ax draw while running is 13A or 17.7A depending on where the spec comes from.I suppose if the outlet is rated for 15A, thats cutting it close at 13A. Since its variable speed I wouldnt expect a huge spike in startup current though.
Why?
15A vs 20A
- Thread starter Darin
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This is true but this motor is on a controller/VFD/soft start. So start up is not a problem if started properly. I assume the programmer used a ramp up at the factory.
- Jul 21, 2013
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Does not matter. The wiring must be for the manufacturers specified amperage.
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If you have 12 AGW conductor already, just put in a 25 AMP GFCI breaker and a 25 amp plug with 25 amp receptacle and you are good to go if you can get the correct breaker for you panel. No need to switch to 220V that way.
No. there is no efficiency difference in single phase 120V vs. 220 V. watts are watts. P = V x I
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- May 23, 2015
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True as well. But this VSP motor is from a "cheapo" manufacturer ... there's not telling what they did or how they programmed the VFD. Even the VFD can have a big in-rush current as it charges up the capacitor bank for intial startup and speed changes. If the RC time constant isn't appropriately designed for the load, you can get huge bursts of current. A lot of VSP's also use a priming startup sequence (my IntelliFlo does this) where the pump is driven to full-speed for a fixed period of time to get the pump primed (even though my pump doesn't need priming). In the case of the Pentair pumps, you can limit the max speed, priming time, and priming sensitivity to achieve a quick startup. Not sure if the V-Green motors do that ...
But @ajw22 is correct, no matter the design, the wiring has to be rated to the manufacturers max current spec.
Understood, not a full on start, but rather a ramp up. Thus lower inrush current.
Looking at the spec sheet the amperage draw is much lower on the 230V is what I assume he meant
- May 3, 2007
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I agree with these points that @Darin has made because they are true:
- A VS motor that uses slow start, which I think almost all do these days, there is very little "in-rush" current. That is the point of slow start in a VFD.
- There is no efficiency difference in single phase 120V vs. 220 V. watts are watts. P = V x I
There might be some small efficiency difference in the wiring to the pump but if the wire gauge matches the breaker amp rating and maximum amp draw (14-gauge vs 12-guage), there is very little difference.
Also, VGreen motors are made by Century (Regal) and they are pretty sophisticated and can now support many different manufacture controllers.
- A VS motor that uses slow start, which I think almost all do these days, there is very little "in-rush" current. That is the point of slow start in a VFD.
- There is no efficiency difference in single phase 120V vs. 220 V. watts are watts. P = V x I
There might be some small efficiency difference in the wiring to the pump but if the wire gauge matches the breaker amp rating and maximum amp draw (14-gauge vs 12-guage), there is very little difference.
Also, VGreen motors are made by Century (Regal) and they are pretty sophisticated and can now support many different manufacture controllers.
It became it's own discussion IMO, derailing your thread.
I am in no way(s) perfect, but I assure you I'm trying my best to help keep things flowing smoothly.
sktn77a
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- May 23, 2015
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Electrical resistance heating, aka, Joule Heating, is a microscopic phenomenon. The heating is caused by the flow of electrons (particles with energy associated with them, not waves ... but let's not get into quantum mechanical arguments) through a material conductor where the electrons undergo energy loss due to scattering from defects, crystal grain boundaries, impurities, etc, etc. When the electron is scattered, it deposits some of it's energy into the crystalline lattice as phonons (quantized vibrations of the individual atoms). Phonon energy is directly related to temperature and heating.
Therefore, if the power is expressed as I2R, then anything you can do to lower the current, I, greatly helps reduce the Joule Heating because you have fewer electrons flowing and banging into things inside the conductor. This is why 220V is preferred because it allows you to deliver the same power but at lower current which then allows you to reduce the size of the conductor. Since there is less current, there is less Joule heating and lower loss. Now, at higher voltage the individual electrons have higher energy, but there isn't an exact trade-off between the energy that the electrons deposit and the numbers of them flowing inside of a conductor. Because collisions inside the conductor cause greater energy deposition into the lattice as opposed to energy being coupled into the lattice by non-phonon processes, you get less heating even though the power is the same.
Westinghouse and Edison would be very proud of the arguments we are making in this thread ... but we all know who won the AC-DC power transmission wars
Therefore, if the power is expressed as I2R, then anything you can do to lower the current, I, greatly helps reduce the Joule Heating because you have fewer electrons flowing and banging into things inside the conductor. This is why 220V is preferred because it allows you to deliver the same power but at lower current which then allows you to reduce the size of the conductor. Since there is less current, there is less Joule heating and lower loss. Now, at higher voltage the individual electrons have higher energy, but there isn't an exact trade-off between the energy that the electrons deposit and the numbers of them flowing inside of a conductor. Because collisions inside the conductor cause greater energy deposition into the lattice as opposed to energy being coupled into the lattice by non-phonon processes, you get less heating even though the power is the same.
Westinghouse and Edison would be very proud of the arguments we are making in this thread ... but we all know who won the AC-DC power transmission wars
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The R in I^2R can change as well with external electrical wiring between 12-gauge (20A) and 14-gauge (15A) wiring so it isn't just about the current.
Also, in dual voltage VS drives they design for both the maximum voltage (240v) as well as maximum current (120V). The first stage of the VFD is an AC to DC converter. So the DC bus voltage is different between the two input voltages but the way dual voltage VS motors adjust to the difference in voltage input is to change the PWM duty cycle for each input voltage type. So in effect, the RMS voltage from the PWM waveform that is going to the 3-phase motor is basically the same between 120v and 240v which in turn means that the RMS current and efficiency are the same for the two voltages as well (within the motor).
Also, in dual voltage VS drives they design for both the maximum voltage (240v) as well as maximum current (120V). The first stage of the VFD is an AC to DC converter. So the DC bus voltage is different between the two input voltages but the way dual voltage VS motors adjust to the difference in voltage input is to change the PWM duty cycle for each input voltage type. So in effect, the RMS voltage from the PWM waveform that is going to the 3-phase motor is basically the same between 120v and 240v which in turn means that the RMS current and efficiency are the same for the two voltages as well (within the motor).
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Using 240 volts vs. 120 volts reduces power losses in the supply wiring by about 4 times.
If your voltage drop is 3.6 volts, then you lose 54 watts in the wiring at 120 volts at 15 amps.
For 240 volts, the voltage drop will be half at 1.8 volts and the current will be half at 7.5 amps, which means that the power lost in the supply wires is 1/4 at 13.5 watts.
The power efficiency of a single speed pump or variable speed pump should be about the same.
If your voltage drop is 3.6 volts, then you lose 54 watts in the wiring at 120 volts at 15 amps.
For 240 volts, the voltage drop will be half at 1.8 volts and the current will be half at 7.5 amps, which means that the power lost in the supply wires is 1/4 at 13.5 watts.
The power efficiency of a single speed pump or variable speed pump should be about the same.