Kill-A-Watt question

PhilS · February 2008

I've been unable to find this out by looking at the Kill-a-watt specs.

What's the minimum wattage that these measure?

Could I tell if my Monster brand surge protector draws any power by itself? I've seen posts here mentioning the 'standby' wattage of stereo amps. Will it measure that wattage even if it's small?

Phil

BB. · February 2008

Re: Kill-A-Watt question

1 watt is the minimum value it will display (and zero, of course)... I am not sure if it would totalize 0.5watt*10hours=5wHrs or not...

There is one thing to be aware of too... Many devices use capacitors and inductors for reduce RFI noise... They will draw current, but not power--sort of like pressing and releasing a spring takes effort, but by definition, there is no work being done (other than losses and your sweat).

So measuring current on a DVM may show current flow, but without measuring the voltage and phase--you don't know if you are being "charged" for it or not. Of course, with off-grid inverters--if you have enough of these parasitic loads, it is possible that the inverter will not go into standby (if your inverter supports this option).

-Bill

PhilS · February 2008

Re: Kill-A-Watt question

Thanks, Bill.

One watt is good enough for my uses.

Phil

backroad · February 2008

Re: Kill-A-Watt question

I've had quite a bit of fun with my Kill a watt meters. The stangest thing I found was my Direct TV receivers. Turned on and running they had a draw of 8 watts. On stby they were still using 7 watts.

Telco · February 2008

Re: Kill-A-Watt question

Mine finally came in yesterday. It's plugged into the fridge now, going to check when I get home to see what it used in 24hrs. It was bought new in 1995 and is due for replacement. The kids have been rough on it, and we never have been too happy with it.

PhilS · February 2008

Re: Kill-A-Watt question

Telco wrote: »

Mine finally came in yesterday. It's plugged into the fridge now, going to check when I get home to see what it used in 24hrs. It was bought new in 1995 and is due for replacement. The kids have been rough on it, and we never have been too happy with it.

"Refrigerator" is my latest project and one of the reasons I'm wanting to buy the meter. Sears is delivering an 18cf top freezer in a few days. 417 KwH/yr.

Propane on my double-RV unit (pictured) is at $50/mo and only going up.

Thanks crewzer for your help on this decision with the posts on YOUR fridge.

I'll probably have more posts on the subject but for now I was thinking I should have the Kill-a-watt to monitor the actual fridge usage and also see if there are any little loads that I should turn off, like the stereo in standby.

Phil

PhilS · February 2008

Re: Kill-A-Watt question

backroad wrote: »

I've had quite a bit of fun with my Kill a watt meters. The stangest thing I found was my Direct TV receivers. Turned on and running they had a draw of 8 watts. On stby they were still using 7 watts.

I've got the meter coming from NAWS. We have Dish network and I know just the receiver draws about 9 amps dc on the Prosine gauge whether it's on or off (but wait... the stereo, in standby, and some dvd players and the surge protector may contribute some).

Of course, when we are done using entertainment I switch off the entire circuit so the inverter goes into standby. But I'm curious if I could put some of the equipment (everything but the TV and Dish receiver) on a second switched power strip and save a little power.

Phil

backroad · February 2008

Re: Kill-A-Watt question

PhilS, you're right smack dab in the middle of what I found true. I finally made sure that all of my electrical items went to some kind of a switch except for the Fridge. The Satelite receivers, Tv's's, & computer went on surge protectors/power strips and are definitely turned off when NOT in use. Even the gas stove, now has a switch to turn it off when not in use because of the electronics.

There is a downside to completely shutting down the Direct TV receiver. It takes a little time to "reboot", acquire signal and udate the program menu. With three of the receivers in the house, that totals about 25 watts. Big deal? Not really, but it does all add up.

We have one of the 19cf Sears energy star frige's that averages about 1.15 kwh per day. We also have an 8cf Sears chest freezer that draws 85kwh a day. I quit using the Chest Freezer with the charging problems I've had, but will fire it back up with the 6 new panels are up.

