Lights Getting Brighter - Possible Loose Neutral?

Thread Starter

mostlydrummer

Joined Feb 8, 2016
19
"After a couple of hours, I finally gave up, turned the thirteen overhead lights back on, and shut the fridge door. Within 15-20 seconds, the compressor kicked in,"

The compressor may be designed to only come on when the door is closed.

Are the lights LEDs?
Good thought, and agreed - I considered that and as noted above tried with the door both open and closed (and both for extended periods) with the main dimmer off. No compressor.

The lights are incandescent.

Thanks.
 

Thread Starter

mostlydrummer

Joined Feb 8, 2016
19
DGElder, unfortunately I'm not checked out on a multimeter...

Regarding your additional comment about the dimmer, they were not the same type of dimmer (both Lutrons, but the original one was a completely different model and much more complex).

It does seem as if a possible next step would be to bypass the dimmer with a regular switch, although it still seems weird that what you describe would impact lights and fridge on separate circuits (albeit one with adjacent breakers on the panel). No other lights in the house brighten when this compressor comes on, and these lights don't brighten when another refrigerator or other motors elsewhere in the house turn on.
 
Late for the party...sorry.

The pics were too microscopic. Could not see the "big picture"..Saw white wires connected to a "green" bus.


The general deal is:
neutral and ground connect at one spot, and it's the panel that the meter feeds. I'll use ground here. The EARTH connection is also made here. In older homes, earth may be provided by copper pipe. It is in my house.
The copper pipe does do some under the slab meanderings too and not too far from the panel.

What created problems for some people is when the previous metal meter got replaced with plastic. So, you have to watch for that, Ground straps should be in place across the meter in this case.

So, this system doesn't have ground rod. Copper pipe will be tied to this bonded connection too just to make the fixtures at the local Earth potential.

he sub-panel which looks like a main-lug panel should have ground, neutral, L1 and l2 as totally separate wires.
bare and greens should only goto green and neutrals only to neutrals. The neutral bus and the ground bus is not connected in this panel. It is connected at the panel where the meter feeds,

Locally that fridge circuit might dip and locally the INPUT to the dimmer may dip in voltage. That's places I would look. So, I would expect a dip, but I wouldn't want one. SO, it's like how far does the dip go?

Possible reason: Breaker feeding the sub panel has a high resistance.

Now, we have a dimmer and let's say it's a smart dimmer. The dimmer sees the dip and tries to compensate, but it overcompensates instead meaning the lights get brighter.

So, a bypassed dimmer might not do a thing to the lights or they may dim.

So, you might be drawn away from the real problem by looking at the symptom.

Besides bypassing the dimmer, this http://www.idealindustries.ca/produ...cuit_analyzers/suretest_circuit_analyzers.php would be the tool (Ideal Sure Test) I might use. I have this particular tool.
 

cmartinez

Joined Jan 17, 2007
8,218
Possible reason: Breaker feeding the sub panel has a high resistance.
It is possible... but in that case the breaker would warm up and quite possibly trip.
On the other hand, modern breakers are designed to be installed and removed with a snap type of mechanism. If that mechanism is not perfectly tight it could explain the whole thing.
I suggest you check the breaker box by tugging each one back and forth, see if any of them (perhaps even the main one) is loose.
 

Thread Starter

mostlydrummer

Joined Feb 8, 2016
19
Then how do you expect to find a voltage variation or a high resistance connection?
This Thread has been going on for 2 months. Have you inspected every inch of the neutral wire yet?
AAC, I don't necessarily expect to find a voltage variation or a high resistance connection as I don't necessarily know those are the problems and I'm not qualified to test those things myself. It should be clear that I'm neither an electrician nor an advanced hobbyist. I joined this forum to try to gain some insight from people more knowledgeable than I because two licensed and well-regarded electricians have been unable to troubleshoot this problem. I think I've done a reasonably good job of laying out the facts and the conditions I've observed in a logical manner that would potentially allow someone more knowledgeable than I to offer some suggestions as to how to proceed, either myself (in the case of some suggestions that have helped to isolate aspects of the system's behavior) or with an electrician (in the case of things I'm not qualified to do myself). And I appreciate people's helpful suggestions.

