# "Hot" Neutral



## MDShunk (Jan 7, 2007)

1) Most home inspectors are retards who washed out of real jobs.
2) How hot is hot? The conductor insulation rating is pretty darned high, so it can get hot and tolerate it. 

Having said that, make sure that any MBWC's didn't get put on the same phase over the years and check to make sure everything is tight on the neutral bar (including service neutral).


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## 480sparky (Sep 20, 2007)

"Hot" is a relative thing.

I've had customers complain about dimmers being hot to the touch. I shoot them, and they're 110°F. They still worry it will start a fire. I reply, "If 110 degrees will start a fire, the entire state of Arizona will spontaneously combust every summer."

Personally, I'd be more worried about the 175° air in the ducts when the firnace is running.

ALL wiring and equipment under load will heat up. Heat is a by-product of current flow. Nothing more.

I'd ask for the HIs credentials.


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## MDShunk (Jan 7, 2007)

If you find everything "normal" just tell them you tightened something. No sense getting in a pissing match with the homely spector.


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## TOOL_5150 (Aug 27, 2007)

MDShunk said:


> 1) Most home inspectors are retards who washed out of real jobs.


Agreed 

Worst $480 I EVER spent.


He found that my toilets wobbled but didnt bother to go in the attic to tell me mice/rats had devoured lots of romex sheath!

~Matt


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## John (Jan 22, 2007)

MDShunk said:


> If you find everything "normal" just tell them you tightened something. No sense getting in a pissing match with the homely spector.


And....
"Breakersize" the circuit breakers by turning them on and off a couple times. This gives the people watching the impression that you are doing something for the money that you are charging for the service call. :whistling2:
And as Marc said check to make sure everything is tight.

Carry On....that is all.


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## Toronto Sparky (Apr 12, 2009)

Prob. overloading the neutral with all the new non-linear loads such as CFLs and such.. 
Sure no one thought about that.. Tunnel vision .. SAVE POWER. Just a thought.


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## 480sparky (Sep 20, 2007)

If the neutral is overloaded because of a MWBC installed on a tandem breaker, that is the problem.

Of course, we can't expect a HI to understand MWBCs on piggybacks. :thumbsup:


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## Zog (Apr 15, 2009)

Jupe Blue said:


> Got a call from a good customer (residential) today. Says that he had a home inspector who wrote in his report that upon using a digital laser thermometer on the service panel, that the neutrals were "hot" (temp. wise, not electrically speaking). Wants to schedule me out to take a look and will show me the written report when I arrive. So, my questions:
> 
> What would be a "hot" temperature to read off a breaker, feeder or other conductor? Would the temp be relative to ambient temperature or relative to temps on components of the panel? At what temps. should I be concerned?
> 
> ...


Well a laser thingy isnt worth the $20 he paid for it but here are the recommened actions from an IR survey


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## 480sparky (Sep 20, 2007)

Zog said:


> Well a laser thingy isnt worth the $20 he paid for it but here are the recommened actions from an IR survey


Gee, did I get ripped off. I paid $875 for mine.


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## Zog (Apr 15, 2009)

480sparky said:


> Gee, did I get ripped off. I paid $875 for mine.


Still worthless in this application. Only tells a small part of the story. Dont get me wrong, I have one too, but it is nothing like an IR camera in the hands of a certified thermographer.


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## Kevin J (Dec 11, 2008)

Zog said:


> Still worthless in this application. Only tells a small part of the story. Dont get me wrong, I have one too, but it is nothing like an IR camera in the hands of a certified thermographer.



Care to elaborate? I'm having trouble trying to figure out why a laser thermometer is worthless in this application. NASCAR mechanics use them all the time to temp various engine parts; they don't use IR cameras for this. Don't get me wrong, I think IR cameras are great, but sometimes its a little overkill.


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## MDShunk (Jan 7, 2007)

Toronto Sparky said:


> Prob. overloading the neutral with all the new non-linear loads such as CFLs and such..
> Sure no one thought about that.. Tunnel vision .. SAVE POWER. Just a thought.


