How much power does a 120v 15A lighted switch use anyway?

[keith]

Actually, Arizona is well on the way to sending you their illegals.

[bud--]

If the switch is lighted when off, the neon lamp (and series resistor) are connected across the switch. The small current through the neon lamp flows through the load on the switch. For a 3-way switch, the lamp is connected across the travelers.

For a switch that is lighted (neon) when the switch is on, the switch probably has a neutral connection. There is a resistor from each side of the switch to the neon lamp, with the other side the lamp connected to the neutral.

LEDs could operate essentially the same, probably with an extra diode.

[David Nebenzahl]

On 5/19/2010 5:58 AM keith spake thus:

Fine. We'll happily accept them here.

[keith]

That's good, because you're getting them in any case.

[Ohioguy]

I noticed something funny about the neon light on my Dad's basement light switch. When I put my finger anywhere even NEAR the tip of the switch, the neon light appears to *JUMP* away from the end back towards the base of the switch. I assume there is something of a charge on my hand, and that is causing the neon gas 'plasma' or whatever you call it to move away? I never really investigated this, but found it very interesting.

[Don Klipstein]

Some sort of spec sheet for several neon lamps, including NE-2H, by CML Technologies (formerly Chicago Miniature Lamps):

Design current of NE-2H is 1.9 milliamps. Multiply that by 120V and the result is .23 watt.

In Philadelphia and nearby suburbs in Pennsylvania, that currently amounts to 28-29 or so cents per year, likely to go up at least 10% in January 2011, assuming 24 hour per day operation. (USA national average would be more like 22 cents now.)

This does sound small. However, I would rather consider how much that adds up to over the life of the neon lamp, knock it down slightly due to paying-later while investments likely have rate-of-return exceeding inflation in electricity cost, and consider it to be part of the switch. Would you still buy the switch at that rate?

[Don Klipstein]

In the unlikekly event an NE-2H lamp conks out and stops conducting after 25,000 hours at its design current of 1.9 milliamps, this amounts to

5.7 KWH for the NE-2H and its dropping resistor in 120V use. That is equal to 1 horsepower for about 7.5 hours - I would call that at least an order of magnitude more than reading and responding to this whole thread so far.

The electricity consumed by the neon lamp and its dropping resistor over the life of the neon lamp may cost under a dollar, may cost a couple to a few dollars, depending on your electricity rates, actual life of the neon lamp, and inflation of electricity cost. (Is that how much more you are willing to pay on top of up-front cost for having a light in the switch? As long as you are aware and willing to pay it...)

[Rod Speed]

Most likely it isnt connected properly and thats not a problem because the very low current gets thru the small capacitace fine.

[Don Klipstein]

Make that .04 watts, or .04 watt-hours per hour.

I have a lot of experience with a lighted switch at my "day job", and it is obvious to me that the neon lamp there is a "high intensity" type, probably C2A (NE-2H) or A1C ("mini NE2H").

says design current for NE-2H is 1.9 milliamps. Multiply by 120V, that means .228 watt. Since neon lamps don't conduct at less than 50-60V, I seem to think that average voltage used to push electrons through from 120 VAC is closer to 130V. That would mean closer to .25 watt.

35 cents per KWH does sound to me high. I thought Philadelphia was bad at around 14-15 cents per KWH. Chicago and NYC are close to Philadelphia in electricity cost as of last time I checked.

Meanwhile, I would balance lighted switches against another slice or two of pizza per year or a few more newspapers per year.

[Don Klipstein]

1/100 of 98 is .98. That would mean KWH per year is 2.2 times .98, which is 2.156.

[Don Klipstein]

I seem to think that if such a "p!$$ing contest" develops along with ability to ship out illegal aliens, I would think that Arizona would send them back to California, Freight Collect. Maybe along with some of their own - especially if expelling illegal aliens from a state is legally easier of not forcing them to cross or dragging them across an international border.

If California gains competence and allowance at state level of government expelling illegal aliens, it appears to me that CA would do better to send them back outside USA as a whole. If not, I seem to think that CA is not in really good shape to tick off AZ.

[Don Klipstein]

Hide quoted text -

Although I agree with your point, I would like to nit-pick that the highest common voltage for a neon sign transformer is 15 KV and most are

12KV or less, and less still when loaded down by the neon sign.

[Don Klipstein]

It is common for neon lamps to be operated with the cathode/negative glow not completely covering an electrode. In any given glow discharge lamp, this glow layer has some sort of natural current density in mA per square centimeter. If the current is low enough to incompletely cover the electrodes at that current density "rate", then the electrodes are incompletely covered by glow.

And, it is easy to cause the glow to move around. In some neon lamps operated with glow incompletely covering their eectrodes, the cathode/negative glow layer even jumps around on its own. The best example of this is "flicker flame" neon lamps.

