Booster Pump Wiring

homwire

Member
Location
MA
I need to install booster pump in my house to increase water pressure coming into my house. Any advise where I can start to look for literature how to hardwire a variable speed pump? I have briefly exposed to wiring pumps in a class, so any tips will be very much appreciated.
 

petersonra

Senior Member
I need to install booster pump in my house to increase water pressure coming into my house. Any advise where I can start to look for literature how to hardwire a variable speed pump? I have briefly exposed to wiring pumps in a class, so any tips will be very much appreciated.
Before I would install a pump, I would be looking at why the low pressure situation exists in the first place.

I don't know of any variable speed pumps but you can get variable speed drives to feed a pump. I have never used one on a single phase AC motor though, or even seen one used that way, and since most single phase AC motors are capacitor started I am not sure just how well that would work.

Maybe get a three phase motor for your pump. You can often feed a variable speed drive with single phase and get three phase out of it.

Maybe a small PM DC motor and a DC drive would be more appropriate.

In the end it might be simplest to just buy a pump that has the right pressure outlet for what you need.

I vaguely recall there was a fairly recent thread about single phase AC variable speed drives. maybe a quick search is in order.
 
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cadpoint

Senior Member
Location
Durham, NC
Is your well incapable of suppling water or the pump lack pressure?
This was my first thought...

Anywas do you have a pressure gauge on the supply side(outlet) at the first point of usuage in the house? if so what does it read?

Who say's you need to boost anything? Is this a new house to you, you could be use to the old pressure could have be as high as 90 PSI, those nice strong showers and reactive water despening...

Most houses run at 60 PSI by design(that includes the fixtures) but can function as low as 25 PSI!

What is the PSI?
 
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I need to install booster pump in my house to increase water pressure coming into my house. Any advise where I can start to look for literature how to hardwire a variable speed pump? I have briefly exposed to wiring pumps in a class, so any tips will be very much appreciated.
I agree with others that question the need for a pump. As far as variable speed well pumps, there is an active thread going on right now.....http://forums.mikeholt.com/showthread.php?t=159648&p=1547748#post1547748
 

kwired

Electron manager
Location
NE Nebraska
OP doesn't need to have a private well as a supply to have pressure issues. I have seen booster pumps on municipal water supplied installations. Some where there was not enough pressure for flush valves to work properly for whatever reason, others where pressure was low in general because of elevation of the property, and others where insignificant supply lines was a problem. Insignificant supply lines still leaves you with some problems, but if the lines are on the municipal side of things, you may not have much choice but to put in the booster to at least increase performance to some extent. I ran a circuit to a booster pump once for a customer that had the city water tower literally right across the street. Supposedly they fought with the town for years about the water pressure issues but never could get anywhere. I don't know what the real issue was there, but they could not run much water at all without losing pretty significant pressure. The incoming line was smaller than what many newer lines are, 3/4 inch IIRC, but I have seen many other places with only 3/4 incoming lines with much better performance than this, so there was more to it than just that. The booster pump still left it with some undesirable pressure at times but was better than what they had before.
 

kwired

Electron manager
Location
NE Nebraska
A variable speed pump, or maybe better stated - a pump with a variable speed controller, would give you close to a constant pressure output - provided you are not using more than the capacity of the pump, and supply capability. This system may or may not require an expansion tank, but generally only needs to be a pretty small expansion tank if one is needed.

Non variable speed applications will need a pressure switch and expansion tank, more capacity of the system the larger the tank should be for best performance. There will also be a pressure differential that can be noticeable between cut in and cut out pressure of the control switch. This can lead to pressure quite commonly varying by as much as 20 PSI between cut in and cut out.
 

kwired

Electron manager
Location
NE Nebraska
I do agree OP needs to address why pressure is low in the first place, if he has a well and has worn out impellers in that pump, it would probably cost same at worst to just replace that pump. And a booster pump in the house is not all that desirable to have if not necessary, they are often noisy enough you just don't want one in the house.
 
