[RE-wrenches] Efficient step up, down transformers

[R Ray Walters]

I thought (based a previous thread) that we needed to be concerned with VA output of inverters, not wattage, at least on the transformer based machines like the SW.
I realize this wouldn't be an actual load if on grid.
In these situations, I just measure DC amps into the inverter to determine the actual consumption,  irregardless of power factor, AC efficiency, etc.

R. Walters
ray at solarray.com
Solar Engineer




On Jul 25, 2011, at 9:29 AM, Exeltech wrote:

> Measuring current without the phase relationship between the current and voltage
> isn't indicative of the actual power consumed.  Likely what you were seeing is the
> eddy current in the transformer core.  If so, it's 90 degrees out of phase with the
> voltage, and the real wattage consumed with no load connected is minimal.
> 
> Dan
> Sr. Engineer
> Exeltech
> 
> 
> --- On Mon, 7/25/11, Mark Frye <markf at berkeleysolar.com> wrote:
> 
> From
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