Panasonic PT-DZ12000U Operating Instructions Manual page 147

Use Ohm's Law to determine if your powerline is causing an
unacceptable voltage drop on your system.
V = VoIts
l = Amps
R = Ohms
Example: If you use a 400 foot length of 16 gauge powerline
to operate a vacuum pump that uses 3.7 amps calculate the
voltage loss using this equation; V = I x R
V = 3.7 x 0.4 x 4 = 5.92 Volts less than the standard 120
VAC at the source.
This causes your vacuum pump to operate with lower
efficiency and greater heat generation.
You must also consider the starting current of your vacuum
pump which may be three times its running current.
V = I x R
I = V / R
R = V / I
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