Time for a new pump

[Rich Purdum]

Mark,

I suppose the main factor in going with the higher HP was a greater "comfort level" that I wouldn't be under-sizing. Also, I am unsure of the real implications of the SF number. I read (somewhere) this would allow handling of higher loads for short periods. If it is going to take a continuous 1 HP force then the 1 HP WFE-4 could more easily handle the load. I agree it seems a "bit oversized" but for running the suction side cleaner I also read (somewhere) that this type of cleaner required more HP.

Using the "equivalent length" worksheet from the Engineering Toolbox, the numbers came out with 23 FT of loss. Since the Hayward is only 1-1/2 in/out, it's probably the bottleneck in the current setup. When the pool was rebuilt everything went to 2" except the line for the Kreepy (1-1/2) and the old main drain (1-1/2 copper). The pressure gauge on my filter has never gone above about 4 psi so I'm assuming there is lots of room for increased discharge side flow rates and hopefully shorter run times. Also to get the Kreepy to move at a decent clip I have to set the Jandy so the skimmer is barely swirling, so to say the 1HP Hayward is doing the job is I suppose a bit of a stretch (although the pool stays very clean).

I'm probably at the stage where I'm just confusing myself even more by looking at more data. If you think the WFE-4 is too much pump for my setup let me know. The WFE-3 is in stock and I could get started on the install today without worrying about the old Hayward disintegrating.

Rich

 

[JasonLion]

The WFE-3 pump is fairly powerful, noticeably more pump than you have now. It is just fine for most pools as long as you don't have a spa or any water features. The WFE-3 can usually do better than 60 GPM, which is more than three turnovers a day for your pool. Many people make the mistake of assuming that a larger pump is better, but beyond a certain size all a larger pump does is use more electricity and reduce the filtering ability of the filter.

The Hayward SP2807X10 spec says 51 GPM at 40 ft of head, while the Pentair WFE-3 chart shows 80 GPM at 40 ft of head. The WFE-4 would be 100 GPM at 40 ft of head, which is very likely to be more than your filter is designed to handle.

 

[mas985]

Ditto to what Jason said. Also, you are underestimating the equivalent length of your plumbing by a lot. However, you should be no worse than Curve-C with 2" plumbing so the WFE-3 should produce at least 80 GPM @ 51' of head while your old pump was probably around 64 GPM @ 33' of head so the WFE-3 is much more powerful than your old pump. Even a WFE-2 is more powerful at 69 GPM @ 40' of head. So you could even go with a WFE-2. Remember that your current pump is an uprated 1 HP which is the same as a 3/4 HP full rated pump but the WFE series is more powerful pump so a WFE-2 is fine.

 

[polyvue]

The pressure gauge on my filter has never gone above about 4 psi so I'm assuming there is lots of room for increased discharge side flow rates and hopefully shorter run times.

My pool's volume is little more than half of yours and the daily run time is brief (3 hrs summer, 1.5 hrs winter) for 1 turnover; this, accomplished with a med-high head pump similar to the one you're considering, 2 inch all 'round, a fat filter, not many fittings, short distance from pad to pool, parallel home runs and a spa spillover. The 2" OD pipe is the limitation. My pump's rated performance (1.85 BHP 110 GPM @ 40 FT) is a race horse. While I obviously take a certain amount of pride in the equipment sizing and short run times, I think I bought too much pump. But every system is different; you have good arguments (suction cleaner etc.) and one's comfort level is surely more important than potential future savings on monthly electric bills. That's what I keep telling myself, anyway...

If the cartridge filter listed in your signature is still pertinent I can't see how either pump will present a problem. The WFE3's total HP is about 1.25 vs. 1.65 for the WFE4, right?

So, those are my opinions - however unbacked by expertise! Hopefully this post will serve as a pleasant momentary diversion from your conservation with the real experts.

 

[Rich Purdum]

OK guys,

The WFE-3 sounds good. When the pool was rebuilt the company "super sized" the filter...the CC520 can handle 150 GPM according to mfg specs. This was based on the number of large trees nearby.

I got the figures for the fittings from Engineering Toolbox site as well as their spreadsheet and I have photographs of the new plumbing before everything was filled in so the fitting counts are correct. I may have stepped on one of their calcs. The equipment pad is fairly close to the pool. Total intake is 24' of 1-1/2 copper, 19 ' of 2" PVC and 43' of 1-1/2 PVC. This is to the Jandy valve. Discharge is 60' of 2" PVC from filter to the most distant return outlet. The actual return outlets are 3 1" directional swivel fittings which complicates the calcs I am sure.

I know the smaller pump will do the job, just didn't want to leave anything on the table.

Going to head out to pick up everything and get started in the morning.

Thanks again to all for all the advice.

