correct it.

On Fri, 16 Oct 2015 17:21:46 -0500, philo wrote:

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.


Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I guess 12VDC would qualify as low power, but some still draws a lot of
amps. I've had to clean corroded wires many times on vehicles, and
reconnect them. Just recently, there was a melted plug under my dash,
powering the blower motor (for heater). I removed the plug and found the
wires overheated, so I cut off a half inch on each end. That was all I
could spare. Then I soldered them and taped. That plug is a common
problem on my vehicle, and there have been some fires because of it. The
plug was under rated for the current draw.There was a recall for it, but
that expired years ago. The vehicle is a 1995 model. According to what a
mechanic told me, the recall had them remove the plug and crimp the
wires together. I think soldering is a far better splice than crimp
connectors.

On Fri, 16 Oct 2015 18:04:12 -0500, wrote:

On Fri, 16 Oct 2015 17:29:57 -0400, "Texas Kingsnake"
wrote:


I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.


It probably did loosen over time or was never tightened well, and just
shifted a small bit. What you propose makes sense. Just be safe. If the
floor is concrete, stand on a piece of plywood too. Otherwise call an
electrician. Do this soon or you could end up with a fire or at least
damaged wires or the box. A shot of PB Blaster on that screw head wont
hurt to make it move easier.
And if it arcs again it will GUARANTEE you get a fire!!!!

On 10/16/2015 8:24 PM, wrote:


Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?


Your main power lug is loose - and quite possibly burned. You may or
may not be able to tighten it. Trying to tighten it with the circuit
live COULD get nasty if the lug is damaged and comes off the buss when
you try to tighten it.

I have had a burned lug on a service panel and was lucky enough to be
able to find a used replacement lug - and even luckier to be able to
replace it and the cable connecting to it which had also been damaged
by the arcing.

And yes, just pushing on it would possibly temporarily correct it.


I agree that it is best to inspect and replace burnt parts as needed.
OTOH, if he can stop the arcing temporarily it is safer than allowing it
to continue until he can do it right. If he wants to be completely
safe, pull the meter until you can get an electrician.

On Fri, 16 Oct 2015 17:29:57 -0400, "Texas Kingsnake"
wrote:

Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and
off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.


By the way, you may also have a bad breaker causing that hum. Fix the
Mains connection first, then watch and listen to the breaker feeding the
laundry. If it does hum, replace it!

I will mention that when a motor starts, it draws a lot more amperage
than when it's running. That's why you see that spark when it starts.

If you do shut off the power to repair that mains lug, check the other
ones too (neutral included). And apply some Anti-Sieze to the screws so
they are easier to move in the future. (Thats if they turn at all. That
arcing could have welded that problem one in place, which means you have
a bigger problem.

On Fri, 16 Oct 2015 19:30:15 -0500, wrote:

On Fri, 16 Oct 2015 17:21:46 -0500, philo wrote:

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.


Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I guess 12VDC would qualify as low power, but some still draws a lot of
amps. I've had to clean corroded wires many times on vehicles, and
reconnect them. Just recently, there was a melted plug under my dash,
powering the blower motor (for heater). I removed the plug and found the
wires overheated, so I cut off a half inch on each end. That was all I
could spare. Then I soldered them and taped. That plug is a common
problem on my vehicle, and there have been some fires because of it. The
plug was under rated for the current draw.There was a recall for it, but
that expired years ago. The vehicle is a 1995 model. According to what a
mechanic told me, the recall had them remove the plug and crimp the
wires together. I think soldering is a far better splice than crimp
connectors.
A Ford by chance? My 1995 Mercury Mystique had the same issues

On Fri, 16 Oct 2015 21:43:45 -0400, Ed Pawlowski wrote:

On 10/16/2015 8:24 PM, wrote:


Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?


Your main power lug is loose - and quite possibly burned. You may or
may not be able to tighten it. Trying to tighten it with the circuit
live COULD get nasty if the lug is damaged and comes off the buss when
you try to tighten it.

I have had a burned lug on a service panel and was lucky enough to be
able to find a used replacement lug - and even luckier to be able to
replace it and the cable connecting to it which had also been damaged
by the arcing.

And yes, just pushing on it would possibly temporarily correct it.


I agree that it is best to inspect and replace burnt parts as needed.
OTOH, if he can stop the arcing temporarily it is safer than allowing it
to continue until he can do it right. If he wants to be completely
safe, pull the meter until you can get an electrician.
Absolutely no way you need to (or even should) pull the meter. Just
turn off the main breaker and no current can flow. No current means no
arc. No heat. No problem.

