old pump new motor - figuring out the specs

[Diver]

I have an old SP2607X10 superpump. I replaced the original 1 speed motor with new 2 speed STS1072RV1 one and now I would like to figure out the flow rates and wattage for the new configuration.

I’m getting a vacuum gauge so using filter pressure and vacuum readings I will be able to figure total dynamic head. I assume that the head curve for high speed will be the same as old SP2607X10 superpump had – the impeller is the same, the pump wet end is the same and the motor will spin it at the same 3450 rpm provided there is no slippage. Since the new motor is 1.125 SFHP and the old one was 1.1, there shouldn’t be any. Using the old superpump head curve, I could find the flow rate by intersecting total head and the curve. So far so good.

Now for the low speed things are a bit more difficult. Superpump has a 2 speed version - SP2607X102S. The motor is 1 SFHP (not sure about low speed), which is close enough, but the pipe size is 2” instead of 1.5”. I would think it would make an impact on the head curve. On other hand, 1.5SFHP version has a low speed curve that is not that different from 1 SFPH (see the pic attached)! So maybe the head curve for SP2607X102S would be close enough for my case?

Now for the wattage. My assumption is that using numbers referenced above it’s not really possible to get the running wattage for the new pump on hi/low speeds, is it? If head curve is determined by wet end only then it doesn’t really matter if water is moved around by energy efficient motor or not, the flow rate will be the same. So is there a good way to figure the wattage out? Besides amp clamp and watching electric meter spin?

Thanks!!

 

[Bama Rambler]

The flow rate on high is going to pretty much match your old pump and the flow rate on low will be about half your old flow.

Once you get the suction and discharge pressures you cen figure the flow rate and get a guestimate of the wattage. But to get an accurate number for the wattage you'll need to actually measure the voltage and current when it's running normally.

 

[Diver]

Once you get the suction and discharge pressures you cen figure the flow rate and get a guestimate of the wattage

how do i guestimate the wattage? is there a formula?

 

[Bama Rambler]

Wattage is volts x amps so if you you have a pump that's 230 volts and it draws 5 amps, and it's running on it's curve then you can figure that it'll be using about 1150 watts. Like I said it's only a guestimate because without actually measuring the variables it's just a guess.

 

[Diver]

Wattage is volts x amps so if you you have a pump that's 230 volts and it draws 5 amps, and it's running on it's curve then you can figure that it'll be using about 1150 watts. Like I said it's only a guestimate because without actually measuring the variables it's just a guess.

Bama, thanks for your reply. If I knew the amperage, then there wouldn't be any problem figuring out the wattage. I was wondering if there are other ways:

So is there a good way to figure the wattage out? Besides amp clamp and watching electric meter spin?

 

[mas985]

The problem with using amps on low speed is that the power factor is usually really low so power factor would need to be measured which is not easy to do. But as a general rule of thumb, on low speed, the wattage will be between 20%-25% of high speed wattage.

But give me your head calcs and I can give you the theoretical power usage based off of the CEC measurements.

 

[Diver]

But give me your head calcs and I can give you the theoretical power usage based off of the CEC measurements.

Mark, I'll get the numbers when I have the pump up and running. Right now it's all assembled and dry tested.

Should i post the #s to this thread? it will be at least another month before i open the pool.

 

[mas985]

Posting here would be fine. Just give me both the filter pressure and suction in-hg at full speed.

 

[Diver]

will do

 

[Diver]

Mark,

i finally open the pool, had everything started and got the numbers. with filter freshly coated, my vacuum gauge at the bottom of the pump reads 6.5", my filter pressure is 8.5 psi. Reading at the low speed are both zero. Not relevant, but interesting, on recirculate with MD only, vacuum reading is 23" on high and 5.5" on low.

i calculated my total head to be 30 which gives me about 72 GPM of flow rate at high speed. my return head is 3 times the suction head: 22.635 and 7.345 respectively. i thought suction would be higher since i have 2 1.5" suction pipes and 3 1.5" return pipes.

i also timed the electric meter so i will have some numbers to compare to yours wattage wise!

thanks for your help!

 

[Diver]

derived from electric meter: high speed - 1260W, low speed - 306W

 

[mas985]

When calculating the operating point, I also like take into account the backwash valve before the pressure gauge so what size backwash valve do yo have (2" or 1.5")?

Here are the numbers assuming a 2" valve:

[tr:2l5m3ofp][td:2l5m3ofp] Operating Point [/td:2l5m3ofp][td:2l5m3ofp] [center:2l5m3ofp][/center:2l5m3ofp] [/td:2l5m3ofp][td:2l5m3ofp] [center:2l5m3ofp][/center:2l5m3ofp] [/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Pump Speed (RPM) [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]3450[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]1725[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Flow Rate (GPM) [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]63[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]32[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Total Head Loss (ft) [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]33[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]8[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Suction Head Loss (ft) [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]7.3[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]1.8[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Pre-Gauge Head Loss (ft) [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]3.3[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]0.8[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Return Head Loss (ft) [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]22.6[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]5.7[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Total Plumbing Curve [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]0.0083[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]0.0083[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp][/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp][/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Energy Use (watts) [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]1212[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]282[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][tr:2l5m3ofp][td:2l5m3ofp] Energy Factor (Gallons per Watt-Hr) [/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]3.13[/center:2l5m3ofp][/td:2l5m3ofp][td:2l5m3ofp][center:2l5m3ofp]6.73[/center:2l5m3ofp][/td:2l5m3ofp][/tr:2l5m3ofp][/table:2l5m3ofp]

 

[Diver]

When calculating the operating point, I also like take into account the backwash valve before the pressure gauge so what size backwash valve do yo have (2" or 1.5")?

