power back up for water pump

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I've got a customer wants a price for installing a generator back up for their water pump, this gives them water pressure within the house, (when the power goes off, so does the water), has anyone done this using deep cycle batteries, an inverter and a trickle charger?, either on a change over switch, or even set up to run permanently this way? just thinking that if this is the only thing they want the generator to run, the cost of the generator etc and the fact that someone has to go out and start it could make alternatives worth looking at??
 
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What sort of power level are we talking about? I'm guessing a few hundred watts if it's domestic but maybe much more if commercial.

What sort of duration does it need to be capable of running for? I assume the pump only has to run when water is needed.

An off the shelf UPS intended for computer use might be sufficient if the power and duration aren't huge...
 
If this was a new pump then I would recommend a 12v or 24v DC pump fed from trickle charged batteries. Avoided the cost of an invertor and change over unit. The pressure switch controlling the pump would need to be suitable for switching DC at the pumps rating.
 
could you not just use a UPS? You can get up to 5kva ones "off the shelf" for reasonable money. You can also add additional battery packs if you need to.

I would say this would be the simplest solution?

Edit: sorry, just seen that has already been suggested :)
 
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Not in a house but with a caravan I have set up pumps many times. The problem is turning the pump on and off. The simple way is a pressure switch and non return valve but running out of water can cause motor to run dry same if it freezes, the other is micro switches on taps fail safe but a lot of wiring.

With high rise flats it was common to have a booster pump but in the UK I am told it's not permitted to pump water from the mains. It has to go into a tank then be pumped from tank so if there is a leak on the mains only water goes out and dirt is not sucked in.

I have worked on farms where they use spring water and this is very different. The normal thing is to have a header tank with a float switch. The pumps then runs for set time to refill tank to upper level when float switch turns it off. With this set-up common to have DC pump connected to a lower level switch so if either main pump fails or can't deliver enough second pump kicks in. Normally some warning light tells farmer second pump in use.

Traction batteries with simple float charge are good enough for this. But where DC always used then a stage charger is used. The latter re-charges battery quicker.

With mains water boosting care is needed as if pump before the pump you are supplying also fails then it can suck dirt into the system.

So can you tell us a little more about what is required. With fire pumps we are not worried about sucking in dirt and clearly it must run far longer.
 
I've done quite a few private water supplies using wells, springs etc and would never pump directly into the house. You need at least one buffer / holding tank plus (except for deep wells) a settling tank. The "normal" way to get flow into the living areas would be a tank in the roof and/or fairly close to the house at a level to give several hours gravity feed with the pump controlled by a float switch. A booster can be used for power showers etc.
One very cheap backup pump system I put together was using a central heating pump (because it was there!), car battery, inverter and solar panel. Relays detect loss of mains. A flow switch checks that there is water going through the pump This has worked for several years without any problems or maintenance, so, if you already have a pump then a battery, inverter and charger (wind/solar/mains) should be sufficient. Apart from the usual water/electric considerations you'll need to think about animal damage.
 
One very cheap backup pump system I put together was using a central heating pump (because it was there!), c

What depth can they pump from, and head deliver water to?
I thought they were designed just to circulate water at effectively zero pressure?
 
depends on the pump...

They're all rated with a delivery head, so for instance a Grundfos 15/60 has a 6m delivery head.
 
Yes, the delivery head can be good, but they are not suction devices, so you need a small head of water. Not a problem with a spring supply, but no use for a well. As said, it was used simply because the householder had one laying about.
 
Cheers folks, there is currently a 1" pump operated by a pressure switch, one big tank on the hillside feeding two plastic tanks at the back of the property by gravity, the pump is between those and the house, but the power supply can be a little "unreliable", hence the possible back up system
 
Cheers folks, there is currently a 1" pump operated by a pressure switch, one big tank on the hillside feeding two plastic tanks at the back of the property by gravity, the pump is between those and the house, but the power supply can be a little "unreliable", hence the possible back up system
Maybe what the customer needs is a 'hydraulic solution' - switching the house's water installation to the tank on the hillside (with pressure limitation,if necessary) if the electricity fails (could even be switched automatically by electricity failure) :)

Kind Regards, John
 
Or just raise the tanks at the back of the property?
Indeed - but I assumed that, since they appear to be reliant on the pump, there must be some practical obstacle to doing that! To do as I suggested would only need a CH diverter valve and a little bit of plumbing.

Kind Regards, John
 
the tanks would have to be raised a lot, and there's no loft, the tanks at the rear also act as a reservoir and the pipeline from the large tank in the hillside is not of a large enough bore to supply everything at once, part of the property is used as a holiday let so dictating usage is not practical, hence the existing pump set up
 

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