Sorry if you see this twice. I didn't see it make it out the first time.
Last week I had the Electrical Inspector at my house to check on the central
air conditioning which I had installed at the end of last summer. While he
was there, I took the opportunity to review with him my plans for adding a
sub panel for my shop to my existing service.
My plan is to use the old load center left over from my house prior to
renovations. This already has a 100 amp main breaker and all I have to do
is separate the neutral and the ground in this box. I also explained to him
that I would be adding a 100 amp double breaker to my main box. My main box
has 40 breaker slots (about 3/4s occupied) and I indicated that I would put
the new breakers near the bottom, just below the 50 amp double breakers for
the central air.
The inspector said to me that I might consider moving the higher amp
breakers to the top of the box. That would minimize the lights dimming when
these loads came on. My lights do dim a little when the A/C first starts
up.
My questions then to the learned members of this group:
1. Do you agree that moving of the hi-load breakers to the top of
the box will really minimize the lights dimming when their loads come on?
2. If true then I will move some existing breakers. To do so, I will
have to extend the black wire on some 15 and 20 amp breakers. Are crimp-on
splices acceptable for this?
Thanks,
Bill Leonhardt
no! the dimming is due to decrease voltage as the higher amps are drawn
(voltage drop). that decreased voltage will be the same over the entire
bus length. that's why they will dim in the house also which is on
another buss altogether and efectivly "higher up" the buss.
this is not worth the hassle of moving breakers and splicing wires.
BRuce
Bill Leonhardt wrote:
> Sorry if you see this twice. I didn't see it make it out the first time.
>
>
>
> Last week I had the Electrical Inspector at my house to check on the central
> air conditioning which I had installed at the end of last summer. While he
> was there, I took the opportunity to review with him my plans for adding a
> sub panel for my shop to my existing service.
>
> My plan is to use the old load center left over from my house prior to
> renovations. This already has a 100 amp main breaker and all I have to do
> is separate the neutral and the ground in this box. I also explained to him
> that I would be adding a 100 amp double breaker to my main box. My main box
> has 40 breaker slots (about 3/4s occupied) and I indicated that I would put
> the new breakers near the bottom, just below the 50 amp double breakers for
> the central air.
>
> The inspector said to me that I might consider moving the higher amp
> breakers to the top of the box. That would minimize the lights dimming when
> these loads came on. My lights do dim a little when the A/C first starts
> up.
>
> My questions then to the learned members of this group:
>
> 1. Do you agree that moving of the hi-load breakers to the top of
> the box will really minimize the lights dimming when their loads come on?
>
> 2. If true then I will move some existing breakers. To do so, I will
> have to extend the black wire on some 15 and 20 amp breakers. Are crimp-on
> splices acceptable for this?
>
>
>
>
> Thanks,
>
> Bill Leonhardt
>
>
--
---
BRuce
In article <[email protected]>,
Bob S. <[email protected]> wrote:
>Wait a minute guy's. Why the big no-no on crimping the wires to extend
>them?
>
>I ask this since it was last year when I purchased an emergency generator
>and asked here about how they wire up the CB panels for the generators and
>... asked the local utility for advice.
>
>Both came back with using wire nuts inside the panel was ok and per code.
>This is the same thing electrically and using wire nuts - not crimp-ons and
>special crimpers.
>
>So did the world change while I wasn't looking?
I dunno. :) "Code" requirements _do_ vary.
At least as of the 1997 NEC, any sort of splice in wiring _inside_ the
breaker panel was verboten. OK in a junction box external to the panel.
Cannot run secondary wiring _through_ the panel, either.
Can't even run two wires to a single breaker.
thank you for the last 2 posts, I watch a lot of these electrical posts
and am amazed the "information" that is passed off in here. As an "old
time" electrician (not knob and tube though) I assumed the code could
have changed but did not see any logic in prohibiting splices in the
panel. After all it is just another big metal box.
BRuce
Greg wrote:
>>Can't even run two wires to a single breaker.
>
>
> Depends on the listing of the breaker. <example>Square D QO breakers are listed
> for 1 or 2 conductors. If there are 2 slots, one on each side of the screw it
> is usually listed for 2 wires. That should be on that tiny label on the
> breaker.
--
---
BRuce
>At least as of the 1997 NEC, any sort of splice in wiring _inside_ the
>breaker panel was verboten. OK in a junction box external to the panel.
>
HUH?
Cite that, as soon as you can find a 97 NEC (they were 96 or 99)
What the code really says (312.8) is you can't use circuit breaker enclosures
as "junction boxes, raceways or auxilary gutters" and that splices made in
these enclosures can't fill the wiring space at any cross section to more than
40%. The total conductors, taps and splices can't occupy the total wiring space
more than 75%.
