Why does a 0.5 HP 240V pump draw 4-5 amps instead of 1.55 amps?

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Evil Bunny
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A coworker has a well pump that is a 0.5 horsepower, brand new, no issues...

He says the normal amp draw is 4 to 5 amps.

This is puzzling because it is a 240V pump and the math works out to (746/240 = 3.1/2 = ) 1.55 amps.

What is going on?
 
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maybe it's the, i don't know English term for it, phase shift between current and voltage. E.g. if the current is 90 degrees off phase, the power (given by integral of voltage times current over entire cycle) will be 0 no matter the current. It tends to happen with inductive loads. It can be compensated for by connecting a capacitor in parallel.

Read this article:
http://en.wikipedia.org/wiki/Power_factor
 
Yep... I was forgetting all about power factor and efficiency. Don't I feel stupid now...