My VFD motors can change the world !

[kwired]

Both readings were at 240V, although the first reading on the old pump was not with a true RMS meter, and the second reading is off the VFD display.

That evens things up some compared to if original were 120 volts, but still remember that reading off the VFD is likely the output amps and will be three phase where the original reading was single phase amps. Also remember watts is the real number that means much for energy cost.

 

[Jraef]

That evens things up some compared to if original were 120 volts, but still remember that reading off the VFD is likely the output amps and will be three phase where the original reading was single phase amps. Also remember watts is the real number that means much for energy cost.

To his point here, reading the amps off of the VFD display is not the same as reading the clamp-on amps going directly to a single phase motor, because you have LOSSES in the VFD that do not show up as "amps" going out of it to the motor. But those losses would be part of the overall power being consumed.

 

[kwired]

To his point here, reading the amps off of the VFD display is not the same as reading the clamp-on amps going directly to a single phase motor, because you have LOSSES in the VFD that do not show up as "amps" going out of it to the motor. But those losses would be part of the overall power being consumed.

That is true but not the point I was trying to make. I have had those that don't know any better not realize that lower amps on a three phase motor means a whole lot. You will have more amps on a single phase motor of the same voltage rating but you are only splitting the power across one phase instead of three. Watts over time is what you are paying for not amps, amps can be relatively easily converted to higher or lower numbers and still use similar amount of watts