Do GFCI outlets waste power?

[nehog]

Depends on the efficientcy rating of the transformer and its impedance rating. Im sure they're not the most efficient, so i bet they waste a good amount!

The switching mode supplies are very efficient.

Same as I mentioned on the GFCI, leave it plugged in a while and see how warm it is. If you can tell it's warm, it's drawing (too much) current. If it is hot or even very warm I would not recommend leaving it unattended.

 

[madosta]

ddawg16 FTW. Exactly what I was hoping someone would do so I don't have to unbox all my stuff.

 

[Bill1234]

I stumbled across this thread. I know it is an old thread, but it got me thinking about my GFIs. I checked the one by the main breaker panel and was reading aprox. 150mA with an the meter in-line. That works out to 18 watts @ 120V. I thought that was quite a bit since there are seven GFIs in my house that I count. That would be like having a 100 watt bulb on all of the time. Then I got to thinking about phantom reading due to the impedance in the GFI.

Today I turned off all the breakers except the ones feeding the GFI circuits. I then went to the service entrance meter (the one the power company reads) and watched the spinning disk (you know the one that looks like it is going to fly out of the meter when your AC is running). It was not moving at all. This means no power consumption by the GFIs. If there actually was 150mA consumption by just that one GFI then that would mean 18 watt-hours consumption over a 1 hour period just for one power stealing GFI. That means the disk on the entrance meter would have revolved 4.6 times in one hour (1 revolution equals 7.2 watt hours for my meter). I left only the GFI circuits energized for over two hours and absolutely no movement of the disk in the service entrance power meter even though I was still reading about 150mA (or 16 watts) at just that one GFI. This phantom current reading happens when trying to read the current in a high inductance or high capacitance circuit with a meter that is not designed for such readings. The amperage read with most DVM's (I was using a Fluke 83).

If you are concerned about you GFI outlets then do the same experiment. If you turn off all of the circuits except the one powering the GFI and have everything else unplugged from the circuit and are see the spinning disk moving at your power companies service meter try tripping the GFI using the test button. If the power companies meter then stops this means you probably have a bad GFI outlet or still have something plugged into the circuit drawing power.

I powered on one at a time my circuits which supplied my "always on" devices (Cordless phone-answering machine, alarm clock, door bell, smoke detectors, range (the clock), microwave, radon vent fan, furnace control circuit, landscape light power supply (daylight so lights were off) and my two garage door openers. The total consumption was aprox. 62 watts per hour. The spinning disk was revolving once every 7 minutes which equals about 8.5 revolutions per hour or about 62 watts/hour. The biggest surprise when powering each circuit on was the consumption of my two garage door openers in stand-by mode (overhead lights were off). They are consuming a combined 25 watts per hour which is a large portion of my "always on" appliances. That is significant as it equals about $30 a year just for the door openers to be standing by. That is a circuit I am now considering adding switches to to cut the power when they are not in use, especially to the one which is never used during the winter.

 

[Charles (in GA)]

As I was looking at this thread, I was thinking "Oh God, not another thread resurrection" but this is one of those rare instances where It is a good thing. I'm going to start paying attention to my vampire loads and how much they are. As someone noted, waste is waste, and if any noticeable reduction can be made its probably worth it.

I also suspect that the GFCI makers have got on the bandwagon and have been making more efficient devices which may (or may not) be worth installing, we'll see.

Now, excuse me, I gotta get back out to the shop and continue working on the cabinet I'm building to mount on the back of the house to shelter the EVSE for plugging the electric car into. The POCO has offered me a FLAT RATE for the next year and I figure I can make $150 or more by charging the car off the house meter, rather than the shop meter.

Charles

 

[Kevin C]

Based on specs for GFCI and tests on the web, a typical current draw for a GFCI is 4 to 8 ma.

7 ma * 120V = 840 mW or 0.84W or .000816 KW If you're paying 7 cents per KWH and your GFCI is on 8760 hours per year, then: 0.00084 * 8760 =7.36 KW hours of energy per year.

7.36*0.07 f/kwh= $0.52 per year, per GFCI.

As some pointed out, the GFCI probably has a pretty high power factor, so a direct current reading won't convert to actual power draw, you need to compensate for the phase angle of the power draw relative to the voltage to get the actual wattage.