You'll never in your career see a neutral overloaded because of that.


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## 480sparky (Sep 20, 2007)

Zog said:


> Still worthless in this application. Only tells a small part of the story. Dont get me wrong, I have one too, but it is nothing like an IR camera in the hands of a certified thermographer.


And there are apps that an IR camera is worthless, and an IR t'meter will rule.


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## Zog (Apr 15, 2009)

Kevin J said:


> Care to elaborate? I'm having trouble trying to figure out why a laser thermometer is worthless in this application.


Just tells you something is hot, you dont know what so comparing those values to ambeient or other equipment and using that ifo to make any recomendation is worhless. Reflection, radiation, etc can all effect those readings. 



Patrik2075 said:


> NASCAR mechanics use them all the time to temp various engine parts; they don't use IR cameras for this.


What dies that have to do with the price of rice in China? Or electrical equipment evaluation for that matter?


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## 480sparky (Sep 20, 2007)

Zog said:


> Just tells you something is hot, you dont know what so comparing those values to ambeient or other equipment and using that ifo to make any recomendation is worhless. Reflection, radiation, etc can all effect those readings.
> 
> 
> 
> What dies that have to do with the price of rice in China? Or electrical equipment evaluation for that matter?


 
So an IR camera tells me a lug is 238°F, and an IR thermometer tells me it is 238°F. What's the difference?


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## MDShunk (Jan 7, 2007)

480sparky said:


> So an IR camera tells me a lug is 238°F, and an IR thermometer tells me it is 238°F. What's the difference?


Ambient compensation on the IR camera is pretty handy. They were demo-ing some IDEAL IR cameras at the supply house today. They looked like toys.


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## 480sparky (Sep 20, 2007)

MDShunk said:


> Ambient compensation on the IR camera is pretty handy. They were demo-ing some IDEAL IR cameras at the supply house today. They looked like toys.


Is _ambient compensation_ the same thing as _emmisivity_?


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## Jupe Blue (Aug 18, 2008)

Toronto Sparky said:


> Prob. overloading the neutral with all the new non-linear loads such as CFLs and such..
> Sure no one thought about that.. Tunnel vision .. SAVE POWER. Just a thought.


The job that I did most recently for this customer was to install a high end lighting system (Control 5). Replaced 120 switches with very expensive ($100 each) that are computer controlled. It's the kind of system where you can turn your lights on from the office, set multiple lighting scenes, etc. Sold to the customer by a local high end AV company. I did the install of the switches only. The AV company did all the programming. Am being called back now (a year later) to replace 6-8 of them and also check out the "hot" neutral. 

I'll let you know if the 'hot' neutral is associated with the lighting circuits.


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## steelersman (Mar 15, 2009)

480sparky said:


> If the neutral is overloaded because of a MWBC installed on a tandem breaker, that is the problem.
> 
> Of course, we can't expect a HI to understand MWBCs on piggybacks. :thumbsup:


Maybe I'm wrong but I don't think that an overloaded neutral on an improperly installed MWBC will cause the main neutral to overheat. They have nothing to do with each other in that regard.

After re-reading the OP I see that he isn't necessarily talking about the main neutral. Sorry. Thought he was.


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## 480sparky (Sep 20, 2007)

steelersman said:


> Maybe I'm wrong but I don't think that an overloaded neutral on an improperly installed MWBC will cause the main neutral to overheat. They have nothing to do with each other in that regard.
> 
> After re-reading the OP I see that he isn't necessarily talking about the main neutral. Sorry. Thought he was.


OP never said it was the main noodle. We do, however, have these morsels of information:



Jupe Blue said:


> ............that the neutrals were "hot"......





Jupe Blue said:


> ............I'll let you know if the 'hot' neutral is associated with the lighting circuits.


I'd say we're looking a branch circuits at this point.


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## steelersman (Mar 15, 2009)

480sparky said:


> OP never said it was the main noodle. We do, however, have these morsels of information:
> 
> 
> 
> ...


sorry big dog. I jumped the gun. You can see I went back and edited it. It was like one of those deals where as soon as you click send you wish you could grab it and take it back. I've shot off a few e-mails like that in the past where as soon as I hit send I wanted it back.


