Inverter & water pumps

Robert

Stay Frosty!
Jan 2, 1999
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Has anyone had any experience using an inverter in an apartment building to power the water pump attached to a pressure tank.

Scenario:
Currently the building has a 3 phase, 5-8HP (label is hard to read) water pump connected to a 120 gallon pressure tank.

Based on the above, we would need to replace the pump, as I?m assuming you would need 3 inverters, one per phase if we wanted to use the existing pump. Plus the inverters would need to be very large to cope with the motor surges. Correct?

Plan B:
Has anyone ever seen a setup using a single phase motor connected to an inverter that could handle an apartment building?
If so, what specs, inverter size, etc etc?

Thanks.
 

GringoCArlos

Retired Ussername
Jan 9, 2002
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You are going to need a MONSTER generator to do this, and I am not sure that there is an inverter big enough to do this,even with 30 batteries. Water pumps are electricity hogs, and you have a BIG motor on yours.

On the plate on your motor, there will be a Letter code - ex: "A" "B" 'C' , etc , but just one letter. Tell me this, and I can get more specific.

Somewhere also on the motor tag, there will be a "wattage" rating. This is how many watts it takes to run this sucker, when it is RUNNING. It will take roughly 3X this wattage to start the motor up to run and pump water.

It's gotta be cheaper to put up multiple tinacos on the roof.
 

Timex

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May 9, 2002
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Single Phase.

You can't run separate inverters to make 3 phase.

But you can run a single phase, 120 Volt, 1 & 1/2 Hp, No problem.

Anybody who says no, can come to my house, and explain why my, Trace DR2424 with 4 batteries, last 4 days, while running the house the PC, TV, and a family that does not pay attention when the electric comes and goes.

My refrigerator, and hot water heater, are not on it.
My family of 4, takes 2 showers a day each, and my wife cooks, cleans, the house.

All using an on demand 1 & 1/2, pump, into a 70gal, pressure tank.

For work.
I just bought a 15Kva 3 phase, 220volts, UPS for a voltage sensitive, CNC.
20 minutes of back-up time, line voltage conditioner, $15,000. U.S $$$


Hope that helps.

Tim H.
 
Last edited:

lhtown

Member
Jan 8, 2002
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Three phase might not be technically impossible with three separate single phase inverters, but as I understand, they would have to be synchronized together so that there was no conflict between the phases. While it might exist and probably is technically possible, I have never heard of a commercially available solution for it.

Your best option (speaking inverter-wise) would probably be to change the pump to a 220v model and buy two Trace 2.4 kw DR series inverters with an appropriately sized battery bank. The two inverters can be linked with a parallel communications cable to syncronize the phases. The cable might not be available here, but I am sure it could be easily ordered or perhaps inprovised by someone techically saavy and connected to locally available inverters. That would give you 40 amps (at 115v or 20amps at 130v) of continuously available rated power- for safety and reliability, keep the load down around 3600 watts. If you read the ratings of the Dr series inverter, you will notice that they have a peak capacity (available for a few seconds) of about 3 times the continous rating which would give you power to start and run a 30 amp motor with no problems. In the event of overheating, they should just shut down and resume when they are ready (as I understand). In the event of overloading the bypass circuit, you would have to manually reset the circuit breaker. I don't know what happens if one inverter goes offline. It would be intelligent to force the other to power down also, but I don't know what happens. You might end up with 110v instead of 220 which might not be a good thing. If you keep the load down below 75% of rated load, you should never have a problem with overloading unless the pump malfunctions.

Be aware that your battery bank has to be capable of putting out that kind of power both in terms of total run time and peak current draw. Also, you will need to be careful to get cables that are heavy enough. I believe that with that setup, you could either use two separate battery banks or draw off the same bank. You might consider looking for a larger battery than the standard golf cart battery if you have a source to get them. Also, for the 16-30 batteries you will likely end up with, a battery filler ordered from Napa is a must unless you just enjoy filling batteries.

Disclaimer!
I have installed two inverters with large battery banks, but I have never tried to install or seen an installation such as you describe. It might not be practical, but it certainly should be possible with a 220v pump. Also, I as you probably already know, I am not an electrician. Good luck.
 

dprasociad

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Feb 9, 2004
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For DR1 Robert

Quote from JDJones
"It's much easier and less headaches to do the tinaco route)

One quick and dirty solution.
I have a friend who is car mechanics and this is what he did.

It works and it is cheap.

Can be used in many different situations.

a) pump water from a well
b) suck water from local water system.

First get plastic tubing
Second get regular car battery
Third get cheap battery charger
Fourth the secret ingredient: a brand new fuel pump for a car. These can provide lots of pressure
Fifth set-up a (part from toilet tank ) switch to turn pump on and off in the tank located on the roof.

Assemble everything so that it always (24/7) ready to operate,
Place the switch at a lower level in the tank than the main control switch.

Warning take shower in the morning when tank is full because it can take a long time to fill-up.

For the cost of an inverter you can install multiple copy of these; ( They are called the TAKI solution, TAKI is the inventor and lives on a small Greek island)

Yours.
DP
 

Robert

Stay Frosty!
Jan 2, 1999
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dr1.com
dprasociad said:
For DR1 Robert

Quote from JDJones
"It's much easier and less headaches to do the tinaco route)

One quick and dirty solution.
I have a friend who is car mechanics and this is what he did.

It works and it is cheap.

Can be used in many different situations.

a) pump water from a well
b) suck water from local water system.

First get plastic tubing
Second get regular car battery
Third get cheap battery charger
Fourth the secret ingredient: a brand new fuel pump for a car. These can provide lots of pressure
Fifth set-up a (part from toilet tank ) switch to turn pump on and off in the tank located on the roof.

Assemble everything so that it always (24/7) ready to operate,
Place the switch at a lower level in the tank than the main control switch.

Warning take shower in the morning when tank is full because it can take a long time to fill-up.

For the cost of an inverter you can install multiple copy of these; ( They are called the TAKI solution, TAKI is the inventor and lives on a small Greek island)

Yours.
DP

Thanks for the info, but I'm looking for solutions relating to my apartment building.
 

Bolt

New member
Jun 12, 2002
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www.wireless-alarms.com
I have discussed similiar options with our landlord many times as we also have a 220v pump on demand system for our apartment block.

In your case the situation appears to be quite one sided and if you want a cost effective invertor water supply I would definitaly go with tanks on the roof with ball valve shut off using a 110 pump. The on demand water system is probably the most expensive to run due to the massive surges required when a smaller pump can start and run far cheaper to a tank system. It also means if anything goes wrong there is always some water left in reserve. This is typical Dominican logic to fit the cheapest solution for the moment and dont give a thought on running costs!

A good 1.5 HP pump should give you around 7000 gallons an hour to least a 60/90 ft head so that would be ample for your needs but i dont know how many dwellings in your block as needs some calculations for tank sizes etc. But even if you went the 2 or 3 phase invertor route thats a lot of batteries that needs changing every 3 years. One thing we still have in our favour is cheap labour and tanks, piping and installation should be very realistic budget price.