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Bad Neutrals & Wire Nut question

W

Wayne G. Dengel

Jan 1, 1970
0
I spend a few hours each working at a local Home Depot - Electrical Dept.

All too often, customers come by with the same problem - freshly-installed
(anywhere from 1-6 mths ago) burned out light bulbs. Bulbs are replaced -
time goes by and the newly installed ones blow out.

Other than surges (we are in Florida), what is the cause of excessive
voltage (or what else will do it??) that will "pop" light bulbs??

Another posting on a different subject suggested bad neutrals.


New subject:

While talking about bad neutrals, does the Code say that wires MUST be
twisted first before wire nuts are applied?* Packages of wire nuts sold at
HD say that twisting is recommended but not required.

*In my own home, about 8-9 years after original installation, #6 and a #12
had been wired together in a 'J' box serving an oven. Oven quite working.
Breaker OK. Found wires in J box standing side-by-side, literally, not
twisted. Wire nut had melted away. Here is a case where they should have
been twisted. However, I notice that here in FL, electricians simply twist
on the nut thus expecting a good bond.

Wayne
 
I spend a few hours each working at a local Home Depot - Electrical Dept.

All too often, customers come by with the same problem - freshly-installed
(anywhere from 1-6 mths ago) burned out light bulbs. Bulbs are replaced -
time goes by and the newly installed ones blow out.

Other than surges (we are in Florida), what is the cause of excessive
voltage (or what else will do it??) that will "pop" light bulbs??

In the Ft Myers area you will see the voltage cruising around 124-125
volts most of the time. That is tough on light bulbs.


:
While talking about bad neutrals, does the Code say that wires MUST be
twisted first before wire nuts are applied?* Packages of wire nuts sold at
HD say that twisting is recommended but not required.

*In my own home, about 8-9 years after original installation, #6 and a #12
had been wired together in a 'J' box serving an oven. Oven quite working.
Breaker OK. Found wires in J box standing side-by-side, literally, not
twisted. Wire nut had melted away. Here is a case where they should have
been twisted. However, I notice that here in FL, electricians simply twist
on the nut thus expecting a good bond.


Ideal and other manufacturers do not require twisting. If the wires
are properly inserted they will be totally encapsulated in the wirenut
spring. If the twist is not very concentric and tight you might
actually make the connection worse.
 
S

SQLit

Jan 1, 1970
0
Wayne G. Dengel said:
I spend a few hours each working at a local Home Depot - Electrical Dept.

All too often, customers come by with the same problem - freshly-installed
(anywhere from 1-6 mths ago) burned out light bulbs. Bulbs are replaced -
time goes by and the newly installed ones blow out.

Other than surges (we are in Florida), what is the cause of excessive
voltage (or what else will do it??) that will "pop" light bulbs??

Another posting on a different subject suggested bad neutrals.


New subject:

While talking about bad neutrals, does the Code say that wires MUST be
twisted first before wire nuts are applied?* Packages of wire nuts sold at
HD say that twisting is recommended but not required.

*In my own home, about 8-9 years after original installation, #6 and a #12
had been wired together in a 'J' box serving an oven. Oven quite working.
Breaker OK. Found wires in J box standing side-by-side, literally, not
twisted. Wire nut had melted away. Here is a case where they should have
been twisted. However, I notice that here in FL, electricians simply twist
on the nut thus expecting a good bond.

Wayne

there are a lot of electrical workers, and few electricians. Difference is
craftsmanship.
I have never twisted wires before inserting into a wire nut. When I am done
the wires are twisted together. That is just the way I was taught 30 + years
ago.

Your description of a #6 and a #12 tied together on the surface sounds
seriously wrong. If the over current device is set for the #6 wire or more
than 20 amps then the #12 wire is seriously under protected..... Fire
insurance paid up?
This description sound about right when inexperienced folks are doing work
that they have no business doing. Please have someone trace down the 6 and
12 and verify the load locations and overcurrent devices before trouble
arrives at your front door.
 
W

w_tom

Jan 1, 1970
0
The wires must be twisted to make firm contact with each
other. Then the wire nut is twisted on to make more
electrical contacts between wires. You need not twist wires
together before putting the wire nut on. The wire nut can
twist those wires together. But when you are done, and if you
remove the wire nut, then those wires must be twisted together
sufficiently to remain connected - without wire nut.

These pictures and descriptions may provide useful
additional information:
http://www.inspect-ny.com/aluminum/piclib02.htm

If the wiring is aluminum and not properly twisted together,
then this is a serious and potential fire hazard. Copper wire
tends to be more forgiving. But still not forgiving enough
that wire is not twisted together.
 
W

w_tom

Jan 1, 1970
0
Some numbers. An incandescent light bulb running at about
127 volts will burn out twice as fast as that bulb at 120
volts. Will burn out about three times as fast at 130 volts.

Some light bulbs suspended from those new composite joists
tend to suffer more from vibration. If the basement light is
on and kids are running upstairs, then the hot filament will
tend to fail more frequently.

Bad neutrals would create premature bulb failure IF the
neutral wire failure causes a voltage increase - such as when
a 120 volt heavy appliance on the other side of 240 volts
attempts to push more current through a poorly connected
neutral wire.
 