System2 · February 2008

Re: Kill-A-Watt question

backroad wrote: »

I've had quite a bit of fun with my Kill a watt meters. The stangest thing I found was my Direct TV receivers. Turned on and running they had a draw of 8 watts. On stby they were still using 7 watts.

=============================================
Unfortunately the manufacturers and retailers of sat receivers don't seem to give a darn about unnecessary energy consumption. Many of the receivers, when turned "off" only kill the little red power LED and disable the outputs from the receiver, giving the deceiving impression that it's turned off. In reality, unknown to the customer, it's still going full tilt internally and helping to heat your home electrically.
As has been stated, use a switched power bar and just wait a minute for the sat receiver to get going again, when you turn it back on later.
Cheers
Wayne

crewzer · February 2008

Re: Kill-A-Watt question

Phil,

I received your PM. Cool news about the new fridge! :cool: I'm glad my reports were useful to you. I hope you'll post some performance data once it's up an running.

Regards,
Jim / crewzer

Telco · February 2008

Re: Kill-A-Watt question

Completed a 24hr check of the fridge, with the Kill-A-Watt hidden behind and no family members aware so it was normal usage. 2.1KWH for a 24hr period. Yep, guess what's going away? Way too much juice for the fridge. It's a Maytag RTP1900OAE, not sure what the cubic footage is anymore but I think it's around 18-19 cu ft.

LBergman · February 2008

Re: Kill-A-Watt question

backroad wrote: »

I've had quite a bit of fun with my Kill a watt meters. The stangest thing I found was my Direct TV receivers. Turned on and running they had a draw of 8 watts. On stby they were still using 7 watts.

I have a cable box that draws 16 watts when on. It draws 16 watts when off. Been meaning to ask someone at the cable company what the difference between off and on was (other then not getting a signal)...

BB. · February 2008

Re: Kill-A-Watt question

Many of the cable boxes, sat. and digital receivers are searching for updates, new channels and TV guides when "off" so that everything is updated when you first turn it on rather than needing to wait a few minutes to download a new copy.

-Bill

crewzer · February 2008

Re: Kill-A-Watt question

My digital cable box also draws 14 W continuously, or~2.4 kWh/week. :grr It doesn't matter if it's "on" or "off". The power button seems to control the A/V output jacks and the switched power outlet.

I believe that Bill's correct about the off/standby functionality. I'm thinking about connecting my cable box to a digital timer so that it's off overnight and when I'm away at work. But, I'll schedule turn-on times to give the box time to connect to the cable company, validate our account, and complete any downloads/updates. My calculation is that I'll cut energy consumption by ~50% or so.

HTH,
Jim / crewzer

LBergman · February 2008

Re: Kill-A-Watt question

That would make sense, BB. I usually unplug my box, only plugging it in when I'm ready to use it - then I get treated to frequent signal "glitches" and dropouts. I'm leaving it plugged in now to see if that fixes the problem. If so, I'm going to be disappointed - sure wish cable boxes weren't needed. (Need to get the box replaced anyway; now that I have a HD unit, I need a box to support it.)

BB. · February 2008

Re: Kill-A-Watt question

If you are aiming at 100 kWhrs per month (my totally impossible number to make--but one that off-grid folks and others serious about conservation do make), then 14 watts here and there can really make a difference.

100kWhrs per month / (30 days * 24 hours) = 0.139 kW or 139 Watts of continuous load.

14 watts is 1/10 of that target load. I have an older CD Stereo that takes about 30 watts on "standby". That is now on a switch too. My washer/gas drier take about 9 watts when "off"--I was able to cut their power usage by almost half by turning them off when not in use.

The lowest I run is around 200-225 kWhrs per month during spring... Those little guys really can add up.

-Bill

nigtomdaw · February 2008

Re: Kill-A-Watt question

My two pennies worth, in UK all mains sockets are switched however in Spain they are not. I deal with my TV and Sat Box and DVD Player in a novel way. The Sat Box and DVD player are all hidden in in a cupboard out of sight, the TV is mounted on a wall and powered from the hidden cupboard. I use one of those computer extension switches that has a master and several slave sockets .Only when the master (TV is switched on ) does the Sat and DVD become live. This is all completed by the computer socket being switched on and off by a hand held remote.