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## Zog (Apr 15, 2009)

480sparky said:


> And there are apps that an IR camera is worthless, and an IR t'meter will rule.


Agreed, I never said otherwise.


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## 76nemo (Aug 13, 2008)

480sparky said:


> Gee, did I get ripped off. I paid $875 for mine.


 
$875, good gosh. What make and model did you purchase Ken? I paid $3+ for what I thought I needed. Works for me.


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## 76nemo (Aug 13, 2008)

Kevin J said:


> Care to elaborate? I'm having trouble trying to figure out why a laser thermometer is worthless in this application. NASCAR mechanics use them all the time to temp various engine parts; they don't use IR cameras for this. Don't get me wrong, I think IR cameras are great, but sometimes its a little overkill.


 
Apples and oranges to say the least in this scenario.


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## 76nemo (Aug 13, 2008)

480sparky said:


> And there are apps that an IR camera is worthless, and an IR t'meter will rule.


 
Are you talking about PM specifically? Can you elaborate some more?


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## 480sparky (Sep 20, 2007)

76nemo said:


> Are you talking about PM specifically? Can you elaborate some more?


Yes. IR cameras cannot plot temp changes over time.












76nemo said:


> $875, good gosh. What make and model did you purchase Ken? I paid $3+ for what I thought I needed. Works for me.


You paid three bucks for an IR thermometer?

I got a Raynger MX4+. It's now the Fluke 574.


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## 76nemo (Aug 13, 2008)

480sparky said:


> Is _ambient compensation_ the same thing as _emmisivity_?


 
Not at all, I'll come back to that.


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## 76nemo (Aug 13, 2008)

On the subject of emmisivity, what exactly was the home inspector shooting?????? There are many angles here with some home pro joe using an infared thermometer. If he wanted to include these types of "overheating" issues in his report, he should be using a surface type contact probe so discussions like this he could avoid


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## 480sparky (Sep 20, 2007)

Another way IR t'meters outshine IR cameras............

Probes. Means you can take the temp of the _insides_ of certain things.


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## 76nemo (Aug 13, 2008)

480sparky said:


> Another way IR t'meters outshine IR cameras............
> 
> Probes. Means you can take the temp of the _insides_ of certain things.


 
Gotcha. I wasn't speaking for probe measurement, just surface scanning.


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## 76nemo (Aug 13, 2008)

*Emissivity*

http://en.wikipedia.org/wiki/Emissivity


With thermal imaging and what Marc spoke of as far as ambient compensation, you can clearly see how another component or conductor relates to the scan as a reference to what you are looking at ambient wise. An IR thermometer can't do that. You'd be seeing every single different spot ratio by a somewhat different reference or angle with an IR thermometer. With imaging, you see the picture or area as a whole.

Zog agreed with you that an IR thermometer could outway a thermal scan in certain scenarios, that I don't understand unless it's from a budget standpoint or a VERY specific PM schedule.

Both IR thermometers and imagers deflect on emissivity, and both are handled in the same manner.


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## 76nemo (Aug 13, 2008)

"You paid three bucks for an IR thermometer?

I got a Raynger MX4+. It's now the Fluke 574. "



Really nice gun Ken!!!!!! I think I paid $3.80 for my gun but I got it for $1.50 discount:thumbsup:


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## 480sparky (Sep 20, 2007)

76nemo said:


> "You paid three bucks for an IR thermometer?
> 
> I got a Raynger MX4+. It's now the Fluke 574. "
> 
> ...


 
This t'meter can also log up to 100 data points at a time. You can then download them onto a computer, and compile a PM log over time to watch for sudden changes in temperature. In other words, instead of it monitoring a point all the time, like the graphic I posted, you can shoot it at regular intervals and compile a graph spaced out over a much longer time frame.

If I think about it tomorrow, I'll download some off my laptop and try to post them.

