Inverter brands

[booboo120]

Pump motor is a capacitor start; full load amp draw “measured” when the tank is full and the water table is at it’s lowest point, is 9.83, Amps, start-up inrush lasts .00256 seconds and is 28.62 amps. The generator notices the start-up but no up-throttling just a minor notice of sound change, the only thing that the generator sees as a 220VAC load is the water pump. I set the system up in the beginning with a slightly up-sized pump to minimize full load amps and inrush knowing the intent of the future. At the TDH “total dynamic head” of my system, I am more then adequate in operational sizing. It cost more up-front partially because it has 8 more stages then required, but is worked far less then the 1& ¼ Hp required to meet the TDH and it fills at 10GPM with no hassle. I have over the years run air compressors 3HP, at 110 VAC, table saws, radial arm saw, jointer, planer, band saw etc while building the actual house and living in a large camper while the wife was watching TV or whatever. The SW is a fine piece of equipment as far as I have seen. The information regarding the apparent differences between SW’s & XW’s was garnered from downloading the O & M’s from Xantrex and my original manual. I can clearly see a major weight difference and many adjustments are “or at least appear to be” no longer available.

[jeffkruse]

Page 4-3 of the Operation guide for the Xantrex XW inverter has a section about motors.

[Cariboocoot]

Pretty good guess on that start-up current, eh?

Good thing you "super-sized" that pump to begin with. Electric motors behave what seems like oddly to most people. Maximum draw is at stall, and even though 746 Watts is one electrical horsepower, it's not the same as "a 1 HP motor uses 746 Watts". In fact I have found that motor spec plates can be quite interesting works of science fiction.

So you have to be able to handle the start-up load of roughly 30 Amps for a fraction of a second. 30 A * 240 V = 7200 W. Fortunately the Xantrex inverters have very good surge handling capability. The XW4024 is rated for 8,000 Watts surge, so it should handle that brief 'blip' on start-up. I think there's enough margin for error there. I could be wrong.

[RCinFLA]

If money is tight, get a used 4024.

Also, check your pump to see if it has option to reconfigure jumpers for 120v.

Series stacking cable is pretty simple. I threw away the crappy ribbon cable they sell and made my own with data cables. The ribbon is just a reversal using 20 pins of 25 pin connector.

20 pins of DB25 connector used

1-> 23
2 -> 22
3 -> 21
4 -> 20
5 -> 19
6 -> 18
7 -> 17
8 -> 16
9 -> 15
10 ->14
11 -> no connect
12 -> no connect
13 -> no connect
14 -> 10
15 -> 9
16 -> 8
17 -> 7
18 -> 6
19 -> 5
20 -> 4
21 -> 3
22 -> 2
23 -> 1
24 -> no connect
25 -> no connect

pins 11,12,13 and 24,25 are open, unconnected on both connector sides.

[BB.]

You probably would have a difficult time doing accurate measurements with a kill-a-watt meter on 1/2 a leg of a 240 VAC split phase load--I would not recommend it.

Getting on of the whole house meters might be more useful (like a T.E.D. The Energy Detective or such)--However, I don't know how it will respond if the AC is turn on and off all of time (genset, inverter, etc.)--it may loose settings.

-Bill

[mike95490]

Page 4-3 of the Operation guide for the Xantrex XW inverter has a section about motors.

Tease.

(I have your answer here, but you must go to Xantrex and download the manual and look it up for yourself)

[RCinFLA]

Measuring the start up surge and its time is a bit tricky to catch accurately. It might be higher then the 28 amps you stated and longer in time. I use a closed loop hall effect sensor with 500 kHz bandwidth captured on a portable digital storage scope.

The 9.8 amps run current sounds about right for a 2 1/2 hp motor.

Anything over about 1 1/2 hp likely does not have a 120v/240v wiring option. A single 4024 will not likely start a 2 1/2 hp pump if you put it on a 120/240v transformer.

The SWplus allows a longer lasting surge then the SW or XW.

I have two 5548plus series stacked and two 4048 series stacked. The two 5548 runs my central air that has a start current of 120 amps for 400 millsecs, run of 13.5 amps @ 240vac. There is an output voltage slump on 5548+'s when A/C starts. The 4048's run the rest of house including refrig to isolate it from the voltage slump on the 5548+'s when A/C started. Originally with just the two 4048's, the A/C would trip an immediate overload alarm with inverters shutdown.

LRA spec on a motor does not assure that amperage is not exceeded. It is actually locked rotor amps at lowest operating line voltage spec, typically 208 vac or lower for 240vac motor. Actual startup current for a given setup depends on wire size and length of run to motor. My A/C compress has a spec plate LRA of 105 amps. Actual with my house wiring and line voltage of 240vac mains was 120 amps for 400 millisec.

I bought an electronic motor soft starter in attempt to get the start current down. Unfortuately, I could cut the peak start amperage by factor of 2 or 3 but only with side effect of a longer surge time for the lower amperage. Most induction motors will draw near LRA until they get very close to syncronous operation rotation speed. Once running the amperage is pretty constant (constant VA)over mechnical load range. Power factor improves as heavier mechanical load is applied.

[Solar Guppy]

The XW-6048 has a surge rating of 12kw ( 52.5 amps L to L for 15 seconds ) and starts and runs my old and new AC just fine. the old unit was a 4 ton SEER 10 PIG , pulled 4100 watts just running , the new 3 Ton Seer 15 unit pulls about 2700 watts.

Both run/ran just fine on the XW and I would put this inverter against anything previous or currently on the market. It usually not the inverter that can't handle the surge, its the battery bank or wiring buckling under the load.

Keep in mind, with the split phase units and being paralleled, you have options to how they turn on the slave units. With surges you would need to back off on the tar savings as they can't instantly respond to the load an inductive motor puts on the inverters.

[RCinFLA]

Solar Guppy,

I am not knocking the XW. It looks to be a fine unit. When my SW's die I will likely go with them.

BTW, I know the XW gives some DC amperes readouts, but one of the setup's give me the impression that the DC amperage readouts are not direct measurements with a battery line shunt but a calculated number from the AC input voltage and current and inverter AC load measurements.

Do you know the answer? The only reasons I ask is for lower DC charge currents a direct shunt reading will likely be more accurate then number calculated from AC input and load outputs voltage and current.

[peakbagger]

One thing to consider is to get rid of the pump starting surge by switching to a variable speed drive for the pump motor. They can be programmed for a real slow start so that there is no surge. Some of them also can be fed 110 VAC and they can output 220. Not sure if a capacitor start motor can deal with a drive but it may be worth checking.