[RE-wrenches] Power-Save and Power Works

[Peter Parrish]

This is a pretty important measurement. I was hoping that the Power-Save was
eliminating the out-of-phase current, leaving only the in-phase component.
But if it throttling down the in-phase current as well, that's another
story. It would be nice to know the Power Factor in both cases, which would
answer the question.

 

Let's assume for a moment that the Power-Phase does eliminate the
out-of-phase current, but not the in-phase current.The immediate question
that comes to my mind is "Are the current specs for an inverter (continuous
and surge) based on in-phase current or the total current, part of which is
in phase and part out of phase?" I suspect it is the latter (total current).
In which case the Power Phase (or its equivalent) would be useful in
presenting lower (motor based) surge currents to an inverter.

 

Another question that I have thought about every since I bought my first
Kill-a-Watt, "Is there a similar version for 240V loads? I suspect that one
could kludge two 120V Kill-a-Watts together in a j-box and make it work some
how, but a real 240V version at a reasonable price would be great news.

 

- Peter

Peter T. Parrish, peter.parrish at calsolareng.com 

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From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Jeff Yago
Sent: Sunday, August 24, 2008 8:56 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Power-Save and Power Works

 


On start up, the A/C unit went up to 91 amps and leveled out at 13 without
the Power-Save 1200 on. When the Power Save unit was engaged it was a draw
of 35 amps and leveled out at 8.75. That pretty much blew everyone away!
After that, I tested everything with a motor load in my house. I was
astonished at the significant reduction in amperage.
 - - - - - - - - - - - - - - - - - - - - - - - - - 

 

You note they are not measuring the output of the device being connected.
For example, they are reducing the current draw of the motor in the AC unit
by slowing it down a little, which will reduce the cooling output by same
percentage.  Like a variable-speed-motor drive, yes you can reduce the motor
current draw, but you are also slowing down the fan, pump, or compressor it
is driving.  Only time this may be an advantage is if you want to reduce the
output of the device being driven as part of redicing its current draw.

 

Jeff Yago


 

  _____  

Netscape.  Just the Net You Need.

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