With AC, some trace of current can flow through insulators (such as the glass bulb) due to "capacitive coupling". Each electrode has to re-fire

60 times per second with usual AC in North America (50 times per second in Europe). It sounds to me plausible for touching some neon lamps to cause their glow pattern to shift.

[Don Klipstein]

Where do you get 1 megohm being typical? I have heard of and seen mostly anywhere from 220K to 100K for NE-2 (a "standard intensity" neon lamp), and both heard of and seen 33K and sometimes seen 22K for NE-2H.

Here is some sort of spec sheet for common neon lamps, by CML Technologies, formerly Chicago Miniature Lamp Works:

Design current of NE-2H is 1.9 milliamps.

They do say A1C design current is 1.2 milliamps, but I have seen those usually getting more. They do say that design current of NE-2 is .6 milliamp.

[Mark]

Don.. ok point taken...thanks :-) Mark

[Bill]

Well it is no problem if there is just *one* and it is only on for one hour. But there are hundreds of these little lights around a home and they are on

24 hours a day 365 days a year...

As with everything else when being frugal, things add up! Learn to add.

These little power on lights are in everything these days. Try to find a power strip without any lights in it. GFCI outlets have little lights in them now. Everything has little lights.

I know electronics and electrical wiring, so I was able to disconnect all of these lights around my home (the green light in a GFCI was the straw - I said Enough!). With the GFCI's, I rewired my house so these outlets are now on 20 amp switches. They are off when not in use.

A good example are outside outlets which are GFCI. Maybe used once or twice a year in my case, but the GFCI for that is always on and using a little electricity.

My electric bill went down $2.50 a month after doing this. (GFCI's also always use electricity even if they don't have any lights.)

That is a $30 a year savings. I need that money a lot more than my electric company does.

My neighbors on the other hand (who can't add), buy things everyday which cost $1 or $2. They say it is just $1. And they do this several times a day. Buy soda pop, coffee at the stand (it is just $2.50), etc.

Then by the end of the month, they are a couple of hundred dollars short and don't have enough for their bills.

Learn to add. Little things add up...

Note: I don't suggest that people go out an hire an electrician to modify their existing wiring, that would be silly. I can do these things for almost nothing, so that is a different situation. But if you are rewiring your kitchen for example, place a couple of extra switches next to the light switch - have those switches turn off the counter top outlets. This will remove power to the GFCI's and to parasitic loads (like appliances which always use electricity). Just flip several switches and everything is off in the kitchen!

On parasitic loads... Leaking Electricity: Individual Field Measurement of Consumer Electronics - Lawrence Berkeley National Laboratory

[Gary H]

It's one of those things on the end of a power cord, that's bigger than a plug. Makes it look like some sort of fungus is growing on the wall. These are usually power supplies, but can be other things like remote controls and GFCI adapters.

[Mark Lloyd]

That's a big difference. It's about 8¢ here in east Texas (figuring from actual electric bills, NOT company ads).

[snip]

[terry]

Maybe OK in principle but ............ Problem is that based on $2,50 per month ($30.00 per year), if indeed it is that much? That just over

8 cents per-day is inconsequential in the overall cost of operating a North American home. (Less than 1% of energy bill). Eight cents per day is here (NE Canada) about 8/10ths of 1000 watt hours during one day, or the equivalent of leaving one 34 watt fluorescent tube light fixture on all the time!. Since we have a 9 'LED strip above our sink that uses ONE watt (total), which we leave on all the time, it's hard to perceive 'All the little indicator lights' adding up to anything significant!' Also recall that after WWII, in the UK, neon 'night lights' became available and my grandfather saying, with some delight, that he turned off everything in the house except the night light and 'The meter didn't even move'! As posted here previously, mains voltage neons use a milliamp or two, at 120 or 240 volts, LEDs probably less! And since all/most electrical energy entering a home ends up as heat within the house envelope anyway .................. !

[Don Klipstein]

1% here, a fraction of a percent there and other places, half a percent in a couple more, another % in each of a couple other places... That often adds up to something significant.

LEDs usually take more. Few get less than 2 mA, and 10 mA is typical. Keep in mind that most indcator LEDs even now have chip chemistries that were available in the mid to late 1970's. That is done ecause they cost less than more efficient more modern ones. With an average supply voltage that LED power comes from likely being around 5 volts in consumer products other than power strips, along with losses in the power supply, I would expect typical power consumption by and associated with each LED glowing in the house to be ~.07 watt. What if there's a lot of those?

However, I would worry more about wallwarts being plugged in all the time and computers, monitors, TVs etc. drawing a few watts each when they are plugged in but "off", and 4-7W incandescent nightlights that can be replaced by 1/3-watt to 1-watt LED ones.

Which in most places costs more per BTU than natural gas, fuel oil and heat pumps do. And when it's not heating season, the electricity cost does not offset anything. And when it's air conditioning season, the cost is compounded.