# Dimming lights



## Vintage Sounds (Oct 23, 2009)

Investigate the neutral for corrosion, poor connection, etc.


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## 3DDesign (Oct 25, 2014)

Like Vintage said, Neutral could be loose in the panel, at meter outside, at point of attachment, or even at the pole.


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## akheilman (Jun 28, 2011)

Vintage Sounds said:


> Investigate the neutral for corrosion, poor connection, etc.



Is it most likely an issue with the neutral of the circuit that is dimming? Both the dining room chandelier with incandescent lamps and the kitchen lighting circuit with LED lamps have the dimming issue. The thing is that these two lighting circuits are desperate circuits.


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## akheilman (Jun 28, 2011)

3DDesign said:


> Like Vintage said, Neutral could be loose in the panel, at meter outside, at point of attachment, or even at the pole.



You feel that it's the main neutral somewhere rather than the circuit neutral?


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## 220/221 (Sep 25, 2007)

What is the current draw on the machine? 



Since it is less noticeable when the AC is off, I suspect it's system wide and maybe/probably on the the POCO end.

If there are multiple panels involved, run a #12 extension cord to the main service panel and see it it corrects the problem.



> At the panel that the kitchen receptacles are fed from, the SABC feeder leg drops 2 volts upon turning the espresso machine on. The opposite leg increases 2 volts at the same moment.


2 volts doesn't seem like much but the up/down voltage is typical of a compromised neutral.


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## akheilman (Jun 28, 2011)

220/221 said:


> What is the current draw on the machine?
> 
> 
> 
> ...



The machine is 14.5A. Good idea; I'll try the extension cord.


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## TTW (Sep 14, 2012)

Neutral, Neutral, Neutral.

Think possibly a problem from the pole to the panel, maybe even corrosion at the meter connections.


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## 220/221 (Sep 25, 2007)

TTW said:


> Neutral, Neutral, Neutral.
> 
> Think possibly a problem from the pole to the panel, maybe even corrosion at the meter connections.


Or at the sub or the sub feeder.

Plugging it in to the main panel will narrow it down.


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## TTW (Sep 14, 2012)

Wow, if that puppy draws 14.5 amps methinks these folks are just way too addicted to caffeine...

I do like the idea of going straight to the panel with an extension cord, and if everything is good that way, I would consider a dedicated espresso receptacle.

There's got to be a good joke in here somewhere, ...


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## Skooby (May 3, 2012)

Almost every time I hear symptoms like this, it is a bad N connection on poco side of meter...


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## MDShunk (Jan 7, 2007)

I think everyone is barking up the wrong tree when they keep saying neutral. If that was the case, other lights would also get brighter. In this case you're either looking for a bad service HOT conductor, undersized/corroded service drop/lateral, or an undersized/overloaded pole top transformer. The neutral is fine, and it's the hot legs you need to look at. Something service equipment/service side related on the hots.


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## Moonshot180 (Apr 1, 2012)

Way back in my apprentice days, when industrial and commercial was slow, we would wire homes, and some of them, (especially in the higher end neighboorhoods) would have us run 500mcm drops, in an effort to eliminate flicker, when high amperage loads would in the home would cycle on/off.


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## 220/221 (Sep 25, 2007)

MDShunk said:


> I think everyone is barking up the wrong tree when they keep saying neutral. If that was the case, other lights would also get brighter.


Maybe they are but it is not as evident or visable like the chandilier?


Do you think the 2V plus on one side and 2V minus on the other leg is normal/inconsequential? 

I'm not sure at what voltage it becomes a problem. We have all seen the neutral related 10-20 volt change and it's enough to dim/brighten the lights and turn off the TV. 

@ 2V? I have no clue :no:


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## pete87 (Oct 22, 2012)

The reason I always run Chandeliers on its own circuit , 10 or 12 bulbs . What is the wattage ? It can add up quickly .

Coffee Maker is a big draw , like to see its own circuit .

I agree that it is not likely a neutral problem .