In layman's terms that means I can't bring branch circuit conductors back into
the box for a splice and go back out to the load but if the splice is in the
conductor that terminates in the panelboard it is OK. With that said most
inspectors won't let you go crazy in there since those 40% and 75% are going to
be more of a judgement call than a physical measurement.
BRuce <BRuce> wrote:
> thank you for the last 2 posts, I watch a lot of these electrical posts
> and am amazed the "information" that is passed off in here. As an "old
> time" electrician (not knob and tube though) I assumed the code could
> have changed but did not see any logic in prohibiting splices in the
> panel. After all it is just another big metal box.
While not strictly forbidden, a lot of inspectors don't like
to see it. I can see their point in new construction. Splices
in the breaker box smacks of sloppy workmanship if it's new
stuff. Accomodating changes is another story though.
Bill Ranck
Blacksburg, Va.
>
>1. Do you agree that moving of the hi-load breakers to the top of
>the box will really minimize the lights dimming when their loads come on?
Marginally so. You are talking about the resistance of the bus bars.
> If true then I will move some existing breakers. To do so, I will
>have to extend the black wire on some 15 and 20 amp breakers. Are crimp-on
>splices acceptable for this?
>
Not unless you have the right crimping tools and the right splices. This is not
the ones you get at Home Depot.
I would avoid unnecessary splicing for a marginal fix to a problem.
You may also be seeing a lot of resistance in the drop and other connectios
that makes the busbar resistance inconsequential. Do what you can do along
these lines where it is easy but I wouldn't introduce one can of worms
(unnecessary splices) to try to fix another one.
It's highly unlikely that moving the high curent breaker will make any
difference in the dimming of lights. This is typically caused by a high
impedance power line. If you have any significant resistance in the buss bar,
in the set up you have now, it would be getting pretty hot with all that
current running through it.
>
>
>
>
Remove the 'remove' in my address to e:mail me.
LRod said:
>I'm always amused by this topic, especially when perpetuated by people
>who should know better.
As my follow up to this stated:
"Some of the cheap contractor-pack load panels are marginal affairs,
and the bus bars are barely adequate for the loads they are rated at.
A high quality service panel *should* show no improvement from this.
But in theory and practice, there are valid reasons for doing so."
>Look at it this way: wire resistance is measured in Ohms/100 FEET. The
>perfectly legitimate ampacity of 12 gauge wire is 20 amps. That safely
>accommodates a circuit length of dozens of feet at that current load.
>I don't know the exact cross sectional area of a typical bus in a 200
>amp/40 slot load center, but it is a WHOLE bunch more than even 10
>times that of 12ga. wire. And it's only a matter of inches long
>(probably 18 or less).
I don't recall the statement that he had a 200 amp service, but...
The problem stems from the stab connector to bus interface and the
heat which is generated under heavy loads. The bus bars in some of
these cheaper panels are nothing more than 14 G stamped steel. I have
seen these bus bars get pretty warm under load conditions. In my
opinion, it is better to contain this heat in as little an area as
possible to keep it away from the other lesser connection interfaces.
>I don't think it would be possible to measure the voltage drop on a
>typical 18" bus at 1000 amps, much less 100 or 50. You certainly
>wouldn't be able to solve light dimming by whatever insignificant
>amount it is.
Not reading the OP's question thoroughly, I probably jumped the gun on
this one. I was addressing the breaker location more than the light
dimming problem. If you are having light dimming problems, your
service or wiring is inadequate, you have a failing, high resistance
connection somewhere along the line to the panel, or the main breaker
could be failing.
>I was shocked (sorry) when I read the recommendation to put the higher
>current breakers farther up the bus in a how-to electrical book by a
>very respected author. He should have known better.
It hurts nothing, and possibly helps. When I wire a panel, I do this
for the piece of mind of knowing that everything is as theoretically
optimized as it can be.
FWIW,
Greg G.
> Last week I had the Electrical Inspector at my house to check on the
central
> air conditioning which I had installed at the end of last summer.
Its scary when people like this have inspectors jobs.
> My questions then to the learned members of this group:
>
> 1. Do you agree that moving of the hi-load breakers to the top
of
> the box will really minimize the lights dimming when their loads come on?
Horse-hockey. If your lights dim when something kicks on or off then the
light circuit itself is a little overloaded to start with or you've got some
connections that arent as good as they should be. Ex. too many lights on one
circuit, other items on the circuit with the lights that shouldnt be like
receptacles, disposals, dishwasher and such, wire size too small or breaker
too small for the said circuit. I have a simliar setup to the one you
described and my lights never dim. Even with machines going in the shop,
central air in the house, electric water heater and so on.
>
> 2. If true then I will move some existing breakers. To do so, I will
> have to extend the black wire on some 15 and 20 amp breakers. Are
crimp-on
> splices acceptable for this?
>
A big no no. If you still want to do this procedure and the wires arent long
enough then..................dont do this procedure.