I just need to add that there used to be such a thing as a variable speed pump but I can't find anything on the web. Maybe inexpensive VFDs have driven them to extinction. They were hydraulic and mechanical. Also there are some single phase VFDs on the market or you can feed a 3 phase VFD single phase input power and it will make 3 phase output. You have to size it based on the input amps required with single phase input. Most drives can do it.

w piper
 
Also, it is critical to understand pump operation when using a VFD. You do not want to have a pump sitting running at low speed and not generating any flow. It will get hot and fail. A variable speed booster system is doable but is more complicated than just sending pressure feedback to the drive and letting it run.

w piper
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Most dwelling unit booster pump systems consist of a pressure storage tank and the pump. The pump boosts the pressure in the tank and the tank supplies the water to the dwelling unit. The pressure switch starts and stops the pump to control the pressure in the tank...exactly how most well tank systems operate.
 

kwired

Electron manager
Location
NE Nebraska
Most dwelling unit booster pump systems consist of a pressure storage tank and the pump. The pump boosts the pressure in the tank and the tank supplies the water to the dwelling unit. The pressure switch starts and stops the pump to control the pressure in the tank...exactly how most well tank systems operate.
I'm with you on this one. There must also be a check valve in the line or the pressure will bleed back through the pump when the pump is not running.

If one were to put in a variable speed pump it could be done (and maybe is I just never seen such an install) similar to how constant pressure well systems are done, with a VFD, an expansion tank (only a small tank is necessary, but existing larger tanks are acceptable)and a pressure transducer, the drive varies the pump speed to try to maintain a fairly constant output pressure, does shut pump down completely when there is no water being used - a check valve is also necessary to prevent pressure from bleeding out through the pump when not in use.
 

Jraef

Moderator
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
I need to install booster pump in my house to increase water pressure coming into my house. Any advise where I can start to look for literature how to hardwire a variable speed pump? I have briefly exposed to wiring pumps in a class, so any tips will be very much appreciated.
The OP never says he has a well, I don't know where that came from.

Homwire,
Without knowing the REASON why you have low pressure (or even how that is defined), jumping into installing a VFD and a booster pump is like wondering how to get to the store faster and buying a Bugatti Veyron* first. There are a lot of details to investigate and steps to take before resorting to that extreme. For example if you have a municipal water supply coming to you via a pressure reducing valve, it may be as simple as turning up the allowable pressure at that valve. But if you install a pressure boosting pump, it will not likely make a difference, because the valve will not allow any more water to flow to the pump inlet anyway.

*Bugatti Veyron is (or was recently) the fastest production vehicle made.
 

homwire

Member
Location
MA
I need a booster pump because my house is next to town water tank. We have only about 20 something psi coming in to the house. Pressure is low and can't do a lot of things. The more I read about it, the more I realized that i would just go with single phase pump with storage tank to regulate the pressure rather than variable speed pump.

For a pump with 230v power supply, I would connect 2-wire #12 Romex as L1 & L2 with no neutral to 2-pole 20A breaker. My question is why no neutral? Don't we always have to have neutral to complete the circuit?

BTW, Kwired, what does OP stand for?

Thank you for all the info about pump.
 

ptonsparky

Senior Member
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
Electrical Contractor
OP=Original Post.

Now that we know your source of water is a municipal supply, we still need to know why your pressure is low. A restricted supply will not be helped by a pressure pump. Once the tank empties you will be out of water and the pump will not bring in any more than what is available.
 
Being next to the town tank shouldn't make pressure low. Is it an elevated tank? Being close to the source should make your pressure higher. The first step in solving a problem is understanding the problem. I like the PRV adjustment idea. But be careful. Somebody turned it down for a reason. Where are you measuring 20 psi?

w piper
 

kwired

Electron manager
Location
NE Nebraska
Being next to the town tank shouldn't make pressure low. Is it an elevated tank? Being close to the source should make your pressure higher. The first step in solving a problem is understanding the problem. I like the PRV adjustment idea. But be careful. Somebody turned it down for a reason. Where are you measuring 20 psi?

w piper
Could be that the tank is either buried or on grade with no additional elevation, but is on a hill giving it elevation in relation to most of those served by it, but OP situation is near enough that there is not much elevation above his location.
 

ptonsparky

Senior Member
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
Electrical Contractor
The village I used to live in had an area of town fed by a 1" water line. Adequate for a couple homes but not for what it grew to be. A few tried pressure pumps but they robbed what water there was from the neighbors so the Village stopped the installation of those. 6" water main is what solved the problem.
 
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