Of course I haven't inspected every inch of the neutral wire, because some of it is (obviously) buried in the wall. Troubleshooting, naturally, moves along a rational course from most obvious and least difficult to less obvious and more difficult. We're somewhere in that continuum now and continuing to progress. If you feel this thread has been under discussion for two long and that I'm not moving fast enough for you, then it's certainly your choice not to read it.

For everyone else, thank you for your continuing suggestions, and please keep them coming!
 

wayneh

Joined Sep 9, 2010
17,496
Divide and conquer. You may want an electrician to make the changes, but I'd start trying to isolate the lines that have the alleged problem. (I say alleged because I still don't see what the problem is.) You should be able to move circuits around until you have a problem isolated to just one circuit leaving your breaker box. Separate it from the good ones to get it onto its own breaker. I think I'd buy and install a new breaker and start moving wires off the goofy one, looking for changes in the symptoms as I went.
 

cmartinez

Joined Jan 17, 2007
8,218
Divide and conquer. You may want an electrician to make the changes, but I'd start trying to isolate the lines that have the alleged problem. (I say alleged because I still don't see what the problem is.) You should be able to move circuits around until you have a problem isolated to just one circuit leaving your breaker box. Separate it from the good ones to get it onto its own breaker. I think I'd buy and install a new breaker and start moving wires off the goofy one, looking for changes in the symptoms as I went.
good 'ol trial and error... a little time-consuming, but effective
 

Thread Starter

mostlydrummer

Joined Feb 8, 2016
19
Almost a year later, new developments but incomplete resolution...

Brief recap:

- Basement overhead can lights on a circuit that is adjacent to the circuit with basement outlets get brighter when the compressor kicks in on a small refrigerator that is plugged into one of the outlets.
- Power company has checked pole connection and both sides of meter connection.
- All basement circuits (as well as a lot of others) are on a subpanel that is connected to the main panel.
- Three electricians (and now four, see below) have performed various levels of troubleshooting in search of a loose neutral and nobody has found anything. The "problem" persists.

So late last summer, we kicked off a major kitchen renovation that impacted other parts of the house as well, and since that time we've basically been shut down in the basement until a couple of weeks ago. When I reconnected my stereo (which has several big amps and power supplies) in the basement to one of the outlets (same circuit as the fridge), I noticed that it made the overhead lights brighten when the power supplies kicked in. I hadn't noticed this before, but I'm sure it happened and I just didn't notice it. I also noticed that when I plugged a microwave that we had stuck in the basement to get out of the way into an outlet on the same wall as the fridge, it also made the overhead lights brighten.

I got to know an electrician pretty well during our kitchen project and appreciated how conscientious he is, so now that we were clear of the big project I asked him to take a look at this. He ran a new neutral from the panel for the outlet with my stereo and put it on a separate breaker (to protect the power supplies if there is a loose neutral). The stereo no longer affects the overhead lights. He also ran a new neutral from the panel for the outlet with the fridge and put it on a separate breaker (to isolate the fridge). The fridge no longer affects the overhead lights. The microwave, however, when plugged into one of the outlets on the "original" circuit, still makes the lights brighten. He tried the microwave from a separate outlet in the bathroom (same branch circuit), and it still made the lights brighten.

He checked the panel and subpanel, and traced all of the wires through every outlet, light switch, can fixture and junction box and found no evidence of a loose neutral. Interestingly, I just observed that the breakers for the new dedicated circuits with dedicated neutrals for the stereo and the fridge are on the opposite side of the panel from the adjacent breakers for the circuits for the overhead lights and the basement outlets, which he indicated share a neutral (maybe that's obvious/understood if the circuits are adjacent, but it's not to me).

So I'm stumped again, and based on what I've read, it's just really not ideal to have lights brightening because it suggests a potentially dangerous loose neutral. Do any of these changes and new facts suggest anything to anyone here? Thanks!

 

BillB3857

Joined Feb 28, 2009
2,570
The only thing I can think of is that somewhere along the way, there is a splice in the neutral that is not solid. This can sometime happen if two outlets are daisy chained, i. e. breaker box, outlet, outlet. I have seen that problem happen when the outlets are wired by use of the push-in holes in the back rather than the screw terminals on the side.
 