>
>
>
> Thanks,
>
> Bill Leonhardt
>
>
Wait a minute guy's. Why the big no-no on crimping the wires to extend
them?
I ask this since it was last year when I purchased an emergency generator
and asked here about how they wire up the CB panels for the generators and
... asked the local utility for advice.
Both came back with using wire nuts inside the panel was ok and per code.
This is the same thing electrically and using wire nuts - not crimp-ons and
special crimpers.
So did the world change while I wasn't looking?
Bob S.
"James D Kountz" <[email protected]> wrote in message
news:[email protected]...
>
> > Last week I had the Electrical Inspector at my house to check on the
> central
> > air conditioning which I had installed at the end of last summer.
>
> Its scary when people like this have inspectors jobs.
>
> > My questions then to the learned members of this group:
> >
> > 1. Do you agree that moving of the hi-load breakers to the
top
> of
> > the box will really minimize the lights dimming when their loads come
on?
>
> Horse-hockey. If your lights dim when something kicks on or off then the
> light circuit itself is a little overloaded to start with or you've got
some
> connections that arent as good as they should be. Ex. too many lights on
one
> circuit, other items on the circuit with the lights that shouldnt be like
> receptacles, disposals, dishwasher and such, wire size too small or
breaker
> too small for the said circuit. I have a simliar setup to the one you
> described and my lights never dim. Even with machines going in the shop,
> central air in the house, electric water heater and so on.
>
> >
> > 2. If true then I will move some existing breakers. To do so, I
will
> > have to extend the black wire on some 15 and 20 amp breakers. Are
> crimp-on
> > splices acceptable for this?
> >
>
> A big no no. If you still want to do this procedure and the wires arent
long
> enough then..................dont do this procedure.
>
>
>
> >
> >
> >
> > Thanks,
> >
> > Bill Leonhardt
> >
> >
>
>
1. <<<<< Do you agree that moving of the hi-load breakers to the
top of
>>>>>>>the box will really minimize the lights dimming when their loads come
on?
I have hot experienced this my self, but have read it at other forums. FWIW
Tony D.
"Bill Leonhardt" <[email protected]> wrote in message
news:[email protected]...
> Sorry if you see this twice. I didn't see it make it out the first time.
>
>
>
> Last week I had the Electrical Inspector at my house to check on the
central
> >>>>>>>>Snip>
Bill,
Buy a hard-start capacitor for your AC compressor. My old unit was
causing no problems, but when I bought a new AC unit, the house lights
would nearly go OUT when it kicked in. I checked all the connections
and everything was OK. I went to an AC supply house and bought an
add-on capacitor. I think it was less than $20. It's about the size
of an orange juice can with several wires sticking out one end. It
comes with layman's directions to hook it up to the compressor wiring.
Now I get just a tiny flicker of the lights.
DonkeyHody
"Bill Leonhardt" <[email protected]> wrote in message news:<[email protected]>...
> <Greg G.> wrote in message
> news:[email protected]...
> > LRod said:
> >
> > >I'm always amused by this topic, especially when perpetuated by people
> > >who should know better.
> >
> > As my follow up to this stated:
> >
> > "Some of the cheap contractor-pack load panels are marginal affairs,
> > and the bus bars are barely adequate for the loads they are rated at.
> > A high quality service panel *should* show no improvement from this.
> > But in theory and practice, there are valid reasons for doing so."
> >
>
> I'm the O.P.
>
> First, thanks for all the replies thus far. I'm definitely gonna avoid
> splices.
>
> A little more background:
> 1. I have 200 amp service. The main panel, which is new (1.5 years old),
> was installed after a "whole house" renovation. The panel is the Square D
> "home special" (I think that's the name) you see at the Borg. It could have
> a "thin" buss.
> 2. I have all new circuits, not heavily loaded, and had no dimming prior to
> the A/C installation.
> 3. The dimming I do get with the A/C starting is momentary, not continuous.
> 4. The A/C has a 50 amp double breaker.
>
> I appreciate LRod's point about the high conductance of the buss and then,
> theoretically the light circuits higher up from the A/C on the buss
> shouldn't be effected by the A/C. I can also kind of imagine that when the
> A/C starts, there is a voltage wave (like a pressure wave in piping) that
> might cause a "disturbance" in the circuits it passes in the main buss.
>
> For now, I'm gonna investigate where I have wire slack and consider, where
> possible, locating the higher load breakers higher in the box.
>
> Again, thanks to all who responded.
>
> Bill
Bill Leonhardt said:
>The inspector said to me that I might consider moving the higher amp
>breakers to the top of the box. That would minimize the lights dimming when
>these loads came on. My lights do dim a little when the A/C first starts
>up.
>
>My questions then to the learned members of this group:
>
>1. Do you agree that moving of the hi-load breakers to the top of
>the box will really minimize the lights dimming when their loads come on?
