House Voltage Issues

[sholling]

My knowledge of electrical theory is pretty limited so I thought I'd toss this out there before spending money on an electrician. The house was built to code in 1988 and uses 12ga copper throughout the house

1. Voltage to the street side of the meter is 120-121v.
2. Voltage to my main breaker with all breakers off is 116v.
3. Voltage to the buss bar with only the mains on is 116v.
4. Voltage to the buss bar with all breakers on is 116v.
5. Voltage to my power outlets is 111-116v with a normal load dropping to 110-115 under a good load.
6. The 15A breakers have never tripped so I can't picture the load being too great.

Ideas? Thoughts?

 

[highfigh]

My knowledge of electrical theory is pretty limited so I thought I'd toss this out there before spending money on an electrician. The house was built to code in 1988 and uses 12ga copper throughout the house

1. Voltage to the street side of the meter is 120-121v.
2. Voltage to my main breaker with all breakers off is 116v.
3. Voltage to the buss bar with only the mains on is 116v.
4. Voltage to the buss bar with all breakers on is 116v.
5. Voltage to my power outlets is 111-116v with a normal load dropping to 110-115 under a good load.
6. The 15A breakers have never tripped so I can't picture the load being too great.

Ideas? Thoughts?

I would bet that the connections where the cables are secured are either not tight or are corroded. You shouldn't lose 5 V in that short a distance. If you used the box as your ground reference, they may not have used compression connectors on the conduit and if they go underground, the moisture will have its way with any metal. The power company is supposed to supply 120VAC +/- 10% but the problem isn't on their end.

 

[sholling]

I'm starting to think you're right. I get some breathtaking electric bills yet other then my AV gear and a computer I shouldn't be drawing that much power. Every light in the house is florescent and I had the "builder" central AC replaced with with a high efficiency system. Heat, hot water and cooking are all gas. Could 10" of bad wire between the meter and the panel be losing 5V and converting a percentage of what I'm drawing to waste heat? I don't poke around on the hot side of the main so I'll have to bring in a professional to look at it. If I do I'll have a surge suppressor installed at the same time.

Just for grins I replaced the two 15A breakers that feed the wall plugs and split off the power circuits for the garage off to a new breaker of their own but no change. A friend tells me that a faulty GFI can create a partial ground causing a voltage drop and a power drain. That's well over my head and I have no idea if he's on to something or....

 

[WaynePflughaupt]

Not sure if you’re asking a general electricity question or a question about how it relates to your HT system, but voltage fluctuations are perfectly normal. It will usually swing higher or lower at different times of the day. Typically things are fine as long as voltage stays above 105v. So, no reason to hire an electrician. Unless you have him put in dedicated circuits for your system. That’s never a bad idea.

Regards,
Wayne A. Pflughaupt

 

[sholling]

Not sure if you’re asking a general electricity question or a question about how it relates to your HT system, but voltage fluctuations are perfectly normal. It will usually swing higher or lower at different times of the day. Typically things are fine as long as voltage stays above 105v. So, no reason to hire an electrician. Unless you have him put in dedicated circuits for your system. That’s never a bad idea.

Regards,
Wayne A. Pflughaupt

I'm asking because the voltage regulator in the AV rack in my bedroom kicks on fairly often and so does the voltage regulator in the AV cabinet in my family room, as well as 2 computer UPSes. Since we have several electrical engineering types here I thought I'd ask because I don't want to damage my equipment. If I fry a $3000 TV I'm just out of luck for a while. However if I'm just being paranoid I can live with boxes switching to regulated voltages.

The voltages given were 120-121 into the meter, dropping to 116 at the panel, and 110-115 inside the house. That's not an external fluctuation, that's a loss within the house itself.

 

[WaynePflughaupt]

Okay, but...

Voltage to my power outlets is 111-116v with a normal load dropping to 110-115 under a good load.

What would be a “good load?” Depending on the load, a 5v drop wouldn’t be earth shattering. Now, if you have everything in the house turned off and you’re getting a 5v drop – that I’d be concerned about.

Regards,
Wayne

 

[sholling]

Okay, but...
What would be a “good load?” Depending on the load, a 5v drop wouldn’t be earth shattering. Now, if you have everything in the house turned off and you’re getting a 5v drop – that I’d be concerned about.

Regards,
Wayne

With the edison tech monitoring the main power feed to the meter (steady at 120-121v) I checked the panel and with everything off the panel was only getting 116v. I ran inside and with nearly everything off I saw 112-115v at the wall. With a receiver, amp, 52" LCD, computer and some CF lights running just firing up the PS3 will kick on the power conditioner for a few seconds (set for 110). I know I'm not drawing a ton of power because I've never tripped a breaker.

I'm starting to think the root of the problem is the 4-5v loss in the inches between the meter and the panel is the bottleneck.

