Guys & Gals,
This is the report of my pool with undersized piping & long piping run and how it effects the overall water flow.
I am using 2HP SF 1.0 50hz 2,850 RPM Hayward Pump ( A.O Smith motor ).
This is not as powerful as USA model at 60hz & 3,450 RPM pump of same 2HP SF1.0 label.
Bottom line is, the impeller is moving 17.5% slower than a USA model.
Anyhow, even at reduced pumping power, I am already loosing efficiency with all 1.5" PVC pipes, instead of 2".
3 valves are plumbed to the pump suction port. The valves serve :
- Vacuum, pipe length approx 13 feet. Water level to pump's impeller, approx 2 feet.
- Balancing Tank, pipe length approx 13 feet. Water level to pump's impeller, approx 6 feet
- Main Drain, pipe length approx 63 feet. Water level to pump's impeller, approx 2 feet
Normal operation is Balancing Tank + Main Drain valves fullly opened
There are two in-line plunger type check valves. One is at the pipe end of Balancing Tank and the other is about a foot below pump suction pipe. So in normal operation, the pump must overcome these two check valves.
Vacuum gauge and pressure gauge are installed on the holes/thread available on the pump's strainer housing.
So what is being read, is what the pump works against, for suction and for discharge.
PARAMETER 1. Filter condition is not so clean. Check valves installed.
Test 1
All three valves opened.
Vacuum is 8Hg, pressure is 18 psi. Flow is 47.6 GPM
Total Head Loss ( 8 x 1.13 ) + ( 18 x 2.31 ) = 50.6 feet
Test 2
Only Main Drain & Balancing Tank vaves opened. This is the normal operation
Vacuum is 11.5 Hg, pressure is 17psi. Flow is 45 GPM
Total Head loss ( 11.5 x 1.13 ) + ( 17 x 2.31 ) = 52.3 Feet
PARAMETER 2 Filter condition is not so clean. Check valves plunger & spring removed.
Test 3
All three valves opened.
Vacuum is 6.75Hg, pressure is 19.5 psi. Flow is 47.6 GPM. Power consumption 1,568 watts.
Total Head Loss ( 6 x 1.13 ) + ( 19.5 x 2.31 ) = 52.6 feet
Test 4
Only Main Drain & Balancing Tank vaves opened. This is the normal operation
Vacuum is 8 Hg, pressure is 19psi. Flow is 47.6 GPM ( flow meter a bit jumpy & i read the high jump ). Power consm 1,568 watts
Total Head Loss ( 8 x 1.13 ) + ( 19 x 2.31 ) = 52.9 feet
The result of test 1,3 & 4 are confusing, same GPM but different TDH. After removal of check valves plunger + spring and re-starting of pump, I only wait for 2 minuts before doing Test 3 to Test 6. Maybe hidden air bubbles is effecting somehow and a +-10% accuracy flowmeter .
Test 5
Only Balancing Tank valves opened
Vacuum is 11 hg, pressure is 17.5 psi. Flow is 44.9 GPM. Power consumption 1,551 watts
Total Head Loss ( 11 x 1.13 ) + ( 17.5 x 2.31 ) = 52.8 feet
Test 6
Only Main Drain Tank Valves opened
Vacuum is 17hg, pressure is 16 psi. Flow 41 GPM. Power 1540 watts
Persistent air bubble in pump strainer box
Total Head Loss ( 17 x 1.13 ) + ( 16 x 2.31 ) = 56.2 feet
PARAMETER 3
Clogging Test. Filter condition is not so clean. Check valves plunger & spring removed. All three valves opened
Total pump run time between test below and test 1, is about 6 minutes.
Test by closing the pool inlet valve slowly to simulate filter restriction
Test 7 to Test 9
Pressure 22 psi, vacumm drop to 6Hg. Flow 42.3 GPM. TDH 57.58 feet
Pressure 23 psi, vacuum drop to 5.5 Hg. Flow 33 GPM. TDH 59.34
Pressure 24 psi, vacuum drop to 4 Hg. Flow 12 GPM.... bubbles plenty in pump strainer box. TDH 59.96
With so much air bubbles at 24 psi, I doubt both gauges read correctly. At least the flowmeter reads well
Looking at 24 psi pressure and my pump nearly collapse, I think my pump is like a 62-63 feet head maximum.