So with no external wiring I can press a remote with fires up the computer socket ,then switch on the TV which then powers up the sat and DVD. At the end of the night I hit the master off on the remote and this puts all the remote socket switches to off .

rplarry · February 2008

Re: Kill-A-Watt question

Telco
You may want to wait a bit before you send that refer back. The first 24 hours is the worst, let it run for a few days and check your Killawatt then. I think you'll find that it has settled down to a normal 1kw or so a day this time of year.
Good luck with yours,
Larry

BB. · February 2008

Re: Kill-A-Watt question

nigtomdaw,

But have you checked the power use of your remote socket in standby/on?

Seriously, I believe Wayne or Jim here had a bunch of X10 controlled lights and found out that the multiple X10 receivers were burning more power than was being saved by having the lights remotely controlled. Put 10 receivers and a base station in and you are probably burning 50 watts (I once looked for the X10 system power consumption online--but could not find it).

-Bill

BB. · February 2008

Re: Kill-A-Watt question

Also, regarding the new fridge... Make sure that you are not producing Ice and don't have the anti-sweat/door edge heaters on. Both take quite a bit of power.

And, it will probably take a few days for all of the fridge/freezer items to stabilize after the transfer. Especially if the new appliance runs colder and needs to cool down the foods.

-Bill

Telco · February 2008

Re: Kill-A-Watt question

rplarry wrote: »

Telco
You may want to wait a bit before you send that refer back. The first 24 hours is the worst, let it run for a few days and check your Killawatt then. I think you'll find that it has settled down to a normal 1kw or so a day this time of year.
Good luck with yours,
Larry

Heh heh, we aren't speaking about a new one, it was bought in 1995. It's definitely burned in. It gets cleaned regularly too. It's just old, and not an energy star appliance. When we do replace it I plan to take an initial reading, then another check a couple of weeks later.

Brock · February 2008

Re: Kill-A-Watt question

Wow this tread is all over, but great stuff.

I would agree on the fridge, let it settle for a day or two, it should get better.

On the X-10 stuff, it’s a tough call. I found each light switch to use about 2 V/A or about 3/4 watt when off. I have ours set to shut off everything every 4 hours, so if one of the kids left a light on catching it once will more then save the power used to keep it active. If lights are not normally left on it won't save power, but might still be worth it convenience wise.

The X-10 appliance stuff uses no power in the on or off mode itself, it uses a latching relay.

JetMech · February 2008

Re: Kill-A-Watt question

I think I'm going to order one of these in the morning. I'm curious now how much some of my appliances are using. For my kids' rooms I had originally used the motion sensor switches for their lights to try to avoid them leaving the lights on all day. It helped...at first. Then they would just slide the switch to manual and leave them on anyway. :roll:

BB. · February 2008

Re: Kill-A-Watt question

JetMech wrote: »

For my kids' rooms I had originally used the motion sensor switches for their lights to try to avoid them leaving the lights on all day. It helped...at first. Then they would just slide the switch to manual and leave them on anyway. :roll:

Ha Ha... That is the same thing that would happen in the various offices I worked in... People would break the switch, jam coffee stirrers under the rocker switch (with burned out the relay coils), or face a fan at the sensor to keep it on permanently, start using desk lamps, etc... Sitting at a desk usually did not provide enough movement to keep the lights on.

The only place it sort of worked... All of the engineers (especially the Software Engineers) that used to work really long hours on projects after the lights went out at 6pm (you would have to over-ride them every half hour) or those that would come in late--well, everyone just left at 5pm (even those that did not role in till noon)... Was a real downer--especially for the women--lights off every half hour except for a few glowing computer screens, no emergency lights (another story)... Productivity went down the drain.