 

[WaynePflughaupt]

With the edison tech monitoring the main power feed to the meter (steady at 120-121v) I checked the panel and with everything off the panel was only getting 116v. I ran inside and with nearly everything off I saw 112-115v at the wall.

Wow. Well, between that and your high light bills, I’d say it’s time to call an electrician.

Regards,
Wayne A. Pflughaupt

 

[highfigh]

I'm starting to think you're right. I get some breathtaking electric bills yet other then my AV gear and a computer I shouldn't be drawing that much power. Every light in the house is florescent and I had the "builder" central AC replaced with with a high efficiency system. Heat, hot water and cooking are all gas. Could 10" of bad wire between the meter and the panel be losing 5V and converting a percentage of what I'm drawing to waste heat? I don't poke around on the hot side of the main so I'll have to bring in a professional to look at it. If I do I'll have a surge suppressor installed at the same time.

Just for grins I replaced the two 15A breakers that feed the wall plugs and split off the power circuits for the garage off to a new breaker of their own but no change. A friend tells me that a faulty GFI can create a partial ground causing a voltage drop and a power drain. That's well over my head and I have no idea if he's on to something or....

You mentioned the utility's side of the meter being at 121V- how were you able to measure this? If your bills are really high, call the power company and have them do an energy audit. Also, turn off the main breaker and watch the meter. If it still advances, you have a wiring problem and it needs to be repaired ASAP.

 

[sholling]

You mentioned the utility's side of the meter being at 121V- how were you able to measure this? If your bills are really high, call the power company and have them do an energy audit. Also, turn off the main breaker and watch the meter. If it still advances, you have a wiring problem and it needs to be repaired ASAP.

The power company measured it while I measured the voltage at the breaker. Turning off the breaker and watching the meter is a good idea and I'll do that tomorrow.

 

[TLS Guy]

I think you also have trouble where the main feed from the meter enters the panel. a 5 volt voltage drop at that point is excessive. Your UPS devices should not be cutting in that often at this time of year.

PM Rickster he is a good electrician.

 

[highfigh]

The power company measured it while I measured the voltage at the breaker. Turning off the breaker and watching the meter is a good idea and I'll do that tomorrow.

That might be a valid test if the voltage had been measured with the same meter at both locations, but it's possible that one isn't correct. However, since you said that you have had "breathtaking" electric bills, I would say it's possible that your meter is accurate enough.

Get one of these and use it at every receptacle-
http://www.google.com/products/catalog?q=OUtlet+tester&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&cid=5917360384558955116&ei=WAWfTO-vMIOfnQe5iqWYDQ&sa=X&oi=product_catalog_result&ct=result&resnum=1&ved=0CCIQ8wIwAA#

Buy it locally but don't spend much for it- they're all the same.

 

[westom]

I'm starting to think the root of the problem is the 4-5v loss in the inches between the meter and the panel is the bottleneck.

You don't yet know how accurate your meter is. With nothing inside the house powered on, your meter must read exactly what the AC transformer voltages is. IOW with nothing on, then your meter reading 116 volts is the same voltage that Edison Tech measured as 120.

Now power on some major appliances. Your entertainment system is near zero power. Turn on an electric oven, electric dryer, air conditioner, clothes iron, refrigerator, washing machine, etc. If a wiring fault exists, you will see voltages at some other receptacles drop. If not, then you have no problem with the meter to breaker box connection.

That GFCI tester will only report major problems. Obviously, it will not report problems that are causing single digit or ten volt drops. Anything the GFCI tester might report is already reported by your meter. But first learn how voltage numbers change between no load and maximum load.

How high are high bills? How many more kilowatts does your electric bill now say you are charged for? And how many were consumed in bills from years earlier (or by neighbors)? Kilowatts is a critical number. How that number (not dollars) changes over the months is important information.

 

[Rickster71]

Are you near the coast in California; I’m wondering about a wet salty environment?
I’d check to see if they ran Aluminum wire from the meter to your panel. There’s nothing wrong with aluminum wire; though the connections have to be made properly, and coated with an anti-oxidizer.
Without the grease like coating, they build up resistance.
Has the PoCo checked the meter for accuracy?

 

[sholling]

You don't yet know how accurate your meter is. With nothing inside the house powered on, your meter must read exactly what the AC transformer voltages is. IOW with nothing on, then your meter reading 116 volts is the same voltage that Edison Tech measured as 120.

Now power on some major appliances. Your entertainment system is near zero power. Turn on an electric oven, electric dryer, air conditioner, clothes iron, refrigerator, washing machine, etc. If a wiring fault exists, you will see voltages at some other receptacles drop. If not, then you have no problem with the meter to breaker box connection.