Mark, how do i determine that? i have Hayward Pro-Grid DE4820 filter, so i assume multiport valve is the one that usually comes with it.

 

[mas985]

If you have 1.5" pipe going into the backwash valve without any resizing fittings, it is probably 1.5", same for 2" pipe. Also, there should be a model # for the valve.

 

[Diver]

Mark,

I have a SP710XR50 multiport valve, which seems to be 1.5". For some reason i got confused by the term "backwashing valve", but now I understand what you mean. The valve is rated at 75 GPM.

Thanks for all your help, you're a very valuable resource on this forum!

 

[mas985]

That changes things slightly:

[tr:3o6xdbew][td:3o6xdbew] Operating Point [/td:3o6xdbew][td:3o6xdbew] [center:3o6xdbew][/center:3o6xdbew] [/td:3o6xdbew][td:3o6xdbew] [center:3o6xdbew][/center:3o6xdbew] [/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Pump Speed (RPM) [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]3450[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]1725[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Flow Rate (GPM) [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]58[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]29[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Total Head Loss (ft) [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]38[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]9[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Suction Head Loss (ft) [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]7.3[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]1.8[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Pre-Gauge Head Loss (ft) [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]7.9[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]2.0[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Return Head Loss (ft) [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]22.6[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]5.7[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Total Plumbing Curve [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]0.0112[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]0.0112[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew][/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew][/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Energy Use (watts) [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]1212[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]282[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][tr:3o6xdbew][td:3o6xdbew] Energy Factor (Gallons per Watt-Hr) [/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]2.87[/center:3o6xdbew][/td:3o6xdbew][td:3o6xdbew][center:3o6xdbew]6.17[/center:3o6xdbew][/td:3o6xdbew][/tr:3o6xdbew][/table:3o6xdbew]

 

[Diver]

Mark, thanks for the info!

 

[Diver]

Mark,

I've been re-reading your hydraulics 101 and going thru this thread again. You specified "Pre-Gauge Head Loss (ft)" as 7.9ft for 1.5" multiport valve and 3.3ft for 2" valve for my specific situation.

Are these numbers based on the info from the filter type and efficiency table from this thread of yours?

In the table the loss for hayward progrid DE filter with 2" multiport is 3.8 and for 1.5" multiport it is 6.0. It's all for 30 ft of total plumbing head. My total head loss is 29.9ft, so it seems that the numbers should match almost perfectly.

But since they are different 7.9/3.3 vs 6.0/3.8, I'm wondering if there is something else that is taken into account when pre-gauge head loss is calculated? Especially since the difference is in one direction for 2" and in another direction for 1.5" valve.

Thanks!

 

[mas985]

n the table the loss for hayward progrid DE filter with 2" multiport is 3.8 and for 1.5" multiport it is 6.0. It's all for 30 ft of total plumbing head. My total head loss is 29.9ft, so it seems that the numbers should match almost perfectly.

Not quite, you are using the 30 GPM numbers but your flow rate is closer to 60 GPM so you should be using the numbers in the next column to the right.

The pre-gauge head loss takes into account all the plumbing from pump to filter gauge so it usually will have a bit more head loss than just the multiport. Plus, the way I model the head loss for the multiport is that I apply half the head loss before the gauge and half after the gauge. All of the filter head loss I apply after the gauge although there is a little bit before gauge. When you use the filter pressure for return head loss, you need to keep mind that it contains 1/2 the multiple port valve and all of the filter losses. The only thing that is not included in the filter pressure is the pre-gauge losses which is why I separate that out.

 

[Diver]

Mark, I actually misread the table. I thought the columns of the table were the head, not the flow, so i matched my 30ft of total head with a 30 gpm flow! sorry, my bad!

with that in mind, i'm even more confused with the number 24 ft from the table (intersection of 60 GPM and Hayward ProGrid DE with 1.5" rows)

i have 22.6 return head, 7.3 suction head and 7.9 pre-gauge loss, which adds up to 38 total head loss. so it sounds that 24ft is part of the total loss.

you said:

When you use the filter pressure for return head loss, you need to keep mind that it contains 1/2 the multiple port valve and all of the filter losses.

my return loss is 22.6. filter + multiport loss is 24ft (from the table). half of it is 12ft. which makes the loss of my return plumbing 10.6ft (3 x 1.5" lines). is this correct so far?

now i have suction loss of 7.3, remaining half of the (filter + multiport) loss (12ft) and 7.9 pre-gauge loss number that you came up with. i'm trying to figure out how exactly you arrived at 7.3, but i don't seem to be able to get there

if you have a moment, can you explain a bit? also, what is Total Plumbing Curve number that you provided in the tables above?

thank you!