Pete


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## dmxtothemax (Jun 15, 2010)

Does the chandelier still dim
If you bypass the dimer ?
I have come across simulair problems
Caused by non linear response 
From the dimers control circuitry.


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## akheilman (Jun 28, 2011)

dmxtothemax said:


> Does the chandelier still dim
> If you bypass the dimer ?
> I have come across simulair problems
> Caused by non linear response
> From the dimers control circuitry.



I bypassed the dimmer and the dimming continued.


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## akheilman (Jun 28, 2011)

pete87 said:


> The reason I always run Chandeliers on its own circuit , 10 or 12 bulbs . What is the wattage ? It can add up quickly .
> 
> 
> 
> ...



I would say that they are 25W bulbs; I will check when I am back there on Monday. The coffee maker was basically on its own circuit as it is on the kitchen SABC and nothing else was plugged into that circuit.


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## dawgs (Dec 1, 2007)

....


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## akheilman (Jun 28, 2011)

dawgs said:


> ....



That's all you have to say? [emoji15]


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## RIVETER (Sep 26, 2009)

akheilman said:


> I had a call recently to inspect some dimming lights in a home. It started when they purchased a new coffee espresso machine to replace their old one. When the unit is turned on and is hearing the water and the Central A/C unit is running the lights in the house start dimming. 90% of the house is LED lamps and they do not show quite as much dimming. The worst of the dimming is a 10 or 12 lamp incandescent chandelier in the dining room off the kitchen. The espresso machine causes dimming regardless of which 20A small appliance branch circuit is used in the kitchen. All the lighting is on separate circuits from the kitchen counter receptacles. All feeder hots & neutrals appear tight and unoxidized. All branch circuit connections in all panels are tight. At the panel that the kitchen receptacles are fed from, the SABC feeder leg drops 2 volts upon turning the espresso machine on. The opposite leg increases 2 volts at the same moment. The dimming is much less noticeable when the central A/C is not running. The legs at the service and panels are at 115V & 117V. Any thoughts on the cause of this?


Plug two hair dryers into the same 20 amp receptacle and see if the results are the same. Of course...turn them on max..


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## akheilman (Jun 28, 2011)

RIVETER said:


> Plug two hair dryers into the same 20 amp receptacle and see if the results are the same. Of course...turn them on max..



Actually, there was some other work being done on the house and the guys were using a power saw that was causing the same results. The circuit the saw was running on came from a different circuit in a different panel.


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## RIVETER (Sep 26, 2009)

akheilman said:


> Actually, there was some other work being done on the house and the guys were using a power saw that was causing the same results. The circuit the saw was running on came from a different circuit in a different panel.


Was the circuit that the circular saw was on involved with the circuit you are wondering about...as in MWBC?


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## akheilman (Jun 28, 2011)

No, all circuits in the house appear to be single, dedicated neutral circuits.


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## RIVETER (Sep 26, 2009)

akheilman said:


> No, all circuits in the house appear to be single, dedicated neutral circuits.


Okay, then, bad bearings on the circular saw..


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## Wireless (Jan 22, 2007)

RIVETER said:


> Okay, then, bad bearings on the circular saw..


Or it's the only MWC! The service!


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## akheilman (Jun 28, 2011)

Wireless said:


> Or it's the only MWC! The service!



That's an interesting way to think of it, and I think you're right. I was at the job yesterday and took more measurements than I can remember. From what I can tell the issue is outside the house. One thing I noticed was the aerial span to the house. It looks like t was either chewed or severely scraped by branches. It appears that the aluminum is missing in some areas and all that is left is the steel core.


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## 220/221 (Sep 25, 2007)

Well, there ya go.

Out here, we always have them call POCO first on calls like this.


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## akheilman (Jun 28, 2011)

220/221 said:


> Well, there ya go.
> 
> 
> 
> Out here, we always have them call POCO first on calls like this.



Well I learned the hard way; or they did, but now I know. Thanks for all the help guys.


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## FF301 (Jan 12, 2014)

Remember this and learn. 
Glad you found problems cause
99% of the time you have voltage drop on one leg and voltage rise on the other it's the main N
Loading does not cause voltage rise


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