On 10/16/2015 06:34 PM, dpb wrote:
On 10/16/2015 5:53 PM, philo wrote:
On 10/16/2015 05:48 PM, dpb wrote:
On 10/16/2015 5:21 PM, philo wrote:
...

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.

Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is
long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I don't know your scope of "high power circuitry" but I'm guessing it's
far more than a house feed. I've had very good success over the years
in doing so as long as the connector/wire haven't been severely damaged.

The key is first gotta look at what the situation really is, though, not
just assume tightening alone will be enough.



I worked with circuits 80 amps and above...which would come into the
range of a house power feed.

I do believe your statement however and assume it was just a very small
arc on a relatively low current circuit.

What voltage(s)? I've worked on/used HV instrumentation where it's
definitely true that any imperfection is the death of the connectors,
and on high amperage busses (kAmp power-plant kinda' things) where it's
also true, but really never had any difficulties with the 100A 240V or
less unless it was truly awful.



Since I worked on batteries and chargers the voltage was usually under
72 volts... but it was DC which is a whole different thing from AC.

My main point however was that if the OP heard hissing there was
undoubtedly arcing and he really needs to call an electrician.



(the rest read but snipped for brevity)

On 10/16/2015 06:44 PM, Unquestionably Confused wrote:
On 10/16/2015 5:53 PM, philo wrote:
On 10/16/2015 05:48 PM, dpb wrote:
On 10/16/2015 5:21 PM, philo wrote:
...



[snip[

BTW: I found the picture of my socket wrench.

It was the day I decided that it would be OK to work on a live circuit
as long as I had my wrench all taped up.

I was 100% sure of what I was doing until it slipped and the insulation
was cut


https://www.dropbox.com/s/0zwcfigdo7...burnt.JPG?dl=0


LOL! Was it a Craftsman? What'd they say about their lifetime guarantee?






I knew better than to try and collect warranty on that one...
yes it was Craftsman
and I used the socket set the entire 38 years I was on the job.

The socket set was the only thing that lasted the whole time...and when
it was time for me to turn in my tools, I kept it as a retirement present.

Obviously I replaced the parts shown in the photo and I took warranty on
the ratchet a few times...but all other sockets went the distance.

On 10/16/2015 07:30 PM, wrote:
On Fri, 16 Oct 2015 17:21:46 -0500, philo wrote:

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.


Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I guess 12VDC would qualify as low power, but some still draws a lot of
amps. I've had to clean corroded wires many times on vehicles, and
reconnect them. Just recently, there was a melted plug under my dash,
powering the blower motor (for heater). I removed the plug and found the
wires overheated, so I cut off a half inch on each end. That was all I
could spare. Then I soldered them and taped. That plug is a common
problem on my vehicle, and there have been some fires because of it. The
plug was under rated for the current draw.There was a recall for it, but
that expired years ago. The vehicle is a 1995 model. According to what a
mechanic told me, the recall had them remove the plug and crimp the
wires together. I think soldering is a far better splice than crimp
connectors.




I worked a lot with connectors up to 350 amps and UL approved either
soldering or crimping.


No one at my company had a problem with either method as long as done
properly.


The important thing you did right was to cut back to good copper.


We usually crimped just because it was faster and no flames were needed
to do so.

On 10/16/2015 09:21 PM, wrote:
On Fri, 16 Oct 2015 19:30:15 -0500, wrote:

On Fri, 16 Oct 2015 17:21:46 -0500, philo wrote:

I worked on high power circuitry for 38 years and cleaning a bad
connection is not the answer.


Believe me I've tried. Once a connection has been burned and tarnished
no amount of cleaning can ever again provide a satisfactory connection.
All connectors and wires must be replaced...or if the wire/cable is long
enough...cut back to good , fresh copper.


For low power circuitry, cleaning is probably OK though.