Rich

 

[Rich Purdum]

Whisperflo installed but...

Fired up the new pump this afternoon, bled all the air out of the filter, re-balanced the Jandy so the Kreepy moved correctly and all is fine except my Whisperflo is not "whispering" as I expected. The motor itself seems very quiet but there is a semi-soft rattle-like sound which seems to come from the pump. The pressure gauge on the filter now reads around 6 or 7...with the Hayward it barely reached 2. There water level in the pump strainer is right at the top when the pump is operating so I don't think it is being starved on the intake side. Also, when everything was down I cleaned the filter cartridges. (In re-plumbing the pad I was able to eliminate 1 45 and 1 90 degree elbow.)

As it stands, the new pump is only marginally quieter than the old one. The outfit I bought the pump from will send someone out in the next day or so to take a listen.

Until then, does anyone have any idea what might be going on or were my expectations unrealistic?

 

[mas985]

With that pump and only 6 PSI pressure, either the suction head is unusually large or the return head unusually low. Both could cause some pump noise. On 2 1/2" suction and 2" return pipe, I would expect a filter pressure of around 14 PSI with that pump.

Please describe your plumbing setup:

Suction Pipe: Number of runs, length pool to pad and diameter
Return Pipe: Number of runs, length pool to pad and diameter

 

[Rich Purdum]

Plumbing setup

Mark

Suction side (2 runs):

Waterway Renegade Skimmer two port 2"
Port 1: 2" PVC to Jandy at pad - 19 feet - 3 90 degree elbows
Port 2: 1-1/2" copper from main drain - 24 feet 4 90 degree elbows (not sure this is relevant since Port 1 is only Suction from Skimmer)

Kreepy Krawley suction side cleaner
1-1/2" PVC to Jandy at pad - 43 feet - 4 90 degree elbows

Jandy outlet to pump intake (don't think this matters other than it's 2")
2" PVC - about 18"

Discharge side (one run):

Pump discharge to filter - 2" PVC - about 2 feet - 1 90 and 1 45
Filter to return outlets (there are 3) - 2" PVC - 60 feet - 3 90 elbows and two tees - all returns end it 1" eyeball fittings

Rich

 

[mas985]

If you are saying there are three separate lines on your return side, each to an eyeball, then that is what is causing the noise. I get close to 6 PSI with that setup and 91 GPM @ 28' of head.

Normally, low head loss is a good thing but with such low head loss, the operating point is close to runnout for that pump. With such high flow rates, you are probably hearing water noise in the plumbing and pump housing. There are a couple problems with such high flow rates. First, is that you are considerably over the best efficiency point which is around 65 GPM. This adds stress to the impeller shaft and could reduce the life of the pump bearings but is not so bad on a 3/4 HP pump. Second, the operating point can also put the pump at high risk of cavitation. Do you see any bubbles in the pump basket?

If you can control the flow rate to each of the three returns, then try reducing the flow rate until the noise subsides. This should be around 14 PSI. Your flow rate will be around 76 GPM but it should be much quieter.

 

[Rich Purdum]

Flow rate

Mark

To clarify, there is a single 2" PVC return line which runs along the long side of my rectangular pool. At two points in this run there is a 2 x 2 x 1-1/2 Tee with the 1-1/2 leg going through the pool wall and terminating in a 1" eyeball. At the far end of the return (at the shallow end) there is a 90 degree elbow reduced down to 1 1/2 with a final 1" eyeball. I guess I didn't step on the equivalent length worksheet from the Toolbox after all. See my post earlier in this thread..I got 23 feet .

My perception is that there is significantly more surface movement at the shallow end. Since the skimmer is in the opposite corner of the deep end I believe the remodel folks were trying to get surface movement toward the skimmer. I'm going to try redirect them a bit as there is so much flow that the eddy is swirling back away from the direction of the skimmer.

I looked for bubbles in the pump basket and if they were there they were very small. There was some debris flying around in the turbulence and it was difficult to be sure. I'll clean it out and take another look this morning.

At present, I have no way of regulating return flow. However, there is an easy way to cut into the single return line as it leaves the filter. I suppose a two way Jandy would be the "regulator" of choice?

Aren't we glad I didn't go for the WFE-4!!! :-D

Rich

 

[JasonLion]

When returns are chained along a single pipe it often helps to use a slightly smaller size return eyeball on the return that is closer to the pump. If you replaced the nearer one with a 3/4" that would tend to balance out the flow between the two returns better.

 

[mas985]

A single return line changes things. With the new assumption, I would expect a filter pressure of about 10 PSI and an operating point of 84 GPM @ 36' of head. Still low but not as low as what you are seeing which makes me think there is something going on in the suction side as well. Do you have both the main drain and skimmer lines fully open and do they run the full length of the pool to pad? Can you get a pressure reading with only one or the other open?

