Eddy Current
Senior Member
Is the pilot light in some GFCI receptacles considered phantom voltage?
GFCI and Phantom Voltage
- Thread starter Eddy Current
- Start date
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jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
No.
Phantom or Ghost voltage is a false reading on a high impedance meter.
The pilot light is a real load powered by a true voltage source.
A load, power draw, and voltage potential are way two different things
Phantom or Ghost voltage is a false reading on a high impedance meter.
The pilot light is a real load powered by a true voltage source.
A load, power draw, and voltage potential are way two different things
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Eddy Current
Senior Member
If the GFCI is not being used would it save electricity to push the button and turn off the pilot light or am i crazy? Is it so minute that it wouldn't even make a difference?
ptonsparky
Tom
- Occupation
- EC - retired
To you as a customer, no difference. World wide, most likely. How much? IDK.
- Occupation
- Licensed Electrician
If you loaded the trunk of your car, the passenger seat, the back seat, the trunk, the glove box, all your pockets and any other place available with salt and took a drive down to the ocean and threw all of it in what would happen to the water?
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
130704-0819 EDT
A Leviton GFCI receptacle is an 0.9 W load when tripped, and 1.1 W when RESET.
With 8766 hours in a year, the energy used per year is 8766*1.1/1000 = 9.6 kWh. At $0.16 per kWh the cost is $1.54 per year per GFCI. The politicians should really get on this power waster, and require switches to disable GFCIs when not in use. Note: when my cell phone charger is not connected to a cellphone it is about an 0.2 W load, and the politicians want me to unplug my unused cell phone charger.
Note: an average year has very close to 365.25 days, and only needs correction every 400 years.
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A Leviton GFCI receptacle is an 0.9 W load when tripped, and 1.1 W when RESET.
With 8766 hours in a year, the energy used per year is 8766*1.1/1000 = 9.6 kWh. At $0.16 per kWh the cost is $1.54 per year per GFCI. The politicians should really get on this power waster, and require switches to disable GFCIs when not in use. Note: when my cell phone charger is not connected to a cellphone it is about an 0.2 W load, and the politicians want me to unplug my unused cell phone charger.
Note: an average year has very close to 365.25 days, and only needs correction every 400 years.
.
- Location
- Illinois
- Occupation
- retired electrician
Studies have said that phantom or vampire loads are about 6% of the total electrical use.
Really sounds high to me, but have read that figure in more than one source.
My son did an electrical engineering co-op for one of the major appliance maufacturers and one of the projects he worked on was to reduce the "standby" loads for the appliances.
Really sounds high to me, but have read that figure in more than one source.
My son did an electrical engineering co-op for one of the major appliance maufacturers and one of the projects he worked on was to reduce the "standby" loads for the appliances.
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gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
130704-1204 EDT
In standby My Sony LCD TV reads 0 W on my Kill-A-Watt EZ. This particular Kill-A-Watt reads 0.3 W with a 40,000 ohm load at 120 V. Calculated power is 0.36 W. Reads 0 W with 80,000 ohm load. Thus, Sony is less than 0.3 W. Yet the Sony can be turned on with the IR remote. Different Kill-A-Watt EZ units have varying capability at these very low power levels.
With good engineering and some cost increment quite low standby power can be achieved. Back in the early 80s IBM added a clock chip made by Motorola to the IBM PC with battery backup. A fairly good size battery with no AC power would last about 3 months. Yet at this time Dallas Semiconductor was making clock chips with an included very small battery that could run for 10 years with no external power. The decision to use the Motorola chip was stupid and caused millions of customers a lot of time and cost relative to battery replacement. The cost benefit was not in the customer's favor.
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In standby My Sony LCD TV reads 0 W on my Kill-A-Watt EZ. This particular Kill-A-Watt reads 0.3 W with a 40,000 ohm load at 120 V. Calculated power is 0.36 W. Reads 0 W with 80,000 ohm load. Thus, Sony is less than 0.3 W. Yet the Sony can be turned on with the IR remote. Different Kill-A-Watt EZ units have varying capability at these very low power levels.
