well pump surge kicking breakers

[dunay]

Hi,

I have a question about a well pumps.  I have two of them, powered by a 48volt magnum inverter.  The magnum's surge rating is around 8500 watts.  

Here is the problem:  When one well pump is operating and the other surges to turn on, I exceed the rated watts on my inverted, which trips the breaker.  The breaker has been properly sized to the inverter.

One solution would be to install slow start high efficiency well pump, however being less then two years old, i'd like to find a different solution.  If I could get past the surges of the well pumps, the inverter would be able to handle there normal operating amps (around 8 amps each).  Has any one heard of something similar to a power conditioner that might help me slow the surges of the well pumps?  Or maybe a capacitor  setup that I could install?  Both well pumps are 240VAC.  I have the magnum inverter hooked up to a 2.1kw solar array.

Any thoughts would be appreciated.

Matthew Dunay

[bob g]

is there a reason why both pumps have to run at the same time?

seems like either a electomechnical relay system or logic control could be used to lock out one pump if the other is running.

that is unless you have to have both running at the same time?

bob g

[dunay]

No, I don't have to have both pumps running at the same time, but I hadn't thought to limit both from turning on.  Still, i'd like to find a way to be able to run both.

[bob g]

the reason i asked about whether or not you needed them to run at the same time

is system reliability.

in my opinion, not having any control over when the pumps run and most particularly when the both start can present even more issues that you have encountered so far.

without some sort of control, how will you be certain that both pumps don't decide to start at the same time, let alone one running and one starting?

it would seem to me having some control over the start/run of these two pumps would make the system more dependable and less costly in the initial investment.

i don't know what the starting amps are for your pumps, but if both decided to start at the same time, i can see the amp draw exceeding your 8kwatt surge (after going back i see you are exceeding that with one running and the other trying to start)

personally i think you are going to have to go either with a much heavier inverter system, or embrace some form of control.

so basically even if you come up with a method of running one and getting the other to start without tripping the inverter, conceivably there will be a time when both start at the same time and trip the inverter anyway.

without control you have to plan for the absolute worst case scenario, it is something related to "murphy's law"

bob g

[wpowokal]

Matthew, previous comments seem to nail it but just to cover all bases what size battery bank do you have? You tell us about your solar panels but not the batteries.

There are capacitor/relays devices available but without telling us the type of well pump ie a submersable or other, recomendations on starting devices is not possible.

What are each of these well pumps doing?

You say the breaker has been properly sized to the inverter, there are different curves for breakers, is it a breaker that can stand the surge current for correct starting time?

allan down under

[wooferhound]

Here is a story almost about the same thing

Refrigerator surges

but the help will be the same as your situation

http://www.fieldlines.com/story/2008/5/23/115041/076

[Ungrounded Lightning Rod]

Have you investigated whether soft-start controllers exist for either or both of the pump motors you currently have?

[FuddyDuddy]

If the two pumps are doing the same thing (IE, both supplying water?) you might consider an "Alternating Relay". They are available through eBay for about $50.

They switch from one to the other, but always select "A" on "voltage on".

Like a duplex pump control panel. When the run command comes in, "A" runs. On the second command, "B" runs, etc. They are available in different voltages.

FuddyDuddy

[dunay]

Thanks for the info.

I like both the alternating relay idea as well as the Hard-start capacitor idea.

The array is 2.1kw and the battery bank is 480amps @ 48volts.

The pumps I'm not so sure about.  I believe both are 1hp pumps, submersible.  While running, both draw 8 amps, but while starting one draws 17amps and the other 22amps @ 240V.  I am using both pumps for domestic water.  

Are the hard-start capacitors something that would be installed on the hot leads to the pumps?  Or is this something that would involve pulling the pumps out of the wells?

[wpowokal]

Facts so far..

Magnim 4.4Kw inverter 5 sec surge of 8.5Kw

Batteries 48V 480 amp/h

2Kw solar system

Two 2Kw (2.6HP) submersable pumps (8A @ 240V)

Pump #1 draws 17A (4.25Kw) instantanious amps on start up.

Pump #2 draws 22A (5.5Kw) instantanious amps at start up.

When one pump is running and the seconds starts the inverter breaker trips..... thank goodness for breakers.

Alternating relay is your only option.

I would never put a hard start relay on a subie, they are designed to complement the starting capacitor by being switched in briefly at start up. You would need to discover if they are 2 or 3 wire motors, by your start amps it sounds like one of each. Two wire motors are harder to start than a 3 wire that will have a start box above ground, if they are 3 wire have the capacitors checked.

That inverter/battery/solar system would be battling to run both pumps (4Kw of inverter capacity of 4.5Kw). Both my 3Kw inverters have a 9Kw surge rating I know nothing of your inverters design but it does not have a very good surge capacity.

You don't say why both pumps need to run at once, is this your own system or that of a client?

allan down under

 

[hayfarmer]

old post,don't know if mat is still around but this might be helpful to other members.I have the same inverter Magnum AEMS4448 inverter with a well pump ,I replaced my pump

 
about 7 years ago ,it was a jacuzzi 1/2 hp with a 3/4 hp   6.8 AMP 230v pentan pump .not being a plumber and thinking bigger is better, added 130 feet to pipe and wire to




its current depth of 340 feet .it has been working fine with both well pumps at 210 feet 1/2 hp and 340 feet 3/4 hp. my questions are  1) what depth is pump at? is the 1 hp 




over kill?  2) you stated "When one pump is running and the seconds starts the inverter breaker trips..... thank goodness for breakers" is this the breaker tripping on the




magnum  inverter, or is it the circuit breaker on the A.C. breaker panel going to the well pumps? 3) you don't have both pumps on the same 240 volt breaker circuit exceeding




the amp capacity of the wire and breaker out to well? I like to hear the end results of problem solving, hope yours was fixed.


  hayfarmer