Old thread so necromancy in 3,2,1...
I came here looking for direction to my issue which is identical to OPs. The problem was worse on mine because it was a whole house tea party. The lights in the kitchen would brighten and stay until the fridge would cycle off. It also happened when placing a heavy load like a space heater, hair dryer, etc. I suspected a power spliced into a neutral on a switch somewhere (I ran across that once with no breaker trip). So first question to home owner; Any recent electrical work?- No. Any burned out plugs or discolored plates?- No. Which rooms started with this problem?- All started simutaneously getting worse with time. ???? Last night the wife felt electric jolts in the shower. Aha! A starting point. Grounding cable loosely wrapped on a wire protector that went a few inches into the ground. New grounding rod 6.5 feet in did not solve brightening or dimming, only shocking.
Testing showed 156 volts on one bolt 82 volts on the other when heavy appliance was turned on. A beautiful 120/120 when appliance was off. Systematically loosened all neutral/ground pairs to no avail. Advised client that problem may be before the breaker box. Call utility and we'll proceed from there.
Client called me today at 3 saying that utility took blame for the problem so no charge. Wires from meter to breakers were not a single run but a two part go figure why deal. All was cleaned and tightened and client has been giddily washing clothes since then without a hiccup (washer had given up on 82 volts).
OP, your trouble might be on the lines feeding the subpanel. The way I would proceed is run resistance test on L1 to L1, L2 to L2, Neutral to Neutral. All should read the same (0 ohms). The one with a difference should be your suspect. Run a single line betwixt them and test. If it works, awesome. If no change, try the next bolt until it is fixed. Good luck.
 

jb18114

Joined Feb 2, 2018
8
I just wanted to thank everyone on the thread. I'm year into being an electricians helper and I took on a small side job. It's a remodel and one of the carpenters commented that the lights got brighter when saws and other high draw loads started up, which didn't make sense to me. I observed it, and noticed that it was happening on separate circuits. The home owner asked me to find out what was going on, so I googled and ended up here, where the first thing that some of you all mentioned was a loose neutral on the utility side of the meter. The home owner was reluctant to call them, so I checked the main breaker panel, which is a sub panel from the service entrance panel and meter. Looked like there might be corrosion on the incoming neutral, but when I checked it more closely it was just no-lox anti-corosion grease because of the aluminum wire. Cleaned and tightened it down anyway, still had flickering lights. So I went out to the service entrance panel and carefully opened the utility side, pre-meter (I've assisted in replacing ~15 of these so far, so I'm familiar with the dangers.) Anyway, I couldn't believe my eyes when I saw the incoming neutral wire with lug still attached had blown off of the bar it should be attached to. I'm trying to get a photo up but having a hard time getting it from my Iphone to macbook. Unbelievable. I don't have any idea what would cause this to happen?
 

jb18114

Joined Feb 2, 2018
8
Hmmm... And just left it like that? I've heard these panels are pretty bad quality and judging by this, I believe it now.

It brings up another question though. Does this mean that all the construction equipment in the house is now having their circuits completed through the ground wire?
 

cmartinez

Joined Jan 17, 2007
8,218
Does this mean that all the construction equipment in the house is now having their circuits completed through the ground wire?
Yes, apparently they are... funny thing, something quite similar happened to me a few weeks ago at a manufacturing facility... but in my case it was because the so-called technicians couldn't tell between the neutral and ground wires.
 

Reloadron

Joined Jan 15, 2015
7,501
Hmmm... And just left it like that? I've heard these panels are pretty bad quality and judging by this, I believe it now.

It brings up another question though. Does this mean that all the construction equipment in the house is now having their circuits completed through the ground wire?
That would be my thinking. Thanks for sharing the pictures. Just about when I figure I have seen it all something like this comes along. I have never seen a lug cooked off like that and between residential and industrial I have seen some strange things over more years than I care to count. Nice job of chasing things down too.

Ron
 

nsaspook

Joined Aug 27, 2009
13,079
Hmmm... And just left it like that? I've heard these panels are pretty bad quality and judging by this, I believe it now.

It brings up another question though. Does this mean that all the construction equipment in the house is now having their circuits completed through the ground wire?
Lets hope not but it's likely the grounding system is acting a a current conductor somewhere in the house via a ground rod to the utility ground at the pole or transformer.
http://www.thecircuitdetective.com/mnpn.htm
 
Top