PARAMETER 4
Clean Filters & new pressure gauges for both sand & cartridge filters
5 hours pump run time before I conducted the test below, hoping hidden air bubbles have gone away.
Test 10
All 3 valves Open, Check valves plunger & spring removed
Pump Suction 8 Hg, Pump Pressure 18 psi, Sand press 10.5 psi, Cartridge press 7 psi, Flow 52.9 GPM ( jumpy )
TDH 50.6 feet
Test 11
ONLY Main Drain and Balancing Tank Valves opened
Pump Suction 9 Hg, Pump Pressure 17.5 psi, Sand press 11 psi, Cartridge press 7 psi, Flow 50.3 GPM ( jumpy )
TDH 50.6 feet
Again, test 10 & 11 results are confusing. Same TDH but different GPM.
NOTE :
The gauges are not a laboratory grade, so I don't know what kind of sensitivity or error. Its sure better than the original ones I had. Now with all new gauges, the reading makes more sense.
The flow gauge I read in Liters Per Minute and I convert to gallons, it is supposed to be only +-10% accurate.
Cost of tools :
3 new pressure gauges ( 2 to replaced original Hayward ones ), 1 Vacuum gauge & 1 flow meter. Damage US$200 only.
Digital volt meter and digital ampere meter, I already got my own, so no extra cost.
Overall I am happy with knowing what's going on with my pool circulation and plumbing variables. At least I am seeing realistic GPM changes when pressure or vacuum reading changes, instead of assumed or theoretical calculated data that I could never really know/verify until today. Even though assuming my flowmeter reading is 10% off, 90% sure is better than guessing.
For those in countries with 50hz electrical supply ( like me ) and using USA made pumps please recheck your pump data sheet.
I been trying to trace USA made pump from Hayward and Pentair website, I can not get their 50hz motor pump curve. All data are of 60hz.
There is a website that can do calculation for you based on Affinity Law ( calculation for pumps ) where it will tell you how much derating from 60Hz to 50Hz unit and many more calculation. Look at the fluid section HERE
Typical GPM derating is like this for my own Hayward as per calculator :
Assuming impeller used are the same :
USA spec is : 2HP SF 1.0 60hz, motor speed is 3,450 RPM ( If this is an approx 70 GPM flow )
50hz country spec is :2HP SF 1.0 50hz, motor speed is 2,850 RPM ( it then becomes 57 GPM flow )
Typical head derating, assuming impeller used are the same.... is a very sad result
USA spec is : 2HP SF 1.0 60hz, motor speed is 3,450 RPM ( ASSSUMING If this is a 75 feet maximum head )
50hz country spec is :2HP SF 1.0 50hz, motor speed is 2,850 RPM ( it then becomes 54.6 feet maximum head )
Looking at my test result which my Hayward Super Pump 2.0HP SF 1.0 ( 50Hz / 2,850 rpm ) pump only pumped out 12 GPM at 59.96 feet of head and very likely will stop pumping at 62 - 63 feet of head, I think the equivalent of this pump in Hayward USA spec is the the 1.1HP SF 1.1 ( Model SP2607X10 Super Pump ) if based of pump head curve. I have always thought a 10% derating was enough, now it seems so wrong.
So, anyone with a pool that has TDH of 50+ feet and is from a 50hz country, please be careful when looking at USA 60hz spec sheet. Get a 50Hz spec sheet....and unfortunately I have surfed for many hours and could not get them. I am saying 50+ feet TDH as caution is because, if a 50 hz pool owner reads 60hz spec sheet and unknowingly choose a pump with 80 feet maximum head, he may get one which is close to useless water flow if pool is 50+ feet TDH. I am waiting for Pentair 50hz pump curve from the dealer. I will share when I get it, as a reference for 50hz pool owners.
If u want to see what the difference is as far as electrical spec of the actual supplied motor for Superflo 60 hz ( USA ) version and 50hz version :
Pentair Superflo
Data from Pentair website
60Hz USA SPEC MOTOR
RPM 3,450
Label HP 1.5
SF 1.65, BHP 2.47
Max Head 71-72 feet
Pump Curve : available on line
Impeller model : available on line
Pentair Superflo
Data from my own motor name plate. This is my back up pump on trolley.