I'm curcious, however, where you got a $3 IR thermometer.


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## 76nemo (Aug 13, 2008)

480sparky said:


> This t'meter can also log up to 100 data points at a time. You can then download them onto a computer, and compile a PM log over time to watch for sudden changes in temperature. In other words, instead of it monitoring a point all the time, like the graphic I posted, you can shoot it at regular intervals and compile a graph spaced out over a much longer time frame.
> 
> If I think about it tomorrow, I'll download some off my laptop and try to post them.
> 
> I'm curcious, however, where you got a $3 IR thermometer.


 
$380, $150 discount. SmartSensor AR862A.

Similiar to the Fluke 568, yet no logging capability or tripod mount.


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## 76nemo (Aug 13, 2008)

It has the laser point feature unlike the 568. It was a $530 gun, but I eyeballed it at the right time.

What do you think of your gun Ken??? Do you use it often? Do you have service contracts you use it for commercial/industrial sites quite often Ken????


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## Jupe Blue (Aug 18, 2008)

*Here's what I found*

Went to trouble shoot the "hot" neutral today. 

First here is the verbatim report from the home inspector:

"There was a significant temp. rise in breaker #11 in Panel "B". The ambient temp. of the breakers in the panel was about 65 degrees. The A and B breaker of #11 is 100 degrees.

The wiring of these two circuits are also elevated in temp. which is indicating that there is a draw on the circuit rather than just in the breaker. The neutral wire on the master bedroom circuit also has an elevated temp. in addition to the temp rise on the "hot" wiring, which may indicate that there is a damaged or shorting ground.

It is normal and expected to have some variation in the temperatures of the breakers, however any variation over 7 degrees in considered significant and over 10 to 15 degrees is considered to be excessive. Electrical resistance builds up heat. These temp. increase can be an idicator of anything from bad/defective breakers, shorting circuits, over loaded circuits, or even failing appliances. It would e recommended to have a licensed electrician investigate this temp. variance and repair deficiencies in the electrical system."

The homeowner also reports that the when the cleaning crew run their vacuum on the master bedroom plugs the circuit 11b trips and sometimes trips when all the lights on this circuit are on.

I turned on all the lights on the circuit and took a reading with my amp. probe. Circuit was drawing ~19-20 amps. It tripped approx. 5-8 minutes after all lights were energized. It also showed a temp. increase from 74 degrees to 84 degrees using a Fluke digital laser thermometer.


Circuit 11b (15 amp) is the lighting circuit for the 1/2 of the garage, entry hall, master bath, dressing area and balcony lights. It is also the plug circuit for some of the master bedroom plugs. 

I did a rough addition of the existing lighting load which came to 2440 watts. 

My plan run an additional 15 amp. circuit to split the second floor part of the circuit and decrease the lamp size in the vanity lights (currently 10 lamps @ 75 w. each) to bring the lighting load down to about 1500 watts. And tell the cleaning people to plug into the bath GFCI for running the vacuum.


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## Richard Rowe (May 25, 2009)

Just wondering, what was the size of the wire on the circuit? Have you added the new circuit yet? If so please post your results.


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## Jupe Blue (Aug 18, 2008)

Haven't been back to split out the circuit. The wire is #14 on a 15a "twin" GE breaker. Left strict instructions with the HO and his wife not to turn on all the lights at the same time!


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## Jupe Blue (Aug 18, 2008)

Went back last week. Split the circuit putting the bath and dressing lights on the new circuit. Left the hall and garage on the original circuit. Was definately a 15A breaker with #14 wire.


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## scruffy (Aug 7, 2009)

Try asking the inspector did he check for loose set screws or lugs,temp of the mains including neutral as compared to the branch ccts the breaker it self and the attachment points of the breakers or fuses to branch cct conductors or the same but the attachment to the main bus bars of the panel.Also the best way to see what's going on is to hook up a power analysis meter you can see the everything you could possiably imagine.


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## sparks134 (Jan 30, 2009)

Mwbc?


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## B4T (Feb 10, 2009)

Multi Wire Branch Circuit


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