Upgrade recommendations for replacing 14" Intex sand filter combo?

I think I totally don't trust the engineering and efficiency data supplied . . . well, by anybody.

Years ago, I had made the acquaintance of the then PacFab's chief engineer, and through him, several junior working engineers. Occasionally, I could call and get the 'back-story'. Even then, before it became Pentair, it was a marketing driven company. And, the gap between what was supposed to be true, and what was true was significant.

Hayward has always been opaque, at least to me. But the mere fact that the Hayward chlorinator -- this beast:
http://www.poolcenter.com/images/PC_...15/E6015_f.jpg
is still sold, is evidence that Hayward can't be trusted.

That chlorinator has not worked right since it was first designed and sold, over 35 years ago. The main port is a HORRIBLE flow restriction, and is so small it literally will not pass a US quarter. And the feed rate control NEVER works right, even out of the box. They know that. But they still sell it.

So yes, I'd love to have other data.

So I've been looking at PVC thread sealant. I have lots of experience with threaded metal pipe & fittings, and glued PVC, but not so much threaded PVC. I was thinking I'd just use teflon tape but Lasco says don't. There seems to a bunch of conflicting advice on the ww-interweb. Can you believe that? About the only thing that most agree on is don't use petroleum based products because they can attack PVC. Any experienced suggestions on what to use? Teflon or this - https://www.amazon.com/Plasto-Joint-...ct_top?ie=UTF8 - ?

Also, since I'm kinda worried about overloading a plug-in Kill-a-Watt meter, I'm thinking this - https://www.amazon.com/gp/product/B0...AKNUUM9N&psc=1 - is the ticket. 1% claimed accuracy.

The meter looks OK. I'd want to compare it with something else once it was in operation.

I've never used Plasti-Joint. It may be great. However it looks a bit small to be using on 1.5" and 2" threads. Here's what I used the last few years:

Rectorseal 31551 1/2 Pint Brush Top Tru-Blu Pipe Thread Sealant

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Originally Posted by PoolDoc

The meter looks OK. I'd want to compare it with something else once it was in operation.

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Even if the reading is not accurately calibrated, it should give an accurate comparison between the 2 pumps - I'd think.

And thanks for the tip on the Rectorseal.

The last of my goodies should come in Saturday or Monday. I suppose I'll start a new thread documenting the conversion from Intex proprietary to standard pipe. I think I'm going to focus on the generic bits - like the timer, GFCI, and pool wall fittings.

Thanks!

I got the ammeter assembled today. My Intex SF70110 pump/filter pulls 4.2 A @117 V. with the filter pressure about "middle ways" between "just backwashed" and "needs backwashed now". The manual and motor tag say 4.8 A. The pump pulls 3.8 A deadheaded.

Just for grins, I checked a cheapo heat gun that's rated at 1500 W 120 V. That converts to 12.5 A. It actually pulled 10.8 A 117 V. or about 1250 W. Heating devices are routinely rated at higher than actual wattage to make them "seem" more powerful. So - - - I feel like the meter is reasonably accurate.

Excellent experimentation. 4.2 x 117 => maybe 400 watts? Does your meter show true power, or just volt-amperes? Does it show power factor?

Anyhow, 0.4kw x 24 x 30 = 288 kwh/month. At $0.14/kwh that's $40/month. I think that's more than most folks realize.

By the way, you may be able to measure the actual flow gpm to within 10% with a 5 gallon bucket, a heavy duty garbage bag, a household scale, and the timer on your phone. It depends on whether you can reliably seal the throat of the bag, so that the pool inflow is capture by the bag. You'd also need a decent twist tie (or a nylon wire strap) to seal the bag . . . and the bucket so you can lift the bag without busting it.

This is a pic of the meter plugged into a space heater rated at 1500 watts. The limited instructions that came with it say "Voltage, current, active power, energy".

https://i.imgur.com/OofhT5h.jpgg

And I just happen to be storing some plastic 15 gallon beer fermenters for an associate. Do I really need a trash bag? I presume I run the pump into a container for 15 seconds, then weigh the water, multiply by 4 and divide by 8.34 to get the GPM?

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Originally Posted by Pappy

Do I really need a trash bag? I presume I run the pump into a container for 15 seconds, then weigh the water, multiply by 4 and divide by 8.34 to get the GPM?

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I was assuming you had a submerged inlet. If you are able to plug the pool and disconnect the pump effluent, so you can discharge directly into your tank, you can get the measurement as you say.

Regarding the meter, with resistance elements VxA = true watts, but with inductive elements (motor windings), true watts are usually less than V x A due to power factor.

I am able to plug the pool and disconnect the hose. As for the meter, if there is power factor correction feature, I'm not aware of how to access or activate it.

Just looked; the meter info on Amazon claims it ONLY reads true power, not VA.

However, if it is reading true power, the reading for watts should be lower than the V x A number.

I had time to check the Intex flow rate this morning. It pumped 55 lbs of water in 15 seconds. That's about 220 lbs/minute at 8.34 lbs/gal. I figure that comes to roughly 26 GPM.

This is what the meter reading was during the test.
https://i.imgur.com/QzMfSIU.jpg

OK. Unless that pump has a capacitor, the calculator is showing VA, and not true power. PF for fractional inductives seems to range from 0.75 to 0.9.

And, your 2150 GPH rated pump pumped an actual 1560 GPH, or about 75% of it's rating.

This is one reason it is so hard to optimize residential pump + filter sets: the engineering data is missing or wrong!

Still . . . this is all very interesting.

Quote:

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Originally Posted by PoolDoc

your 2150 GPH rated pump pumped an actual 1560 GPH, or about 75% of it's rating.

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True. I kinda wonder what it would flow when freshly backwashed. I also believe it cannot be very efficient, because when the filter basket gets cleaned, and is full of air, the pump won't prime. The air bleed valve at the top of the filter basket has to be opened to release the trapped air.

As for the meter, 116V x 4.2A = 487.2W. The meter is reading 482.7. Is that difference due to significant figure rounding, or true power?

AND, the plumbing got done for the new Pentair/Hayward system. I have to get more wire, we decided to move the pump/filter to a different location, farther from the power source, and I need wiring that is about 4' longer.

If the difference between VxA and W were true power you ought to be seeing a gap of at least 40 watts. That would STILL be a PF > 0.9, which would be exceptionally high, without capacitor correction.

As far as additional wiring, if you use twisted AND soldered connections, you can simply splice a piece on. I would not used merely twisted and nutted connections for such a splice. (I assume you know to use rosin flux and not acid flux?).

I have discovered it is less expensive to buy an extension cord of appropriate gauge from Amazon and cut the ends off, than to buy cut-to-lenght wire so, I just have an extra heavy duty extension cord now. And, yes, about the flux.

:)