[morrison49th]

Hello all,

I moved into a house in the USA (WA) later last year. I lived in an apartment before (think it was a 90s build). In the apartment whenever we plugged and turned on the vacuum in the lights would go a little bit dimmer and remain dimmer until it was turned off. When I moved into our house (build mid 70s), great seattle area, the same thing happens. If I vacuum lights go dim temporarily. When the heating turn on (presumably heat pump and electric furnance), the lights will dip in brightness then return to full brightness. I kind of thought this is just American domestic lighting, but I'm willing to bet that more modern constructions don't suffer from this. So, what is causing this? What's likely to be causing this (I fugured it's a large current draw causing a voltage sag)? Is it my old breaker panel? Bad wiring? Shared netural/ground bar?

Thanks

 

[AllanJ]

You need to measure the voltage the vacuum cleaner is actually getting. Usually the simplest way is to put the voltmeter probes in the other half of the receptacle the vacuum is plugged into.

A drop of less than three volts can be ignored.

The wiring from the receptacle you are using back to the breaker panel may daisy chain through other receptacles. A loose connection at any of these locations can cause a somewhat greater voltage sag and this is also hazardous because loose connections also generate heat, sometimes enough heat to start a fire even though not using enough power to trip a breaker.

A loose connection upstream of the breaker panel cannot be ruled out. Someone with a lot of electrical experience should measure the voltage, hot to neutral on both legs, at the panel when the vacuum is turned on and off.

 

[joecaption]

Could be many things. (but not the shared ground and netural)
What size is the main breaker to start with?
Aluminum or copper wire?
What brand is the panel?

 

[morrison49th]

You need to measure the voltage the vacuum cleaner is actually getting. Usually the simplest way is to put the voltmeter probes in the other half of the receptacle the vacuum is plugged into.

A drop of less than three volts can be ignored.

The wiring from the receptacle you are using back to the breaker panel may daisy chain through other receptacles. A loose connection at any of these locations can cause a somewhat greater voltage sag and this is also hazardous because loose connections also generate heat, sometimes enough heat to start a fire even though not using enough power to trip a breaker.

A loose connection upstream of the breaker panel cannot be ruled out. Someone with a lot of electrical experience should measure the voltage, hot to neutral on both legs, at the panel when the vacuum is turned on and off.

Upstream meaning outside of the house (towards the electrical substation).

Understand about the daisy chaining, and I know for a fact some are.

Anyway I stuck the vacuum in the upper socket and multimeter leads in the lower. Read ~122.4V before turning vacuum on. As luck would have it the main heating kicked in (heat pump outside house, electrical furnance in crawl space - complete seperate breaker), and the voltage dropped to 115.9V (6.5V drop). When I turned on the vacuum, the voltage dropped to 110.9V (further 5V drop). I tested this with the outlet connected to my kitchen lights. These lights only seem to briefly get brighter when the vacuum is turned off (rather than go obvoiusly dim when it's turned on). Any thoughts on this.

Could be many things. (but not the shared ground and netural)
What size is the main breaker to start with?
Aluminum or copper wire?
What brand is the panel?

Breaker pannel:
http://snag.gy/BZK0f.jpg

Size: Says 200 Amp on the big switch

Manufacturer - Siemens (at least the breakers are Siemens style).

Big fat wires coming in - aluminium

 

[MrElectricianTV]

Hello all,

I moved into a house in the USA (WA) later last year. I lived in an apartment before (think it was a 90s build). In the apartment whenever we plugged and turned on the vacuum in the lights would go a little bit dimmer and remain dimmer until it was turned off. When I moved into our house (build mid 70s), great seattle area, the same thing happens. If I vacuum lights go dim temporarily. When the heating turn on (presumably heat pump and electric furnance), the lights will dip in brightness then return to full brightness. I kind of thought this is just American domestic lighting, but I'm willing to bet that more modern constructions don't suffer from this. So, what is causing this? What's likely to be causing this (I fugured it's a large current draw causing a voltage sag)? Is it my old breaker panel? Bad wiring? Shared netural/ground bar?

Thanks

As others have mentioned it could be a combination of several things. Poor connections, excessive load, too small of an electrical service, and even an undersized power company transformer could all contribute to your problem. Do your neighbors have similar issues?

One thing I would suggest is to contact your power company and tell them your problem. Have them check their lines.

Get an electrician to check all of your outlet and switch connections and also the terminations inside of the electrical panel and the meter. The connections at the weatherhead should be checked also, but the power company may do that.

 

[morrison49th]

I think I should correct something. The lights don't seem to stay dim here (like in my old apartment), rather they just go bright when there is a current surge (heater or vacuum turns on/off). I just did another test where I plugged the vacuum in downstairs then on a seperate breaker circuit measured he voltage drop on an outlet (1.5V).

As others have mentioned it could be a combination of several things. Poor connections, excessive load, too small of an electrical service, and even an undersized power company transformer could all contribute to your problem. Do your neighbors have similar issues?

One thing I would suggest is to contact your power company and tell them your problem. Have them check their lines.

Get an electrician to check all of your outlet and switch connections and also the terminations inside of the electrical panel and the meter. The connections at the weatherhead should be checked also, but the power company may do that.

Electricians cost a lot of money, especially eastside of Seattle. Angies list is a bit hit and miss. Of course I want to stay safe and have insurance pay out if the house did catch on fire, but I don't want to not be frugal. I'd be super happy if someone could recommend an affordable reputable electrician in the Bellevue/Redmond area.