B

Bud--

Jan 1, 1970
0
w_tom said:
The wires must be twisted to make firm contact with each
other. Then the wire nut is twisted on to make more
electrical contacts between wires. You need not twist wires
together before putting the wire nut on. The wire nut can
twist those wires together. But when you are done, and if you
remove the wire nut, then those wires must be twisted together
sufficiently to remain connected - without wire nut.

I seldom twist wires and the wirenut doesn't necessarily twist them.

I do use wirenuts with 'live springs'. The springs deform over the wires
and make more contact and, I think, keep the connection tighter. When
the wirenut is removed you can see the spring has been deformed. At
least some of the wirenuts made by Buchanan and 3M have live springs. At
least some of the wirenuts made by Ideal don't.

Bud--
 
W

Wayne G. Dengel

Jan 1, 1970
0
Sorry if I misled. #6, properly protected from main service to the J box.
The oven's feed was a #12. Here is where the 6 and 12 were "nutted"
together.

Wayne
 
R

Rick

Jan 1, 1970
0
SQLit said:
there are a lot of electrical workers, and few electricians. Difference is
craftsmanship.
I have never twisted wires before inserting into a wire nut. When I am
done
the wires are twisted together. That is just the way I was taught 30 +
years
ago.

Your description of a #6 and a #12 tied together on the surface sounds
seriously wrong. If the over current device is set for the #6 wire or more
than 20 amps then the #12 wire is seriously under protected..... Fire
insurance paid up?
This description sound about right when inexperienced folks are doing work
that they have no business doing. Please have someone trace down the 6
and
12 and verify the load locations and overcurrent devices before trouble
arrives at your front door.

hi sqlit.. He said the #6 was for his oven.. can't you use #12 as a drop?
depending to what.. Even though #6 is good for 60 amp.. isn't that
alot for an oven? don't you guys have inspectors that pass by every house
before the are built?
 
F

Fred

Jan 1, 1970
0
Hey Tom!

Interesting numbers re lamp failures at different voltages.

Main problems with blowing lamps that I have found isn't caused by loose
wire nuts....its caused by loose neutrals on the neutral bar in the service
panel.

Fred
 
A

Anthony

Jan 1, 1970
0
New subject:

While talking about bad neutrals, does the Code say that wires MUST be
twisted first before wire nuts are applied?* Packages of wire nuts
sold at HD say that twisting is recommended but not required.

Wire nut installed on straight wires, then twisted until the wires make 3
wraps behind the nut. YMMV



--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email
 
J

John Ray

Jan 1, 1970
0
I'm guessing the oven was changed from electric to gas, In which case it
should be on a 20amp breaker max, with one of the phase conductors converted
to a neutral. Tapping anything as large as a #6 should really be done with a
split bolt and rubber tape. I never did like those big blues.

John
 
K

keith

Jan 1, 1970
0
Some numbers. An incandescent light bulb running at about
127 volts will burn out twice as fast as that bulb at 120
volts. Will burn out about three times as fast at 130 volts.

Lamp failure goes something like the 12th power of voltage. Given that,
127V ( (127/120)^12) is about 2x, and 130V is about 2.6x. If high voltage
is suspected, buy 130V bulbs. They are available.
Some light bulbs suspended from those new composite joists
tend to suffer more from vibration. If the basement light is on and
kids are running upstairs, then the hot filament will tend to fail more
frequently.

Funny thing; I just had new "hardwwod" (bamboo, actually) installed on
the first floor. I went down into the basement and one of the lights
went. No, the fillament was fine, but the constant banging from the
pneumatic flooring stapler backed it out of the socket! ;-/
Bad neutrals would create premature bulb failure IF the
neutral wire failure causes a voltage increase - such as when a 120 volt
heavy appliance on the other side of 240 volts attempts to push more
current through a poorly connected neutral wire.

....or an intermittent (which should be obvious).
 
K

keith

Jan 1, 1970
0
Wire nut installed on straight wires, then twisted until the wires make 3
wraps behind the nut. YMMV

That's what I do (twist the crap outta them). I always wonder about wire
nuts and stranded wire though.
 
A

Anthony

Jan 1, 1970
0
That's what I do (twist the crap outta them). I always wonder about
wire nuts and stranded wire though.

Always use ferrules on stranded wire at any terminal, especially if you
are wire nutting them.

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email
 
J

John Gilmer

Jan 1, 1970
0
Ideal and other manufacturers do not require twisting. If the wires
are properly inserted they will be totally encapsulated in the wirenut
spring. If the twist is not very concentric and tight you might
actually make the connection worse.

In my "in home" experience with the house with loads of DIY wiring by the
former owner, twisting the wires before putting on the wire nut is
definitely counter productive.

One joint in a J-box holding up a ceiling fan opened up. It took me some
time to figure that out (who would figure that a bunch of wires twisted
together under a wirenut would OPEN.)

That was 7 years ago. I have done all kinds of wiring in the place since
(including re-wiring a bunch of J-boxes) and I just poke the wires into the
wirenut and THEN start twisting. No failures (none expected) and one the
occasion I have to undo a connection it's somewhat less messy than the
"doubly twisted" connections.

Of course, the wirenut does end up twisting the wires together.
 
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