thewireguy
Active Member
Could someone test a normal none communicating dimmer? I would like to see how they compare to a automated dimmer.
power consumption of automated light switches when OFF
- Thread starter electron
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Several years ago I looked into the standby power consumption of various dimmers, lamp modules etc. IIRC the higher prices dimmers were very efficient, drawing around 1 watt in standby and consuming a fairly linear amount of current as the lamp was dimmed. The standard x10 plug in lamp dimmers and x10 wall dimmers wasted a lot of energy both in the "off" position and when dimmed. I don't have my numbers anymore, but it seems that at a 25% dim level dim they were still eating about 70% of the full load energy.
I had two old mechanical dimmers I had removed when installing automation switches. Both have a mechanical Off position where there was no current flowing in my tests.
GE Slide Toggle Button when On at minimum 4.6 ma AC. .55W
Radio Shack 61-2699 Rotary Post type On at minimum 2.13 ma AC. .255W
As pointed out in a earlier post. Most modules use a capacitor in the AC input as part of the line derived power supplies so my current depending on my meter cold be off slightly. My Kill-A-Watt Meter didn't seem to be sensitive to read anything.
GE Slide Toggle Button when On at minimum 4.6 ma AC. .55W
Radio Shack 61-2699 Rotary Post type On at minimum 2.13 ma AC. .255W
As pointed out in a earlier post. Most modules use a capacitor in the AC input as part of the line derived power supplies so my current depending on my meter cold be off slightly. My Kill-A-Watt Meter didn't seem to be sensitive to read anything.
Well, if I did my math right with 70 devices in the house and assuming they each use 1 watt.
That gives me a yearly total of 613 KWH, at 22 cents a KW that ~$13.00 a year.
I guess that isn't too bad.
And the HS server is ~$60.00 a year.
Somehow I had feared it was a lot more than that, I probably spend more on coffee a year....
StevenE
That gives me a yearly total of 613 KWH, at 22 cents a KW that ~$13.00 a year.
I guess that isn't too bad.
And the HS server is ~$60.00 a year.
Somehow I had feared it was a lot more than that, I probably spend more on coffee a year....
StevenE
Just Another Joe
Member
Oops... slipped a decimal: 365@24 = 8760 hours in a year, so one watt running for a year = 8.76kWHr, and 70 one-watt devices would be 613.2kWHr. At $0.22/kWHr, that's $134.90.
A few years ago when I worked at UL we compared a few kill a watts to very expensive calibrated meters. There was no noticeable difference (less than 1%) so we all kept the ones we bought. For what they are they are a great device. They would never fly in an accredited lab but for home use they are awesome.
drozwood90
Senior Member
I agree...it's not a matter of how accurate the meter is (0.2%, 2%, whatever you find)...it's a matter of RESOLUTION! The meter might not be able to "see" at that low level.
I tried to plug my PPC into a KOW...it NEVER registered ANYTHING...
HOW much power is the KOW not seeing, as it's can not digitize enough resolution?
It uses a PWM signal generated from an OP-AMP to create it's registration of a unit of measurement...so how long does it wait between pulses before it decides that it didn't really read a pulse?
I'm not sure how SMALL it can see...but at least I have experience in it not seeing anything at all.
I'll try to get some time reading a switch with my Omega meter...it's accurate from 1uA - 30A.
--Dan
mustangcoupe
Senior Member
Not really... if the meter only measures down to 1 milliamp (which I do not know) current draw, and your device only draws 0.5 milliamps measuring it for 10-20 house wont matter because the unit does not have the resolution to measure low enough. now if you are talking accuracy then measuring over 10-20 hours would help.
Yeah, did see that and I have to laugh. Like this watt meter: http://www.elexp.com/tst_1522.htm It costs over $500 and has an accuracy 5 times worse at 1% +/- 2 digits. So if the device being tested actually draws 3 watts, the wattage read by the meter may be lower than 1 watt or higher than 5 watts and the meter would still be in-spec. Who would buy that?
So yes, I'm VERY sure this $25 device has a 0.2% accuracy from 0 watts to 1800 watts with all power factors over all temps. Yes, it says it so it must me true. Made in China and they never lie. Sorry, I don't mean to pick on those that don't have the engineering sense of some of us, but don't believe everything you read.
I knew my math sounded to good to be true, I did it by hand, while reading the board and helping my duaghter.... Maybe 1 task at a time next time..
StevenE
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