Absolutely! The closer to the main breaker the high load taps are
located on the buss bars, the better.
>2. If true then I will move some existing breakers. To do so, I will
>have to extend the black wire on some 15 and 20 amp breakers. Are crimp-on
>splices acceptable for this?
Not appreciated by some AHJ, and kind of sloppy. A better solution is
attempting to pull some slack from outside the box into the panel and
strip back a little more insulation. But if that can't be done...
FWIW,
Greg G.
<Greg G.> wrote in message
news:[email protected]...
> LRod said:
>
> >I'm always amused by this topic, especially when perpetuated by people
> >who should know better.
>
> As my follow up to this stated:
>
> "Some of the cheap contractor-pack load panels are marginal affairs,
> and the bus bars are barely adequate for the loads they are rated at.
> A high quality service panel *should* show no improvement from this.
> But in theory and practice, there are valid reasons for doing so."
>
I'm the O.P.
First, thanks for all the replies thus far. I'm definitely gonna avoid
splices.
A little more background:
1. I have 200 amp service. The main panel, which is new (1.5 years old),
was installed after a "whole house" renovation. The panel is the Square D
"home special" (I think that's the name) you see at the Borg. It could have
a "thin" buss.
2. I have all new circuits, not heavily loaded, and had no dimming prior to
the A/C installation.
3. The dimming I do get with the A/C starting is momentary, not continuous.
4. The A/C has a 50 amp double breaker.
I appreciate LRod's point about the high conductance of the buss and then,
theoretically the light circuits higher up from the A/C on the buss
shouldn't be effected by the A/C. I can also kind of imagine that when the
A/C starts, there is a voltage wave (like a pressure wave in piping) that
might cause a "disturbance" in the circuits it passes in the main buss.
For now, I'm gonna investigate where I have wire slack and consider, where
possible, locating the higher load breakers higher in the box.
Again, thanks to all who responded.
Bill
On Wed, 07 Jan 2004 15:10:43 -0500, Greg G. wrote:
>>1. Do you agree that moving of the hi-load breakers to the top of
>>the box will really minimize the lights dimming when their loads come on?
>
>Absolutely! The closer to the main breaker the high load taps are
>located on the buss bars, the better.
I'm always amused by this topic, especially when perpetuated by people
who should know better.
Look at it this way: wire resistance is measured in Ohms/100 FEET. The
perfectly legitimate ampacity of 12 gauge wire is 20 amps. That safely
accommodates a circuit length of dozens of feet at that current load.
I don't know the exact cross sectional area of a typical bus in a 200
amp/40 slot load center, but it is a WHOLE bunch more than even 10
times that of 12ga. wire. And it's only a matter of inches long
(probably 18 or less).
I don't think it would be possible to measure the voltage drop on a
typical 18" bus at 1000 amps, much less 100 or 50. You certainly
wouldn't be able to solve light dimming by whatever insignificant
amount it is.
I was shocked (sorry) when I read the recommendation to put the higher
current breakers farther up the bus in a how-to electrical book by a
very respected author. He should have known better.
LRod
Master Woodbutcher and seasoned termite
Shamelessly whoring my website since 1999
http://www.woodbutcher.net
Greg G. said:
>Bill Leonhardt said:
>
>>The inspector said to me that I might consider moving the higher amp
>>breakers to the top of the box. That would minimize the lights dimming when
>>these loads came on. My lights do dim a little when the A/C first starts
>>up.
>>
>>My questions then to the learned members of this group:
>>
>>1. Do you agree that moving of the hi-load breakers to the top of
>>the box will really minimize the lights dimming when their loads come on?
>
>Absolutely! The closer to the main breaker the high load taps are
>located on the buss bars, the better.
I should add that is hardly worth the trouble in an existing box if
the wiring isn't long enough to reach. This is something that is best
done when the panel is first installed and wired. Some of the cheap
contractor-pack load panels are marginal affairs, and the buss bars
are barely adequate for the loads they are rated at. A high quality
service panel *should* show no improvement from this. But in theory
and practice, there are valid reasons for doing so.
>>2. If true then I will move some existing breakers. To do so, I will
>>have to extend the black wire on some 15 and 20 amp breakers. Are crimp-on
>>splices acceptable for this?
>
>Not appreciated by some AHJ, and kind of sloppy. A better solution is
>attempting to pull some slack from outside the box into the panel and
>strip back a little more insulation. But if that can't be done...
If you cannot rearrange things without splicing, I wouldn't do it. As
mentioned, many AHJ frown on this practice. The lesser of the two
evils is leaving things as they are. You need heavy crimp ferrules
and a tool to install them with. Then you have to worry about the
connection's integrity and the insulating tape unraveling if you don't
use good heat-shrink tubing.
Greg G.