We are building a new house, radiant slab for heat, and I’m just trying to decide what well pump to put in. Have heard many recommendations for a Grundfos variable speed pump, because of its energy efficiency, soft start, etc. Our driller, who also installs pumps, doesn’t deal Grundfos, but said he has a Franklin Electric constant pressure controller, that can do the same thing using a regular well pump. Does anyone know anything about these units or have a recommendation?
thanks-
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I have the Franklin in my home up north. I spec'ed 2 more in houses that I manage(very high water use). When my pump dies here, I will install the 4th. It's the only way to fly.
The Grundie is more money and has a few more bells and whistles. You won't go wrong with the Franklin.
thanks-
we are not anticipating high usage; our well is 7-8gpm and there's just the 2 of us (and the garden). Interestingly, his price for the Franklin controller and a pump is about the same as the Grundfos, maybe even a bit higher (unless I misunderstood).
The space you save for the water tank is a bonus.
You'll be happy.
Franklin's Monodrive is a variable frequency controller as well. If your well guy does Franklin, I'd go with it. They're a pretty respectable name.
Mind you, I've supplied 25 or 30, 175 and 200 hp Franklin submersible motors on a mine dewatering project, so I'm familiar with their products.
anrl,
I don't have any experience w the drive/motor combo you are talking about.
I have installed and serviced many FE motors in the 10 to 50 HP range. In our application, we would run them for days/weeks continuously,,, this was not residential.
The motors we ran had a hydro dynamic thrust bearing at the bottom of the motor. This bearing took the axial thrust from the pump, and any other axial loads on the motor/pump unit.
My thinking was always that these motors had the best life running at full speed, and starting and stopping as infrequently as possible.
In your case I would be inclined to go w the largest pressure tank you have space for, and just start the motor across the line. No soft start, no variable speed drive.
Does not seem the two of you, and your garden, are going to have big issues w minor pressure fluctuations.
Ask your well driller what the most common set up is. Ask him what gives the longest and most trouble free service.
Best of luck, Harry
I have a ground-source heat pump that uses well water as its source and have considered going to one of the variable speed pumps if my current pump fails. I'm glad to hear of successful use.
What I don't understand is how Franklin can retrofit a variable speed setup using the existing single phase pump?? I thought that all the variable speed pumps were multi-phase (3 phase). It seems to me you'd need to replace the pump and wiring (you'd need at least one additional conductor for 3 phase right?)
A variable speed drive works by changing the frequency of the power. 60Hz is standard, if you change the frequency to 50Hz, the pump runs half the speed.
There are 3 phase and single phase VFDs. There are also VFDs that can take single phase input and controla 3 phase motor.
Thanks HammerHarry. Just to be clear though, you can't vary the fregquency to a standard single-phase well pump and expect it to work properly can you? Does it require a specical pump motor? That way, you replace the pump motor, add the variable frequency drive and you're set?
Consider before you buy a pump that variable speed pumps and/or automatic throttling valves aren't compatiable with any private well chlorinating equipment (pellet dropper or liquid injector) that I've seen or am familiar with. ( Local plumbing supply house doesn't know of any that are either.)
This because the chlorinators run whenever the pump is running....and only when the pump is running. A variable water delivery rate per minute from the pump would make it impossible to set the chlorinator to dispense the right amount of pellets or liquid.