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Nullus Anxietas |
Rather than drag another thread off-topic... Referring to this post by stoic-one: Re: Question: Can I use this Speed Control with this electric motor?:
Hmmm... I hadn't thought of a soft-start controller for our well pump. When I first bought our generator I sized it for the running and starting loads we had at the time. We subsequently replaced the 2 in. jet well we had, that had a pump with a 120VA, 20A motor, with a 5 in. well. It has a 1 HP, 18 GPM, 240VAC, 30A pump down there. When that thing comes on it drags the generator right down into the mud. Bad for the generator. Bad for anything else that happens to be running at the time. Unfortunately, Generac no longer makes generators like the one we have, and I haven't been able to find one with similar performance specs that wouldn't cost an arm-and-a-leg. A soft-start controller for the well pump might solve the problem for us neatly. Anybody know anything about this subject? "America is at that awkward stage. It's too late to work within the system,,,, but too early to shoot the bastards." -- Claire Wolfe "If we let things terrify us, life will not be worth living." -- Seneca the Younger, Roman Stoic philosopher | ||
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Ammoholic |
You mean hard start kit? It's just a capacitor. Tried to find one online that includes some kind of enclosure or something that would allow you to wire it inline. Only thing I could find are the ones for A/C units which go inside of A/C wiring compartment. Jesse Sic Semper Tyrannis | |||
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Nullus Anxietas |
No, a soft-start controller, as per stoic-one's post. "America is at that awkward stage. It's too late to work within the system,,,, but too early to shoot the bastards." -- Claire Wolfe "If we let things terrify us, life will not be worth living." -- Seneca the Younger, Roman Stoic philosopher | |||
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Member |
What you want is a VFD Variable Frequency Drive. ——————————————— The fool hath said in his heart, There is no God. Psalm 14:1 | |||
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Unflappable Enginerd |
A hard start and soft start are as different as a SS vs. VFD. This is what I used, you just need to buy the proper size. http://www.hypereng.com/ Single phase stuff here: http://www.hypereng.com/single_phase.html They're designed to be used with capacitor start, induction run motors. But as noted, you would need somewhere to mount it, I have no idea what your setup is... __________________________________ NRA Benefactor I lost all my weapons in a boating, umm, accident. http://www.aufamily.com/forums/ | |||
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Nullus Anxietas |
That looks like it may be the ticket. Thanks! Mounting space won't be a problem. There's plenty of room in the corner in which the expansion tank, pressure switch, and local disconnect switch are located. What I don't know is where the motor start capacitor is located. If it's down there at the bottom of the well, which is what I suspect, then, as per the wiring diagram on that page: Won't work. I've also a call into our well guy. "America is at that awkward stage. It's too late to work within the system,,,, but too early to shoot the bastards." -- Claire Wolfe "If we let things terrify us, life will not be worth living." -- Seneca the Younger, Roman Stoic philosopher | |||
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Unflappable Enginerd |
Yeah, that might be a problem if the start capacitor is built in to the motor, which I suspect it is. Might could try one of these: https://www.ato.com/single-phase-vfd Unfortunately, single phase motors on a VFD usually need to be de-rated, so it's not necessarily a win win situation. __________________________________ NRA Benefactor I lost all my weapons in a boating, umm, accident. http://www.aufamily.com/forums/ | |||
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Member |
Check these guys out. They seem to know soft starts on electric motors https://www.microair.net/produ...?variant=30176048267 | |||
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Nullus Anxietas |
Thanks, but still requires direct access to the start capacitor. "America is at that awkward stage. It's too late to work within the system,,,, but too early to shoot the bastards." -- Claire Wolfe "If we let things terrify us, life will not be worth living." -- Seneca the Younger, Roman Stoic philosopher | |||
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Nullus Anxietas |
Talked to my well guy. Yes, he's installed single-phase soft-start controllers for existing installations like ours. He uses, tah dah: A single-phase VFD. Problem is: The VFD would be $1400 + labor. Since our pump has 22 years on it, he thinks this not the wisest investment. So I think what we're going to do is work with what we have. What I now do when we're on generator is keep the pump disabled until the water pressure gets too low. Then I shut off the other high-load stuff, turn on the pump, let it charge the expansion tank, shut it back down and turn the other stuff back on. It's inconvenient, but works. Then, when the current pump needs replacing, we'll probably replace it with a slow-start pump (I think Grundfos is the brand he mentioned). That would also be around $1400 + labor, but replacing the current pump with a like pump would be $850 + labor, so not such a big differential. Thanks for the feedback, y'all! "America is at that awkward stage. It's too late to work within the system,,,, but too early to shoot the bastards." -- Claire Wolfe "If we let things terrify us, life will not be worth living." -- Seneca the Younger, Roman Stoic philosopher | |||
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Ermagherd, 10 Mirrimerter! |
You can buy VFDs on the ‘bay pretty cheap I sell ABB at work, $1400 has ...ahem... a little mark up on it The only way it’s gonna be affordable is DIY I’m afraid I quit school in elementary because of recess.......too many games --Riff Raff-- | |||
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Member |
I had to replace our pump after about 20 years. Did it my self. My pump uses plastic pipe and is down about 30 or 40 feet. Fairly easy to pull and replace. If yours is not to deep it could ne a DIY project. | |||
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Member |
Grundfos makes very good fresh water pumps. We use them on yachts and they hold up a lot better than the home depot/Lowe's stuff. | |||
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Member |
Agreed. The guy is trying to retire off one job. ——————————————— The fool hath said in his heart, There is no God. Psalm 14:1 | |||
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Nullus Anxietas |
I assumed there was a fairly decent markup. Problem is this is not an area in which I have any expertise and I'm disinclined to chance frying an $850 + installation well pump to learn Besides choosing a VFD that will actually do the job and would be reliable, there's the programming of it. No clue wrt appropriate parameters.