 

[Rich Purdum]

Answers and photos

Jason, unfortunately I believe the eyeballs are the slip type and thus cemented into the line.

Mark,

The main drain is plumbed through the skimmer (see this link) and there is a single 2" suction side line going from there to the Jandy at the pad. Earlier I tried moving the Jandy 3 port all the way both ways, i.e. shut off the 2" line from the skimmer and shut off the 1-1/2" line from the cleaner. MAJOR cavitation with the skimmer off...the pump basket chamber literally turned cloudy with bubbles. Very slight increase in noise with the cleaner off. I get the best performance on the cleaner with the Jandy set about 1/3 of the way from "Off" on the skimmer. The pad is about 11' from the deep end of the pool so a short run.

Unfortunately I don't have pressure gauges other than on the filter.

Here are some shots:

The Pad

The Skimmer end

The Return side

From the shallow end (the pad area is behind the fence and under the walkway)

If more pics will help just let me know.

Rich

 

[mas985]

Ok, I think we are getting closer. So the 6 PSI, was that with the skimmer partially off? What is the pressure with the skimmer and main drain fully on?

 

[Rich Purdum]

Mark

First the skimmer/main drain should (I think) be considered as one. The main drain is plumbed into the chamber of the skimmer and there is another 2" line going from there to one port on the 3 port Jandy valve. The other port on the Jandy is suction side for the cleaner. So I can only balance between the skimmer/main drain line and the cleaner.

If I put the Jandy in the middle (which I assumes means both ports are wide open), there is a slight decrease in noise. I disconnected the Kreepy from it's hose and submerged the hose...no noticeable change...so that's the best I can do on the supply side. I then reached down and blocked the first eyeball outlet and there was a very noticeable drop in noise.

I performed a closer inspection of the pump strainer cavity and there is (as best as I can tell) a faint trace of bubbles with the Jandy in the center (wide open) position.

The pressure on the filter gauge is between 6.5 and 7 once the pump is running. There is a brief spike to around 13-14 on startup and then it settles down. As I swing the Jandy to turn off the skimmer, there is a fairly quick drop (down to about 3 or less) as the pump goes into cavitation.

For grins...

Here is pump basket with pump running and Jandy in the center position....

Here is same with the Jandy approaching the Off position on the skimmer...when completely off it looks like milk...

Based on my experiment with the eyeball outlet, seems like a balancing valve between the filter and the outlets might be in order?

Rich

 

[mas985]

It sounds like the pump is being starved of water. You might want to double check the line going from the valve to the skimmer to make sure there is no blockage anywhere. That line seems to have a bit more head loss than what I would have predicted. If that is clear, then the only thing you can do is add head loss to the return side via a valve. The more head loss you have on the return side vs the suction side, the lower the pump and water noise will be. However, it is also less efficient but there are always trade-offs.

 

[Rich Purdum]

Trade-offs

Mark,

Yeah, that old trade-off thing. I can't see how there can be a blockage unless it's at the Jandy, which moves freely. IMHO, the new pump took the pool past it's design point (if there ever was one). Perhaps if they had plumbed the line from the skimmer to the Jandy with 2-1/2" I would not be having this issue.

Oh well...I'm still better off than with the Hayward. I'll post the results after adding the balancing valve on the return line.

Rich

 

[JasonLion]

Some kind of partial blockage somewhere in the suction pipe seem likely. You could try using a drain king to push water back from the pump towards the skimmer and see if anything comes out.

 

[Rich Purdum]

Blockage

Jason,

Unfortunately my smaller drain king blew out last year and I have not replaced it. Will pick up on tomorrow and give it a shot.

I did not realize that the eyeball fixtures would unscrew until I was at the local pool place today. They are all 1" units.

I covered up the first one in the line while someone observed the filter and the pressure went from 6+ to just under 10 (and of course the noise dropped off substantially as before). At that rate if I'm looking for around 14-15 at the filter I'd have to block part of an additional outlet which I don't think is advisable.

Sorry if this thread has started to meander. I thought I was done yesterday.

Rich

 

[Rich Purdum]

No blockage

Drain king inserted into pump intake did not result in any material showing up in the skimmer chamber. As an experiment I inserted a large fresh green leaf into the 2" suction line in the skimmer and it showed up just fine in the pump strainer. I realize this is not conclusive.

I'm back to adding head on the discharge side as the only course of action left (short of getting a smaller pump). My plan is to insert a Jandy 2 port Neverlube just after the return line leaves the filter. The only downside is that if someone closed it while the pump was running it would probably pop the top off the filter. I could always put a permanent warning tag on it. If there other courses of action, please let me know. I plan to order the valve tomorrow.