# Power calculation disagreement

 Good afternoon, I tried what I thought would be simple power calculations, but the calculations are not balancing.  It seems that I'm doing something fundamentally incorrect.  Here's a hypothetical situation that illustrates the problem. There is a new 120/208 panel that has only one 2-pole breaker installed.  The load is 208 and the neutral is not used by the load.  The panel power meter shows line currents of 10, 10, 0.  The power factor is .90.  With the above readings, I believe the power for the panel (which represents only the one load) would be: Average of line currents * line voltage * power factor * sqrt(3) 6.67 * 208 * .9 * 1.732 = 2,162 Watts Then I go out to the field with my multi-meter and calculate power at the load: Line current * line voltage * power factor (assumed to be same as panel) 10 * 208 * .9 = 1,872 Watts. Why do I calculate ~15% lower power at the load? Thanks, Paul asked 6/30/2018 PBerry2

In order to provide an answer to this question, you must Login

## I am flagging this question because...

10 inform moderator flags remaining

## I am flagging this answer because...

10 inform moderator flags remaining

## Flagging a Post

You have already flagged this post. Clicking "Remove Flag" below will remove your flag, thus reducing the count by one as well.

## I am deleting this answer because...

Generator Sizing & Operation Limits

When selecting a generator, there are inherent limits on the active and reactive power which can be delivered. Generators are normally sized for a certain...

110 or 230 Volts

I've been considering a blog on the 110 or 230 Volt issue for a while.  While browsing the Internet I came across a great summary by Borat over at  engineering...

Generation of a Sine Wave

A fundamental concept behind the operation of alternating current systems is that voltage and current waveforms will be sinusoidal – a Sine Wave. This...

Battery Cars A to Z

Battery powered cars are a hot topic and widely debated. The pros, cons, issues and time frames can be talked about endlessly. An article by the Telegraph...

What happened to the cable notes?

If you are wondering what happened to our cable notes, the short answer is that we have moved them to myCableEngineering.com.  The "Knowledge Base" at...

Introduction to Current Transformers

Current transformers (CTs) are used to convert high level currents to a smaller more reasonable level for use as inputs to protection relays and metering...

Capacitor Theory

Capacitors are widely used in electrical engineering for functions such as energy storage, power factor correction, voltage compensation and many others...

Low Voltage Fault Tables

The following tables provide quick order of magnitude fault levels for a a range of typical low voltage situations.

Voltage Levels – Confused?

I was having a conversation the other day about voltage levels.  While everyone was in agreement that low voltage was 1000 V and less, there was more confusion...

Photovoltaic (PV) - Utility Power Grid Interface

Photovoltaic (PV) systems are typically more efficient when connected in parallel with a main power gird. During periods when the PV system generates energy...

Our website uses cookies so that we can provide a better experience.