I guess 12VDC would qualify as low power, but some still draws a lot of
amps. I've had to clean corroded wires many times on vehicles, and
reconnect them. Just recently, there was a melted plug under my dash,
powering the blower motor (for heater). I removed the plug and found the
wires overheated, so I cut off a half inch on each end. That was all I
could spare. Then I soldered them and taped. That plug is a common
problem on my vehicle, and there have been some fires because of it. The
plug was under rated for the current draw.There was a recall for it, but
that expired years ago. The vehicle is a 1995 model. According to what a
mechanic told me, the recall had them remove the plug and crimp the
wires together. I think soldering is a far better splice than crimp
connectors.
A Ford by chance? My 1995 Mercury Mystique had the same issues




Oh such memories. My first paid electrical repair job was my dad's '55
Chevy. Found a bad connector at the brake light. Cut the connector
off...soldered and taped and got a buck from my dad. Think that was
around 1962.

On 10/16/2015 06:37 PM, Ralph Mowery wrote:
"philo" wrote in message
...
For those who may have missed my posts over the past year or so, my
background is industrial batteries and I have repaired literally thousands
of chargers whose output is anywhere from 80 to 350 amps.


When I was still new on the job , if there was a burned or tarnished
connection, I'd typically wire brush it down then sand it until everything
was smooth and shiny.


It did not take me more than a year to realize that was only a temporary
fix as the connection would always go bad again.


Once copper is heated it actually goes through a chemical change and
becomes copper oxide. If the burned portion is cleaned, the copper still
has a tarnished look to it.


If you cut a new copper wire and compare it to a cut, tarnished wire you
will see the difference.


That's why I said all must be replaced.


I agree. I worked with lots of industrial electrical equipment, lots of 480
volt 3 phase from a few amps to around 500 amps.

There were hundreds if not thousands of breakers and switch gear that was
inspected with an IR camera every year or two. If a connection shows
evidence of overheating, sometimes cleaning and tightning would solve the
problem, but often it would show back up on the next scan , usually about a
year later.

Cutting back and changing seemed to be the long term solution.







You had a damn good job there. In the few years before I retired I saw a
lot of companies getting the "IR checkup". Fix problems before they
start...good idea.

On 10/16/2015 06:42 PM, Unquestionably Confused wrote:
On 10/16/2015 5:38 PM, philo wrote:
On 10/16/2015 05:28 PM, trader_4 wrote:
[snip]


Once copper is heated it actually goes through a chemical change and
becomes copper oxide. If the burned portion is cleaned, the copper still
has a tarnished look to it.


If you cut a new copper wire and compare it to a cut, tarnished wire you
will see the difference.


That's why I said all must be replaced.


If some hardware was replaced that ended up actually being OK, no harm
done.

I think all see the corollary.

If it's copper, I'll check to you as the authority. If it's AL as is
the bulk of underground feeds over the past 45 years or so, is it the
same deal with arcing.

The only thing I'm going with is DON'T mess with that service drop while
it's live. Period!

If it's AL on the drop, you're definitely going to have to clean it up,
recoat with the anti-oxidant paste and really crank it down. IIRC
correctly those lugs are fitted with an Allen socket. Just way too much
that can go wrong screwing around there even if you didn't have to pull
the wire out to clean and re-coat.

He can, in the end, do whatever he wants. His widow can report back
where he went wrong.








Worked on a lot high-powered transformers and if copper I could usually
fix them by cutting back to clean copper and putting on a new lug.

Eventually I gave up on aluminum because no matter what I did, the
connection would burn out again. I might have had better luck though if
I used anti-oxidant paste. Too late now, I'm retired.

On 10/16/2015 08:43 PM, Ed Pawlowski wrote:
On 10/16/2015 8:24 PM, wrote:


Does the power *really* need to be killed at the meterhead? I've
changed
out breakers without killing main power (so much frikkin' stuff needs
to be
reset after a power shutdown that I hate doing it)?


Your main power lug is loose - and quite possibly burned. You may or
may not be able to tighten it. Trying to tighten it with the circuit
live COULD get nasty if the lug is damaged and comes off the buss when
you try to tighten it.

I have had a burned lug on a service panel and was lucky enough to be
able to find a used replacement lug - and even luckier to be able to
replace it and the cable connecting to it which had also been damaged
by the arcing.

And yes, just pushing on it would possibly temporarily correct it.


I agree that it is best to inspect and replace burnt parts as needed.
OTOH, if he can stop the arcing temporarily it is safer than allowing it
to continue until he can do it right. If he wants to be completely
safe, pull the meter until you can get an electrician.



Or determine which branh it's on and simply not use that side.