Teken did a good job with his measurements and demonstrated that the OP readings were off by about a factor of ten from typical.

All we can conclude is that either the measurements were flawed or that the OP has a very strange set of GFCI's.

For the rest of us, its about $0.52 a year per GFCI @ 7 cents per kWh.

 

[Charles (in GA)]

For the rest of us, its about $0.52 a year per GFCI @ 7 cents per kWh.

Seven cents per kwh is CHEAP. I suspect most of the country pays a lot more. GA Power doesn't tell you how much a kwh costs, so I take the bill (which includes taxes and fixed costs) and divide by the kwh consumed gives me $0.148 per kwh on the shop and $0.146 for the house.

I suspect this is a more common rate. Guess I'll have to give up a soft drink or two this year.

 

[Kevin C]

Seven cents per kwh is CHEAP. I suspect most of the country pays a lot more. GA Power doesn't tell you how much a kwh costs, so I take the bill (which includes taxes and fixed costs) and divide by the kwh consumed gives me $0.148 per kwh on the shop and $0.146 for the house.

I suspect this is a more common rate. Guess I'll have to give up a soft drink or two this year.

Good point... Using your method, I get $0.112 per kWh or $0.82 per GFCI per year.

Thanks,

Kevin

 

[pennsylvaniaboy]

Maybe it is just me, but why in the world do you need a gfci on every single outlet? Put them on units exposed to water and be done.

 

[ddawg16]

Maybe it is just me, but why in the world do you need a gfci on every single outlet? Put them on units exposed to water and be done.

Yea, it's you.

Per the NEC, they are required in bathrooms, kitchen counter tops...your garage....outside.

 

[Charles (in GA)]

Maybe it is just me, but why in the world do you need a gfci on every single outlet? Put them on units exposed to water and be done.

Well, you don't really. The code requires GFCI PROTECTION in kitchens, bathrooms, within 6 ft of sinks, on grade level of accessory buildings, outside receptacles, and a few other places. The protection can consist of of one GFCI circuit breaker protecting the bathroom circuits, outdoor circuits, etc. It could consist of one breaker protecting a whole string of receptacles in a shop.

Its largely due to the lack of planning by electricians and people stringing wires, and the cost of GFCI breakers, that people install the GFCI receptacles instead.

 

[wyliesdiesels]

Seven cents per kwh is CHEAP. I suspect most of the country pays a lot more. GA Power doesn't tell you how much a kwh costs, so I take the bill (which includes taxes and fixed costs) and divide by the kwh consumed gives me $0.148 per kwh on the shop and $0.146 for the house.

I suspect this is a more common rate. Guess I'll have to give up a soft drink or two this year.

are u sure about that?

PoCos are REQUIRED to publish their rates.

And i found yours in less than 2 seconds with google by seqrching for "ga power tariffs"

http://www.georgiapower.com/pricing/residential/residential-tariffs.cshtml

http://www.georgiapower.com/pricing/files/rates-and-schedules/residential-rates/2.10_R-21.pdf

Assuming u are on the R21 standard service schedule, u pay(5.5747 cents less than a third of what i do (16.49 cents and 18.08 cents in the summer).

And unless your taxes and fees are high, i dont see how u came up with .148 cents looking at the above PDF...

This is what we pay in the scorching central valley of CA:

http://www.mid.org/tariffs/rates/D_RESIDENTIAL.pdf

Thats a BIG OOUUUCCHH!

 

[Charles (in GA)]

Last time I looked, two or three years ago, none of that was to be found on their website. Tariffs are not confusing, its all the **** added onto the bill. I do the simple math, as that is the real world, that is what I pay for my power.

House, Jun 10 to July 10. I used 981 kWh.
Current service, which is a fixed monthly fee plus the per kWh cost was $116.70.
Environmental compliance cost was $8.43
Nuclear construction cost recovery was $7.28
Municipal franchise fee was $1.44
Sales tax was $9.37
The total was $143.22

$143.22 divided by the 981 kWh is $0.14599 (this is my real world cost for power)

The shop, separate meter, same residential rate, is slightly higher per kWh because the fixed monthly fee is a larger portion of the Current service.