That GFCI tester will only report major problems. Obviously, it will not report problems that are causing single digit or ten volt drops. Anything the GFCI tester might report is already reported by your meter. But first learn how voltage numbers change between no load and maximum load.

How high are high bills? How many more kilowatts does your electric bill now say you are charged for? And how many were consumed in bills from years earlier (or by neighbors)? Kilowatts is a critical number. How that number (not dollars) changes over the months is important information.

I'll run the suggested tests. It's very possible that one of the multimeters was wrong. My multimeter and two of my UPS readouts agree on voltage but the power company guy was using his backup meter. His regular meter was missing from his truck.

My usage is pretty high but I live in a hot area (105 today) and I'm home all the time. During winter months 950-1100w, during a hot summer month it can be 1500-1900w. We're on a punitive graduated pricing system so when I say sky high that's roughly $130-330. That's sky high to me.

 

[majorloser]

It's a shame you couldn't get your hand on a thermal imaging camera. That's how you can easily find lose connections, hot legs and faulty electrical components without having to get too deep into testing. We use one at work to monitor all of our electrical switchgear. The cost has come down so much to make it well worth the cost. Can pay for itself the first time in a large industrial setting. Fluke makes some nice ones:
http://us.fluke.com/fluke/usen/products/categoryti

Here's an example of one leg running hot. Most likely a lose connection:

You might be able to find a home inspector or AC inspector that has one who could shoot your whole house. AC inspectors use them to find leaks in the walls, doors and windows. They can also shoot the power drop right on the pole or at the transformer. It's not unusual for the power company to have bad terminations.

What's really cool is to shoot the inside of your roof after a rain storm. Anywhere you see a cool spot is where a leak is developing. You can stop it before it even drips.

http://www.inspectorpaul.com/charlotte_thermal_imaging_infrared_nc_sc.html

 

[sholling]

Are you near the coast in California; I’m wondering about a wet salty environment?
I’d check to see if they ran Aluminum wire from the meter to your panel. There’s nothing wrong with aluminum wire; though the connections have to be made properly, and coated with an anti-oxidizer.
Without the grease like coating, they build up resistance.
Has the PoCo checked the meter for accuracy?

I'm well inland in the hot and dry scrublands. We get about 10-12" of rain a year and humidity gets as low as 8-10% and averages probably 30-40%.

I'll take a peek in the box tomorrow. I know the main cable from the local distribution box by the street to my meter is aluminum and I'm guessing (from memory) 5/16-3/8 diameter.

 

[majorloser]

I hate alluminum.

They banned it from use inside the home, but allow it at the entry. The largest wires in the home. Not sure if the NEC has changed to ban them all together, but they should. Copper is the only way to go.

Here in Florida with all the heat and humidity, alluminum wires eventually corrode and can eventually lead to a fire. Almost all of the older houses here with alluminum wire eventually end up having to do some major repairs.

 

[highfigh]

I hate alluminum.

They banned it from use inside the home, but allow it at the entry. The largest wires in the home. Not sure if the NEC has changed to ban them all together, but they should. Copper is the only way to go.

Here in Florida with all the heat and humidity, alluminum wires eventually corrode and can eventually lead to a fire. Almost all of the older houses here with alluminum wire eventually end up having to do some major repairs.

But copper is a lot more expensive and heavier than aluminum and for long drops from the pole, Al puts a lot less strain on the anchor, building, etc.

 

[westom]

I'll run the suggested tests. It's very possible that one of the multimeters was wrong. ...
My usage is pretty high but I live in a hot area (105 today) and I'm home all the time. During winter months 950-1100w, during a hot summer month it can be 1500-1900w.

First, if that is your energy consumption in kilowatt-hours (not watts), then your energy costs are typical. Nothing in your wiring will cause energy demands to increase hundreds of kilowatt-hours.

For example, a more likely reason for higher energy consumption could be an air conditioner that needs coolant recharging. Or (long shot) you have one of those new electronic meters that are measuring more power than you are actually consuming. Either way, wiring problems are not causing a massive energy increase. Consulting your neighbors for their kilowatt-hour numbers also provides a useful comparision.

Second, do not try to fix any of those things until first learning if a problem really exists. With no appliances drawing power, a multimeter will read utlity voltage. As major appliances power on, you should see voltages drop. How large the drop says everything about your wiring. Numbers so that others can provide useful replies.

A simpler tool is an incandescent light bulb. If the light bulb changes intensity (dim or brighten) as appliances power cycle, then you have identified a potential wiring problem or a utility transformer problem. If the incandescent lamp does not change intensity when major appliances power cycle, then you have no wiring problems. No reason to entertain all those solutions.

Your meter will provide numbers so that others can confirm what a light bulb reports. The meter is also the simplest tool to quickly locate a defect should a defect actually exist.