With good engineering and some cost increment quite low standby power can be achieved. Back in the early 80s IBM added a clock chip made by Motorola to the IBM PC with battery backup. A fairly good size battery with no AC power would last about 3 months. Yet at this time Dallas Semiconductor was making clock chips with an included very small battery that could run for 10 years with no external power. The decision to use the Motorola chip was stupid and caused millions of customers a lot of time and cost relative to battery replacement. The cost benefit was not in the customer's favor.
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kwired
Electron manager
- Location
- NE Nebraska
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
130704-1853 EDT
kwired:
The ultimate cost to the customer far outweighed the small manufacturing cost increase.
What I heard was that Dallas was too small of a company. Sort of like the problem with HP and its calculator key tops. A small company developed and made the original calculator key tops for HP calculators for a long time. Sometime late in the HP calculator life when HP was not family run any more, and business people were running it, then those in charge decided that the keytop supplier was too small. By this time HP was not the company it originally was, it had become a marketing company. HP changed to some other supplier, a bigger company, but the new company's product was not as good as the original supplier.
That HP became a marketing company rather than a technical company is probably the reason the good HP calculator line was dropped.
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kwired:
The ultimate cost to the customer far outweighed the small manufacturing cost increase.
What I heard was that Dallas was too small of a company. Sort of like the problem with HP and its calculator key tops. A small company developed and made the original calculator key tops for HP calculators for a long time. Sometime late in the HP calculator life when HP was not family run any more, and business people were running it, then those in charge decided that the keytop supplier was too small. By this time HP was not the company it originally was, it had become a marketing company. HP changed to some other supplier, a bigger company, but the new company's product was not as good as the original supplier.
That HP became a marketing company rather than a technical company is probably the reason the good HP calculator line was dropped.
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kwired
Electron manager
- Location
- NE Nebraska
I understand that, but some still purchase things based on retail price alone and don't look at the overall cost of owning and operating an item. This was even more likely at that time than it would be today, IIRC back around that time cheap usually sold well, quality was not always considered.
Rick Christopherson
Senior Member
It is not a false reading on a high impedance meter. That is the correct reading. A low impedance meter masks this reading so you don't see it. It is actually the low impedance meter that is displaying the false reading.
kwired
Electron manager
- Location
- NE Nebraska
Neither is a false reading. They are different readings because each meter type presents different conditions that effect the reading. The user must understand why in order to use the meter more successfully.
Rick Christopherson
Senior Member
Actually the second (analog) reading is a false reading. A basic scientific principle is that your measurement of a system should not alter that system. That is why meters (all of them) have relatively high impedance compared to what they are supposed to measure. The reason why your analog meter does not show this voltage is because it is altering the system it is measuring.
It is not correct to say that an analog meter is showing you a correct reading when it shunts the voltage. You may not like the true reading, and it may confuse you, but it is nevertheless the more correct of the two readings.
Stating that a "phantom" voltage is a "false" voltage is the most egregious of the errors. It is in fact the real voltage.
It is not correct to say that an analog meter is showing you a correct reading when it shunts the voltage. You may not like the true reading, and it may confuse you, but it is nevertheless the more correct of the two readings.
Stating that a "phantom" voltage is a "false" voltage is the most egregious of the errors. It is in fact the real voltage.
kwired
Electron manager
- Location
- NE Nebraska
When testing with a high impedance meter it is also altering the circuit, just not as much.
We have similar type of thing when using a regular multimeter to measure resistance and compare it to using a high test voltage with a megger to measure resistance. The the testing device itself introduces different characteristics into the circuit being tested so we are not really testing for the same thing in each case.
We have similar type of thing when using a regular multimeter to measure resistance and compare it to using a high test voltage with a megger to measure resistance. The the testing device itself introduces different characteristics into the circuit being tested so we are not really testing for the same thing in each case.
mivey
Senior Member
Rick,
It is not true that a measurement system will not alter the system. While that is true for some measurements, many times we purposefully alter the system by adding things like filters to find the information we seek. Think about the open-circuit and short-circuit system changes we make to measure Thevenin and Norton circuit parameters.
You have to be clear on what voltage you are trying to read. In most cases we want the low impedance voltage source, not the high impedance voltage source that gives us the "phantom" voltage.
Since the very high impedance meter can't distinguish between the two, we use a lower impedance meter like a filter to look for the lower impedance voltage source. In this case, the analog meter gave us the true reading since our objective was to measure the low impedance voltage source.
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