Ours is down at 120 feet. As with the above: Something I'm disinclined to mess with. "America is at that awkward stage. It's too late to work within the system,,,, but too early to shoot the bastards." -- Claire Wolfe "If we let things terrify us, life will not be worth living." -- Seneca the Younger, Roman Stoic philosopher | |||
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Shit don't mean shit |
A bit of a tangent here, but I'll throw it out any way. I'm on the Board of our community water system, ~330 homes. We have 4 "deep" wells we draw our water from, 600' - 800' each. We pull a little under 1 million gallons out of the ground monthly. We are considered a "commercial" operation by our local utility. Our pumps may run for hours and hours at a time. For billing purposes, we pay a "peak" rate. When the well pump turns on the current/load "spikes", then declines once the pump comes up to speed. (Not sure if current is the correct term for what spikes, but I think you get the point). We pay about $2,000 per month in electricity usage. To mitigate this, we also use single phase VFD's. With the VFD's we can ramp up the pumps and pay a lower rate so the electricity doesn't spike. I will add that the VFD's need programming. I have not done it personally, but based on what I've heard it's not overly difficult. Our GM did the installs, so if you're moderately technical I bet you can handle the install and programming. I think there are even youtoob videos on the programming aspect. | |||
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Nullus Anxietas |
I'd venture to say I'm more than "moderately" technical, since "tech" is what I've been doing since the era of glow bottles Thanks for the add'l feedback. I'm researching it. "America is at that awkward stage. It's too late to work within the system,,,, but too early to shoot the bastards." -- Claire Wolfe "If we let things terrify us, life will not be worth living." -- Seneca the Younger, Roman Stoic philosopher | |||
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Member |
I've adjusted the programming on the single phase VFD's I've seen. They're not hard to program the ones I have used and use......you adjust the starting and ending speed (cycles) and amount of time you desire to go from starting speed to full ramp up speed (seconds etc. ) 3-phase might be a whole nother matter. | |||
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Member |
While the industrial pricing for a 1hp ABB VFD might be <$500 the plumber is likely not sourcing from OEM industrial supply shops and is paying closer to list price. I don't think $1400 is bad at all, considering he might be making $200 on it. I like Grundfos pumps. Depending on size and features $1400 probably isn't too bad of a price. They make pretty much all of their pumps with integral VFD options now, it's noted by an extra 'e' on the model. For instance CR are their vertical multistage inline, CRe is another model line but is the same pump with a VFD motor on it. I have OEM pricing through them. I can at least look to see how bad of a price you're getting, or potentially sell you the pump when you're ready (depending on several things) since you're somewhat local. At the very least I can get the full performance characteristics and diagrams for it. I don't have a ton of familiarity with home systems and single phase setups, but I design water circulation and heat transfer systems for industrial equipment and customers. Pressure, flow, piping, pumps, all that I can do. I have a dedicated team for controls, so I'm not well versed in getting soft starts and VFDs configured. | |||
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Member |
Motor inrush current is what you're describing to some degree, and what enisigmatic is being troubled with. That's the initial spike to get things moving. The current needed to accelerate the motor shaft further, fight the standing water in the case, push against the static head on the discharge, and create the pressure differential to feed from the suction head is what translates into higher than standard amp draw out of a pump past that initial inrush from the motor itself. This should not exceed nameplate amps for the motor outside of initial <1s rush current, but you'll have a dragged out power curve until the pump is operating at full speed (dragged out further with a VFD/soft start, but at lower amplitude by retarding the motor pole firing frequency). After that, standard centrifugal pumps that are most widely used have an proportional relationship with flow and amps, and inversely so with pressure and amps/flow. The more flow you generate, the more current the motor needs. Closing the discharge and allowing the pump to "deadhead" against a closed valve will show you peak pressure and lowest amp draw, this is commonly done to establish baseline numbers for comparing against test data when evaluating pump/motor health for service. It's also a quick way to smoke the shaft seal in your pump if you're not careful. edit: inrush current stuff; https://sciencing.com/calculat...current-7791777.html | |||
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