On Fri, 16 Oct 2015 17:29:57 -0400, "Texas Kingsnake"
wrote:

Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and

Hint: This is the main. The meter is the only way to turn off power
here.

off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about to fail
and is drawing a huge amount of current at startup? How do you even measure
the inrush(?) current in such a case. Would pressing on the wire near the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

TKS

On Fri, 16 Oct 2015 22:56:43 -0400, Seymore4Head
wrote:

On Fri, 16 Oct 2015 17:29:57 -0400, "Texas Kingsnake"
wrote:

Hi there. Back again with a new problem.

My wife was doing the laundry and I was working near the circuit breaker
panel. When she turned the machine on I heard a loud buzz from inside the
box. Less than a second long. I had her turn the machine off, took off
the panel cover and watched as she turned the machine back on. I saw arcing
at the left-handed side of the panel at the point where the heavy black
cable from the street enters the box. I had her turn the machine on and

Hint: This is the main. The meter is the only way to turn off power
here.

I forgot to add you do not have to turn the power off, but there is no
reason not to.


off and it happened again. Then I pushed the black wire right where it
enters the clamp and it hasn't happened again, despite having all the same
lights and appliances on.

I am thinking the clamp has loosened over time. I am going to get a
well-insulated screwdriver, put on very heavy rubber gloves and am going to
try to tighten the clamp which may have not been tightened in 40 years.

Does the power *really* need to be killed at the meterhead? I've changed
out breakers without killing main power (so much frikkin' stuff needs to be
reset after a power shutdown that I hate doing it)?

Anything else I should consider? Is the washine machine motor about to fail
and is drawing a huge amount of current at startup? How do you even measure
the inrush(?) current in such a case. Would pressing on the wire near the
clamp cure it temporarily or is some other process in play?

What would account for it happening twice and then not happening again. The
only real intervening act was to push on the wire jacket at the point it
enters the clamp on the circuit panel. Very strange.

TKS

wrote in message
...
I guess 12VDC would qualify as low power, but some still draws a lot of
amps. I've had to clean corroded wires many times on vehicles, and
reconnect them. Just recently, there was a melted plug under my dash,
powering the blower motor (for heater). I removed the plug and found the
wires overheated, so I cut off a half inch on each end. That was all I
could spare. Then I soldered them and taped. That plug is a common
problem on my vehicle, and there have been some fires because of it. The
plug was under rated for the current draw.There was a recall for it, but
that expired years ago. The vehicle is a 1995 model. According to what a
mechanic told me, the recall had them remove the plug and crimp the
wires together. I think soldering is a far better splice than crimp
connectors.


If the connection is subject ot viberartion, the crimp , if done correctly,
is beter than soldering. The solder makes it into a solid wire and flexing
will break it over time.

On Fri, 16 Oct 2015 23:08:39 -0400, "Ralph Mowery"
wrote:


wrote in message
.. .
I guess 12VDC would qualify as low power, but some still draws a lot of
amps. I've had to clean corroded wires many times on vehicles, and
reconnect them. Just recently, there was a melted plug under my dash,
powering the blower motor (for heater). I removed the plug and found the
wires overheated, so I cut off a half inch on each end. That was all I
could spare. Then I soldered them and taped. That plug is a common
problem on my vehicle, and there have been some fires because of it. The
plug was under rated for the current draw.There was a recall for it, but
that expired years ago. The vehicle is a 1995 model. According to what a
mechanic told me, the recall had them remove the plug and crimp the
wires together. I think soldering is a far better splice than crimp
connectors.


If the connection is subject ot viberartion, the crimp , if done correctly,
is beter than soldering. The solder makes it into a solid wire and flexing
will break it over time.

A properly soldered connection is still better than an improperly
crimped connection. Soldered connections should be re-enforced with
heat shrink tupe beyond the solder-stiffened area of the wire.

wrote in message
...
A properly soldered connection is still better than an improperly
crimped connection. Soldered connections should be re-enforced with
heat shrink tupe beyond the solder-stiffened area of the wire.

But the proper crimped connection is a lot berter than an improperly
soldered connectiion.

You are defeating the purpose when not doing things the correct way.

Howdy folks,

I read all the excellent replies (thanks to all). Here's what I am going to
do. I will put on my long linesman rubber gloves, place a thick rubber mat
on the floor in front of the box and use a large insulated screwdriver to
see if the screw (it's slotted, not hex-keyed) will turn and by how much.

