i'm thinking 6 powerwalls would be sufficient. conventional wisdom says 10KVA per horsepower which would be 30KVA or 4 powerwalls.
does anyone have real world experience with this?
does anyone have real world experience with this?
How many Powerwalls do I need for a 3hp well pump
- Thread starter CrazyRabbit
- Start date
power.saver
Supporting Member
No, 1hp is 745W, or 0.9kVA. But it is the startup of load (LRA) of the pump that will determine the number of PWs needed.
Shygar
Member
If one powerwall can power my 2hp blender (plus entire house minus AC), I can't imagine you would need more than one powerwall and even that would be overkill.
I have a 10.5 kwh system with two Powerwall 2's and it has no problem with my 3hp well pump during power outages.
aesculus
Still Trying to Figure This All Out
As @power.saver pointed out it's the LRA plus all of your other concurrent loads that have to be considered.
The other factor is at what depth (ie how much real load) is being pulled to start that 3hp pump. When I had one active on a 1000 foot well it was a totally different story when the water table was high vs what it had to pull at 1000 feet.
The other factor is at what depth (ie how much real load) is being pulled to start that 3hp pump. When I had one active on a 1000 foot well it was a totally different story when the water table was high vs what it had to pull at 1000 feet.
sorry, i was talking locked rotor, not running power. but my well pump pulls 3.8KW (real power/not reactive) when running.
i believe mine is 300 feet, water is about 120 feet.
how deep is your well? do you have a soft start kit on it?
i believe mine is 300 feet, water is about 120 feet.
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aesculus
Still Trying to Figure This All Out
If your water is at 120 feet that is the "practical" depth of your pump as long as the well refills at or greater than your pump.
Each powerwall can sustain 5kW of power so if you really only draw 3.8 kW that is trivial. But again it's your starting draw that is probably going to be a factor.
But if you have 6 PWs that's enormous. You would think 2 PWs would be fine in this scenario.
6 PWs would be crazy expensive
3 HP is only 2.2 kW
Could startup be 3 or even 5 times? Then only 10kW required to start.
Way lower than 6 PWs
3 HP is only 2.2 kW
Could startup be 3 or even 5 times? Then only 10kW required to start.
Way lower than 6 PWs
it takes 30KVA to start a 3hp well pump and my well pump draws 3.8KW while running, not 2.2kw
yes i know 746w = 1hp
yes i know 746w = 1hp
Your blender is not 2hp, unless you have it on a special 120V/30A or 240V/15A circuit. Sounds like hp-inflation has come to blender marketing, just like it did to shop-vac marketing. If your blender has a regular 15-5 plug (the standard one), it's at most 3/4 hp, and probably less.
Cheers, Wayne
I think (3) Powerwalls should definitely do it, maybe (2) would work. My info:
It's going to depend partially on the startup load profile of what the motor is driving. If the load is low-inertia and comes up to speed quickly, then the starting surge will be over more quickly. If not, the starting surge may run long enough for the Powerwalls to exhaust their "surge" capacity, and you'd need to size them for starting based on their steady-state capacity I don't know enough about pumps to know what category a well pump falls into.
I have (2) Powerwalls and at commissioning we tried starting a 5 HP dust collector motor that is on a 40 amp breaker. It started to spin up but then the Powerwalls cut out, probably it was about 7 seconds and the Powerwalls decided the surge had lasted too long. After resetting, we tried starting my 3 HP tablesaw motor, no problem. And the tablesaw definitely comes up to speed a lot more quickly than the dust collector.
Hope this helps.
Cheers, Wayne
It's going to depend partially on the startup load profile of what the motor is driving. If the load is low-inertia and comes up to speed quickly, then the starting surge will be over more quickly. If not, the starting surge may run long enough for the Powerwalls to exhaust their "surge" capacity, and you'd need to size them for starting based on their steady-state capacity I don't know enough about pumps to know what category a well pump falls into.
I have (2) Powerwalls and at commissioning we tried starting a 5 HP dust collector motor that is on a 40 amp breaker. It started to spin up but then the Powerwalls cut out, probably it was about 7 seconds and the Powerwalls decided the surge had lasted too long. After resetting, we tried starting my 3 HP tablesaw motor, no problem. And the tablesaw definitely comes up to speed a lot more quickly than the dust collector.
Hope this helps.
Cheers, Wayne
Shygar
Member
7500 - Classic Blenders
I'm not sure why they would say that if physically it's impossible to be over 3/4 on a regular 15-5 plug.
It's marketing.
Look at the specifications page, it lists 2.2 HP "peak". That "peak" modifier means "we took the single point in time during either the motor's startup, or if you overload the motor until it stalls (I forget which) at which the current draw peaked, calculated the instantaneous power consumption in HP, and got 2.2 HP."
But motors are typically specified by their continuous mechanical power output without overheating. For that motor I would guess it to be in the 1/4 HP to 1/2 HP range, but I'm no expert.
Cheers, Wayne
at 2.2 hp it would boil water faster then your microwave. lol
Tesla engineer thinks 6-7 powerwalls will do me fine... need 4.1 powerwalls at surge capacity to start.
they are discounting (-9500) for up to four powerwalls with solar now. the rest would be full 6500 price.
Tesla engineer thinks 6-7 powerwalls will do me fine... need 4.1 powerwalls at surge capacity to start.
they are discounting (-9500) for up to four powerwalls with solar now. the rest would be full 6500 price.
Would adjusting your well pump setup to a smaller pump or something driven by a VFD or similar be a cost effective solution? It would reduce the starting surge and thereby reduced the number of Powerwalls you need.
Cheers, Wayne
Cheers, Wayne
I have seen 9KVA peak generator work well for 1.5 HP pump so 21KVA peak (3 PW's) maybe enough for 3HP pump.
My 7kW generator (7.5kW surge) runs my 1.5 HP well pump fine. I used it for several years before I had power to my property.
I'm getting 2 Powerwalls and sent Tesla all the information on the well pump. They didn't have a problem with it.
It seems like 4 Powerwalls should be more than enough.
I'm getting 2 Powerwalls and sent Tesla all the information on the well pump. They didn't have a problem with it.
It seems like 4 Powerwalls should be more than enough.