Jun 9 to Jul 10 I used 411 kWh. A good portion (close to half) was for charging a Nissan LEAF.
Current service was $49.59
Environmental compliance cost was $3.61
Nuclear construction recovery cost was $3.11
Municipal franchise fee was $0.61
Sales tax was $3.99
Total bill was 60.91

$60.91 divided by 411 kWh is $0.14819

The LEAF drove the shop bill from $30 a month to $60, so it is costing about $30 a month to "fuel" it for 1000 miles (I did get one free fast charge at the dealer during this time). This is about Three cents per mile, as opposed to gas for my 32 mpg Vibe being over seven cents per mile.

 

[wyliesdiesels]

Yeah those fees are ridiculous! It tripled your overall rate!

Especially the nuclear one...why should rate payers have to pay for the electric companies choice of power generation! What happens when the plant fails because of design flaws? Theyre gonna stick it to the rate payers just like what happend with San Onofree!

 

[pennsylvaniaboy]

Yea, it's you.

Per the NEC, they are required in bathrooms, kitchen counter tops...your garage....outside.

Yes, Thats is where most people see them. But i know many many garages that do not have every single outlet as a gfci

Well, you don't really. The code requires GFCI PROTECTION in kitchens, bathrooms, within 6 ft of sinks, on grade level of accessory buildings, outside receptacles, and a few other places. The protection can consist of of one GFCI circuit breaker protecting the bathroom circuits, outdoor circuits, etc. It could consist of one breaker protecting a whole string of receptacles in a shop.

Its largely due to the lack of planning by electricians and people stringing wires, and the cost of GFCI breakers, that people install the GFCI receptacles instead.

I still think a gfci breaker would be far better than every outlet.

 

[jesseritz]

30 Watts is .03 kW x .15 (kWh rate in SE PA) x 24 hrs x 365 days = almost $40.

 

[reader2580]

My parent's house was built in 1979 and they used one GFI for the entire house. They have two bathrooms, outside receptacles, and garage receptacles on a single circuit. Wire and labor was cheaper than GFI receptacles back then. I don't believe kitchens required GFI at the time.

2014 NEC code would not allow one GFI for an entire house as the garage, kitchen, bathroom, and laundry each need their own circuits with GFI protection.

I've never tried to measure GFI power consumption. I leave my laptop on 24x7 which certainly takes more power than GFIs. My electricity bill averages about $60 a month.

 

[Ericpwp]

You can run a sub-panel fed with a single double pole gfci breaker to protect multiple circuits.

I protected most of the house this way after a guy in my town was electrocuted vacuuming water in his basement.

I also have a detached garage protected this way.

 

[carlh6902]

So being a good boy I was adding GFCIs to protect each outlet in my shop. I'm a bit of an energy conservation nerd and while trying to reduce my standby load at my main panel I noticed a pretty hefty vampire load on the shop circuit that feeds the subpanel. WTF? Everything is off in the shop. So I pulled off the shop subpanel cover and clamped my ammeter on each circuit and with the Leviton GFCI "on" I was burning 0.06 amps or 7 watts. Pop the test button and amperage read zero. Repeat for each outlet circuit.

Are my expensive GFCIs broken? These do have the ultra tiny LED light on them to indicate protection. I have 9 watt LED flood lights in my house that put out 650 lumens. So wasting 7 watts for each GFCI chaps my ****.

What gives?

Those things use very little power. If they were really dissipating 7w each, they would be getting noticeably hot to the touch.

Carl

 

[Dick in Wisconsin]

The biggest surprise when powering each circuit on was the consumption of my two garage door openers in stand-by mode (overhead lights were off). They are consuming a combined 25 watts per hour which is a large portion of my "always on" appliances. That is significant as it equals about $30 a year just for the door openers to be standing by. That is a circuit I am now considering adding switches to to cut the power when they are not in use, especially to the one which is never used during the winter.

I wonder what kind of garage door openers Bill has.

Those things use very little power. If they were really dissipating 7w each, they would be getting noticeably hot to the touch.

Carl

I agree with Carl.

What is the final conclusion then? GFCI don't use much if any power when they are just "sitting there"? Granted the tiny LED that is always on probably uses a tiny fraction of a watt.