I haven't been able to recreate the arcing since pushing the feed wire
slightly right above the bus clamp. I will, on next trip to the box, look
for discoloration of the wire in the clamp area and burn or sputter marks
near the terminal. I will also try to measure the washing machine's start
up current to see if it's abnormally high (if my clamp meter can register
it - I believe it has a peak lock but am not sure - just got a new HF one to
replace the Wavetek that had a terminal battery leak.)

I appreciate the concern for my life, Philo, and my wife is making sure my
will is in order. I will wear goggles since I know a spasm of some sort
could arc weld my screwdriver to the panel and throw molten metal into my
eyes.

DPB - I'll try to take a close up picture of the wire where it enters the
clamp but no guarantees. The last time I uploaded pictures no one could see
them. I'll at least try to describe what I see now I know what I am looking
for.

I'm upstairs now, but for some reason I thought the feed wire was tinned
copper but it could easily be I was looking at aluminum wire and didn't
realize it. The upgrade to the panel occurred in 1972 according to the
labels, and IIRC that's when aluminum was still thought to be a good idea in
residential wiring. I think you're right in that just pushing on the wire
changed something because I cannot get the arc to occur DESPITE putting two
space heaters running at 15A on the outlets served by the left side of the
panel.

It's really just random chance we were both standing where we were when this
happened - who knows how long it could have continued. I tried to assure my
wife the reason that the circuits are in the metal box was to prevent an
arcing connection from throwing sparks into the room. She's with Philo and
thinks resetting the clocks and VCRs is worth the safety edge of working on
a de-energized circuit. My opinon is "meh, you got to go sometime and
getting eletrocuted is probably better than some ways of dying!!!"

I have a neighbor who is an electrician so I am going to consult with him
tomorrow about what to do. If it's discolored and corroded at the entry to
the clamp, I will consider replacing the entire feed wire from the meter to
the panel since I think that's a relative small piece of what looks to be #6
wire - can't read the markings but am on my way downstairs with a camera
with a macro lens. If all the feed wires are AL, I will consider replacing
all three wires from the panel to the meter with new copper. If it happened
on one wire, it's possible it could happen on the others.

And , if the screw won't turn, I won't be spraying it with
anything flammable while it's live. I feel comfortable trying to tighten
the screw and take photos while it's live, but if it requires closer
inspection, of course I will kill the power to the panel.

Thanks again for all the thoughtful replies. It might be a few days before
you hear back from me if the worst comes to pass - well, if the very worst
comes to pass (I die) you won't hear from me so I will try my best to let
you know if I survive.

The worst shocks I've ever gotten were not from replacing breakers in a live
panel but where I least expected it. I was changing a light bulb in a
flooded basement when it popped in my hand and I was suddenly touching the
naked filament wire. Or when I was working on a space heater that had
stopped heating and thought I had unplugged it from the outlet but I had
actually unplugged my DC variable power supply that was plugged in next to
it. ZAPPPPPPP!

TKS

On Sat, 17 Oct 2015 00:08:21 -0400, "Ralph Mowery"
wrote:


wrote in message
.. .
A properly soldered connection is still better than an improperly
crimped connection. Soldered connections should be re-enforced with
heat shrink tupe beyond the solder-stiffened area of the wire.

But the proper crimped connection is a lot berter than an improperly
soldered connectiion.

You are defeating the purpose when not doing things the correct way.

But the "properly crimped connection" is not made with a $3.00
crimping tool and an insulated butt crimp connector consisting of a
tinned copper tube and a hard plastic sleeve on it. A properly crimped
connector requires a crimper with the correct size die for the
connector, and a "calibrated" pressure, to ensure a "gas tite"
connection - and an insulating sleeve that seals to the insulation,
keeping moisture and other corrosive contamination away from the
joint.

It is easier for a reasonably competent craftsman to make a decent
soldered joint with tools at hand than to do a "proper" crimp without
the specialized tools required.

That said, a "proper" crimped connection IS the preferred method of
joining flexible conductors.

On 10/16/2015 11:59 PM, Texas Kingsnake wrote:
Howdy folks,

[snip]


DPB - I'll try to take a close up picture of the wire where it enters the
clamp but no guarantees. The last time I uploaded pictures no one could see
them. I'll at least try to describe what I see now I know what I am looking
for.


Problem with that is that this is not a binary group. You have to
upload the photo to a cloud source (Dropbox.com is free and easy to use)
and then post a link (again easy with Dropbox) in your posting here. We
just click on the link and ...