Check Power Usage with Multimeter ?

StratosFear · 20th September 2006, 2:17 PM

Hi guys,

I'm looking for a cheapish way to check the true power usage of a few computers in the house as well as other appliances.

Am I right in saying I can wrap the power cord around one of those Clamp Multimeters to get a read out of the current Amps being drawn and then use that simply to calculate usage?

If that is the case would this be okay? Is accuracy a concern?

If that won't work what are my alternatives?

Cheers.

nux · 20th September 2006, 4:49 PM

You would need to just put the clamp around the Active line with those clamp meters.

Jaycar has a power meter thats coming out soon: http://www.jaycar.com.au/productView...Max=&SUBCATID=

dohzer · 20th September 2006, 4:52 PM

Quote:

Originally Posted by nuxie1

Jaycar has a power meter thats coming out soon: http://www.jaycar.com.au/productView...Max=&SUBCATID=

Looks cool, but it'll suck when you have a power plug that doesn't fit in its socket.
I guess the problem would be easily solved with a generic power board/extension cable though.

StratosFear · 20th September 2006, 8:21 PM

hmm, thanks for that, looks good and not too badly priced. Might go with that.

StratosFear · 21st September 2006, 5:53 PM

Jaycar won't have it till december apparently

Anyone else sell them or something similar for the same price?

StratosFear · 21st September 2006, 6:45 PM

Quote:

Originally Posted by Chris Nolan

Can't you just turn one device on at a time and observe the meter?

Prefer not to, bit of a pain to run in and out across the house. For $40 I would be more than happy to use that little dohicky, but dont' really want to wait till december.

dakiller · 21st September 2006, 7:00 PM

Then use the clamp meter

Wrapping the active wire around the clamp a few times will multiply the value by however many turns, so you can push the reading into the more linear range of the meter

littlee · 21st September 2006, 7:58 PM

I can't think atm, but won't that only measure the apparent power (after you also check the voltage), not the true power?

StratosFear · 22nd September 2006, 5:33 PM

Quote:

Originally Posted by Chris Nolan

Then find someone else to help: you turn on/off the devices and the other person records the power usage at the swithbox. It only needs to be done once.

That will give me an average power usage but what about getting readings for peak power, minimum power usage etc for a computer for example.

Not very accurate. I would prefer to have a read out at that point in time in front of me.

Anyway will wait for Jaycar I suppose.

StratosFear · 25th September 2006, 4:28 PM

Quote:

Originally Posted by Chris Nolan

Good luck with the Jaycar device.

Thanks .

terrastrife · 25th September 2006, 4:42 PM

Quote:

OK, if you want to *really* measure your power usage, visit your local library and search for the "Home energy self-audit kit".
Among other things, it contains a Power Mate energy monitor - which is what I originally used to measure my usage.

maybe give that a go

20th September 2006, 2:17 PM	#1
StratosFear Member Join Date: Jun 2001 Location: Melbourne, Australia Posts: 7,686	Check Power Usage with Multimeter ? Hi guys, I'm looking for a cheapish way to check the true power usage of a few computers in the house as well as other appliances. Am I right in saying I can wrap the power cord around one of those Clamp Multimeters to get a read out of the current Amps being drawn and then use that simply to calculate usage? If that is the case would this be okay? Is accuracy a concern? If that won't work what are my alternatives? Cheers.

21st September 2006, 7:00 PM	#7
dakiller (Oscillating & Impeding) Join Date: Jun 2001 Location: SE Melb Posts: 6,156	Then use the clamp meter Wrapping the active wire around the clamp a few times will multiply the value by however many turns, so you can push the reading into the more linear range of the meter __________________ In memory of Cheers Z

21st September 2006, 7:58 PM	#8
littlee Member Join Date: Jun 2001 Location: Crazed Knife Stabbing Central Posts: 2,053	I can't think atm, but won't that only measure the apparent power (after you also check the voltage), not the true power? __________________ Say hello to my little friend.

20th September 2006, 4:49 PM	#2
nux Member Join Date: Jan 2002 Location: Melbourne Posts: 16,790	You would need to just put the clamp around the Active line with those clamp meters. Jaycar has a power meter thats coming out soon: http://www.jaycar.com.au/productView...Max=&SUBCATID=

20th September 2006, 8:21 PM	#4
StratosFear Member Join Date: Jun 2001 Location: Melbourne, Australia Posts: 7,686	hmm, thanks for that, looks good and not too badly priced. Might go with that.

21st September 2006, 5:53 PM	#5
StratosFear Member Join Date: Jun 2001 Location: Melbourne, Australia Posts: 7,686	Jaycar won't have it till december apparently Anyone else sell them or something similar for the same price?