I think I will take you up on the weather head after a bit more investigating as that will hopefully be free (though I don't want to waste the power company's time and money)

Thanks

 

[psgama]

Quickest test to see where the problem is occurring,

Bring your vacuum cleaner downstairs. You should have a receptacle at your panel. Plug it in there and turn it on, if your lights dim downstairs, upstairs, anywhere, you may have a loose connection or a loading issue with your panel somewhere from the utility transformer to your service disconnect (Main Breaker)

It could be the connections to your main breaker, the connections in your meter base, the utility connection at your weather head or the utilities transformer under too heavy a load, although I doubt that, as your voltage seems to be good without any load.

If your lights aren't dimming from downstairs attached right near to the panel, then you simply have voltage drop on the circuit you are using to vaccum, and the lights are most likely ran on the same circuit as the receptacles (Newer houses won't have this issue now, as lighting will be separated from receptacle circuits due to AFCI's having to be installed on most 15 - 20amp receptacles.)

Good luck

 

[throrope]

Since it is a new to you house, I suggest you have every breaker cycled a couple times and don't be surprised if one or two fail during test. Get all terminations in the breaker box checked for tightness. Inspect all outlets for damage and overall condition. Have every one that looks worn or cracked replaced while there. Have all exposed wiring walked down and correct any creative installations. Outlets and breakers are cheap and compared to potential consequences, insignificant.

Our house built in '97 will dim lights when a big load is applied on a general circuit.

Beyond the above, I suggest not fixing what isn't broke.

 

[morrison49th]

Quickest test to see where the problem is occurring,

Bring your vacuum cleaner downstairs. You should have a receptacle at your panel. Plug it in there and turn it on, if your lights dim downstairs, upstairs, anywhere, you may have a loose connection or a loading issue with your panel somewhere from the utility transformer to your service disconnect (Main Breaker)

It could be the connections to your main breaker, the connections in your meter base, the utility connection at your weather head or the utilities transformer under too heavy a load, although I doubt that, as your voltage seems to be good without any load.

If your lights aren't dimming from downstairs attached right near to the panel, then you simply have voltage drop on the circuit you are using to vaccum, and the lights are most likely ran on the same circuit as the receptacles (Newer houses won't have this issue now, as lighting will be separated from receptacle circuits due to AFCI's having to be installed on most 15 - 20amp receptacles.)

Good luck

The breaker is in the porch, and there are a couple of sockets, but about 10ft away. I can't see any socket immediately next to the panel. Are these sockets what I should be using? Regardless of the vacuum, when the heat pumps turn on (has it's own breaker circuit) my lights upstairs (on another breaker circuit) momentarily dip in brightness.

Since it is a new to you house, I suggest you have every breaker cycled a couple times and don't be surprised if one or two fail during test. Get all terminations in the breaker box checked for tightness. Inspect all outlets for damage and overall condition. Have every one that looks worn or cracked replaced while there. Have all exposed wiring walked down and correct any creative installations. Outlets and breakers are cheap and compared to potential consequences, insignificant.

Our house built in '97 will dim lights when a big load is applied on a general circuit.

Beyond the above, I suggest not fixing what isn't broke.

What do you mean by cycled? How do I cycle a breaker. Turn it off and on again?

I should have been more clear - the lights don't seem to stay dim in my current house, they just momentarily go dim/brighter/flicker. Especially when the heat pump turns on. I can tell the heat pump has just turned on or off because of this. In my old apartment, plugging the vacuum in would cause the lights to stay dim until the vacuum was unplugged. I can't replicate this latter behavior in my new house.

 

[bernie963]

When the lights dim, do any other lights get brighter at the same time?

bernie

 

[AllanJ]

Do some lights elsewhere in the house also dim noticeably when the heat pump comes on and/or you turn on the vacuum cleaner as plugged into the first receptacle you were using?

Incandescent lights show off dimming due to low voltage very readily.

You want to repeat the test using different receptacles, also with the voltmeter probes inserted into a different receptacle from where the vacuum is plugged in.

Make several tests. You want to measure the voltage at a receptacle connected to a different circuit on the same side of the 120/240 volt service as one of the troublesome receptacles/circuit powering the vacuum cleaner is on and and also at a receptacle on the opposite side of the service.

 

[mm11]

Voltage and current are inversely proportional, so when the current draw goes up, the voltage will drop. Any installation will have this occur, modern or not. The lights will be the dimmest at motor start-up (ie the heat pump) bc the amperage is the highest at that point. The breaker panel and common connections on the neutral bar have nothing to do with your problem.

 

[AlexPascual]

You may need a new layout of your wiring and have a professional check on it.

Regards,
Alex

 

[dmxtothemax]

Do the lights just go dimer ?
Cause at one stage you said
That they go brighter ?
If so this means a poor neutral.

 

[user_12345a]

It's normal, nothing to worry about.

When drawing 12-13+ amps on a 15 amp circuit, a bit of voltage drop is to be expected.

To not experience this problem you would have to have 20 amp circuits or a dedicated circuit for the large load.

Window air conditioners, dishwashers and dehumidifiers are intended to be used on dedicated circuits, says so right on them. With a temporary load like a vacuum cleaner you don't have to worry.

 

[morrison49th]

It's normal, nothing to worry about.

When drawing 12-13+ amps on a 15 amp circuit, a bit of voltage drop is to be expected.

To not experience this problem you would have to have 20 amp circuits or a dedicated circuit for the large load.

Window air conditioners, dishwashers and dehumidifiers are intended to be used on dedicated circuits, says so right on them. With a temporary load like a vacuum cleaner you don't have to worry.

The electric heating + heat pump are on their own circuit (50Amp breaker), yet when they come on it is noticeable anywhere in the house as the lights flicker/dim/dip.

 

[dmxtothemax]

This just means that the choke point is upstream of your panel !
Or it could just be a local grid lacking power reserve.
If its minor poco probably dont want to know
If it is major they may help.