Wondering if tees on my suction lines are causing water collision problems

CNJ_EC

0
Jul 1, 2016
37
Somerset NJ
Hi Everyone!

Previous H/O replaced his 2 pumps for a single Pentair IntelliFlo VS 230V/3HP. His original configuration was:

Pump#1 was for the skimmers; 2 - 2" suctions lines; each line had 2 skimmers.
Pump#2 was for the main drain, 1 - 3" suction line; single pair for floor drains on a tee and 48" o/c

When he installed the new pump the suction lines at the pad were reconfigured as follows:

The 3" suction line(main drain) had a 2" reducer installed and 2" pipe extended to a new Jandy Valve
The 2" suction lines(skimmers) were separated from their original tee and Jandy Valves were installed.
See attached pic for current configuration - no pic or documentation on the original configuration.

So I wondering ... is this arrangement is causing water collisions at the tees feeding the pump?

Thanks for your assistance and comments!
 
Welcome to TFP! Good to have you here :)

Yes, there is added turbulence. The added turbulence and smaller intake line would increase friction loss which would require more energy to move the same amount of water.

However, he likely switched to a VS pump so that the pumping could be done at a lower flow rate, which would decrease friction loss by a much greater amount. For example, typically when people use a 2-speed pump at it's lower speed, or a VS pump at a similarly lower speed, they move 1/2 the water per minute and consume 1/4 the energy per minute, thus doubling water moved per kilowatt-hour (as a measure of efficiency).

Yours is a bigger than average pool and I'm sure it needs lots of filtration. I notice 2.5 turnovers in your signature which may not be necessary, so you might be able to cut electrical costs by reducing that. There's a good article here worth taking a look at: Pool School - Determine Pump Run Time
 
Hi Jim,

No ... Pictures were taken while performing a Valve Test and bench-marking pump loss & recovery of PRIME. I plan on rebuilding all 3 Jandy Valves using 3 FlowVis Retro Kits and installing a new 2.5" Glycerin filled Vacuum Gauge on my pump's lower basket drain plug hole.

Normal Suction Line Valve Setting:

Sk 1 - Wide Open
Sk 2 - Wide Open
M/D - 25% Open

Valve Setting during vacuuming:(I alternate between Sk1 & Sk2 each week)

Sk 1 - Wide Open
Sk 2 - Closed
M/D - Closed

Thanks,

TJ
 
Hi,

Thanks for your reply!

When I opened the pool in May the pump was running at 3250RPM. This didn't seem right so I downloaded the 'Installation & User's Guide' from Pentair. After reviewing all the settings it was clear that it was programmed incorrectly. What I found was that the pump was running in Manual Mode and the settings were:

Manual Mode
Spd 1 to Spd 4: 3250 RPM

Schedule Mode was disabled

I spoke to the previous H/O and he told me that the pump was set installed & setup by the pool company he was using. I had the pool company come out to discuss a contract and the settings. When they told me those settings were standard in the industry I pretty much laughed and sent them on their way.

I reprogrammed the pump back to it's default SPD 1- 4 RPM settings of 750, 1500, 2350, 3110. Set Min SPD to 750 RPM and Max SPD to 3200 RPM.

Also, once I have the Values rebuilt and the Vacuum Gauge installed, I'm going to do a visual inspection of the tandem sand filters. Both Pressure gauges are cracked and show a increase of about 8-10 PSI since being backwashed in late May. Each time I've bled the air valves, thick black water shot out(more now then when backwashed) and the pressure jumps back up in about 10 days.

Will order a pair of new Square Rings and 2 new liquid filled Pressure Gauges. Once they arrive, I'll inspect the sand for channeling, sludge, etc. Then decide what to do. If the pool & equipment was taken care of properly I might just do a Chem Cleaning and call it a day. Right now leaning towards removing the sand, washing the tanks down, changing the Tube Air Relief & Strainer Air Relief, adding all new sand or sand with a pea gravel/sand base. Then I'll establish the following Programmed Schedule for the remainder of the season:

SPD 5: 1250 RPM; Start Time: 0905hrs; Stop Time: 1200hrs
SPD 6: 0950 RPM; Start Time: 1205hrs; Stop Time: 2100hrs
SPD 7: 0750 RPM; Start Time: 2105hrs; Stop Time: 0600hrs
SPD 8: 3300 RPM; Start Time: 0605hrs; Stop Time: 0800hrs

I connected my line monitor yesterday so I'll have some good real time load calc's in 30 days. Will post the numbers & a graph sometime in August. From what I can see ... yesterday's peak was 4.9A/1176W.

I read the article ... will provide some feed back once I have the filter situation corrected and my schedule fine tuned. I could get by with a 8-10 hr 1x turnover/pump operation ... but for the time being - will stay with a 2.5 turnover @ 23hr pump operation.

TJ
 
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