-Bill

niel · February 2008

Re: Kill-A-Watt question

jetmech,
i think many of us can relate to what you're saying and going through to one degree or another. i had the problem of the cellar lights being left on and that area doesn't get visited enough by me to keep after everybody's leaving them on. i put a motion sensor light in and with the timer at about 5 minutes to shutoff it works out great except when the relay sticks inside. this happens occasionally, but at least they are only cfls. hmmm. maybe they defeated it too somehow for i don't know for sure. i would think one with a longer timer arrangement would be in order and i do not know if one with a longer timer is out there. if not maybe place a timer on a reading lamp that can go say 2 hrs to allow such still activities without leaving them going crazy every few minutes to put the light back on due to motionlessness. i have not pursued this farther to know what's out there so let us know what you come up with or maybe somebody else can chime in with their 2 cents.

System2 · February 2008

Re: Kill-A-Watt question

niel wrote: »

jetmech,
works out great except when the relay sticks inside. this happens occasionally, but at least they are only cfls.

=======================================
Interesting thought on this - - Many CFLs, when first turned on, demand a very brief, but intense inrush to charge up the capacitor(s) in their internal circuit. The electronically ballasted ones rectify the AC, producing 140VDC or so, and the internal inverter takes it from there, producing the greater than 10KHz AC that powers the CFL. In fact, I've played around with them some and the ones that don't have voltage doubler circuits will run just fine on 120VDC as well as AC. Just have to provide the right polarity. Why would I try such a thing? To find out - - and now I know. LOL
Some I have, produce a noticeable snap inside the wall switches when turned on. Could be welding the contacts in your motion sensor.
A one ohm fuse resistor in series may help? Just thinking out loud. LOL
Cheers
Wayne

mike95490 · February 2008

Re: Kill-A-Watt question

CFL's and X-10 controls.
I've found that to reliably use CFL's with X-10 appliance modules, you have to perform the "disable local sense" mod. Otherwise, with a surge in the line, it can trigger the module ON. Or, use the heavy duty appliance module, which does not have local sense. Before I did the mod's, I'd hear 3 or 4 clicks at once, as line noise triggered all the CFL's modules on.

rplarry · February 2008

Re: Kill-A-Watt question

Telco
I misunderstood, I thought you had just recieved your new sears refer, now I understand, sorry for the inapropriate response.
Larry

niel · February 2008

Re: Kill-A-Watt question

wayne,
initially when i first bought it i used up my incandescents on it and it did that with them firstly. usually i'd unscrew the bulb and let it rest awhile (day or so) and this usually resets it to operate properly until it acts up again. only paid $10 for the thing so i don't expect much from it and overall it is saving me as the rest of the family routinely leaves lights down there on.

Telco · February 2008

Re: Kill-A-Watt question

rplarry wrote: »

Telco
I misunderstood, I thought you had just recieved your new sears refer, now I understand, sorry for the inapropriate response.
Larry

No prob, you were not to know unless you read the first post I made on the first page, then remembered it a day or two later.

Further news, I was very surprised that the water bed heater sucks almost as much juice as the fridge, and we keep heavy comforters on it all day long. 1600 watts in a 24 hour period, and the bed is only kept at 79 degrees. The house is kept at 69 degrees for much of the day, and 72-74 during the times we like the heat higher. It would be 85 degrees in there all winter long if everyone else had their way though. Told the wife that we can keep the bed for now, but sometime in the near future we are losing the water bed. Gonna look at one of those Select Comfort jobs.

Hey, does anyone here have one of those select comfort beds? How much power does one of them use during the day? I'm assuming that the air pump has to run from time to time here.

mike95490 · February 2008

Re: Kill-A-Watt question

Telco wrote: »

I was very surprised that the water bed heater sucks almost as much juice as the fridge, and we keep heavy comforters on it all day long. 1600 watts in a 24 hour period, and the bed is only kept at 79 degrees.
Gonna look at one of those Select Comfort jobs.
Hey, does anyone here have one of those select comfort beds? How much power does one of them use during the day? I'm assuming that the air pump has to run from time to time here.

I went from a waveless water bed, to a temperpedic foam bed. I sure miss the warm waterbed. I had it's heater on a timer, for daytime heating only, no EM fields while sleeping. I had placed some foam board under the liner, to insulate the base. I have no idea what the power consumption was, but I sure miss the warm bed in cold weather. Other benefit was to lower the bed temp in the summertime.

I expect the air pump to only run a few moments per week, unless you get an air leak.

Kill-A-Watt question

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