50Hz MOTOR
RPM 2,850
Label HP 1.5
SF 1.10, BHP 1.65
Max Head : Unknown
Pump Curve : Unknown
Impeller model : Unknown
Regards,
SPP
This is the report of my pool with undersized piping & long piping run and how it effects the overall water flow.
I am using 2HP SF 1.0 50hz 2,850 RPM Hayward Pump ( A.O Smith motor ).
This is not as powerful as USA model at 60hz & 3,450 RPM pump of same 2HP SF1.0 label.
Bottom line is, the impeller is moving 17.5% slower than a USA model.
Anyhow, even at reduced pumping power, I am already loosing efficiency with all 1.5" PVC pipes, instead of 2".
3 valves are plumbed to the pump suction port. The valves serve :
- Vacuum, pipe length approx 13 feet. Water level to pump's impeller, approx 2 feet.
- Balancing Tank, pipe length approx 13 feet. Water level to pump's impeller, approx 6 feet
- Main Drain, pipe length approx 63 feet. Water level to pump's impeller, approx 2 feet
Normal operation is Balancing Tank + Main Drain valves fullly opened
There are two in-line plunger type check valves. One is at the pipe end of Balancing Tank and the other is about a foot below pump suction pipe. So in normal operation, the pump must overcome these two check valves.
Vacuum gauge and pressure gauge are installed on the holes/thread available on the pump's strainer housing.
So what is being read, is what the pump works against, for suction and for discharge.
PARAMETER 1. Filter condition is not so clean. Check valves installed.
Test 1
All three valves opened.
Vacuum is 8Hg, pressure is 18 psi. Flow is 47.6 GPM
Total Head Loss ( 8 x 1.13 ) + ( 18 x 2.31 ) = 50.6 feet
Test 2
Only Main Drain & Balancing Tank vaves opened. This is the normal operation
Vacuum is 11.5 Hg, pressure is 17psi. Flow is 45 GPM
Total Head loss ( 11.5 x 1.13 ) + ( 17 x 2.31 ) = 52.3 Feet
PARAMETER 2 Filter condition is not so clean. Check valves plunger & spring removed.
Test 3
All three valves opened.
Vacuum is 6.75Hg, pressure is 19.5 psi. Flow is 47.6 GPM. Power consumption 1,568 watts.
Total Head Loss ( 6 x 1.13 ) + ( 19.5 x 2.31 ) = 52.6 feet
Test 4
Only Main Drain & Balancing Tank vaves opened. This is the normal operation
Vacuum is 8 Hg, pressure is 19psi. Flow is 47.6 GPM ( flow meter a bit jumpy & i read the high jump ). Power consm 1,568 watts
Total Head Loss ( 8 x 1.13 ) + ( 19 x 2.31 ) = 52.9 feet
The result of test 1,3 & 4 are confusing, same GPM but different TDH. After removal of check valves plunger + spring and re-starting of pump, I only wait for 2 minuts before doing Test 3 to Test 6. Maybe hidden air bubbles is effecting somehow and a +-10% accuracy flowmeter .
Test 5
Only Balancing Tank valves opened
Vacuum is 11 hg, pressure is 17.5 psi. Flow is 44.9 GPM. Power consumption 1,551 watts
Total Head Loss ( 11 x 1.13 ) + ( 17.5 x 2.31 ) = 52.8 feet
Test 6
Only Main Drain Tank Valves opened
Vacuum is 17hg, pressure is 16 psi. Flow 41 GPM. Power 1540 watts
Persistent air bubble in pump strainer box
Total Head Loss ( 17 x 1.13 ) + ( 16 x 2.31 ) = 56.2 feet
PARAMETER 3
Clogging Test. Filter condition is not so clean. Check valves plunger & spring removed. All three valves opened
Total pump run time between test below and test 1, is about 6 minutes.
Test by closing the pool inlet valve slowly to simulate filter restriction
Test 7 to Test 9
Pressure 22 psi, vacumm drop to 6Hg. Flow 42.3 GPM. TDH 57.58 feet
Pressure 23 psi, vacuum drop to 5.5 Hg. Flow 33 GPM. TDH 59.34
Pressure 24 psi, vacuum drop to 4 Hg. Flow 12 GPM.... bubbles plenty in pump strainer box. TDH 59.96
With so much air bubbles at 24 psi, I doubt both gauges read correctly. At least the flowmeter reads well
Looking at 24 psi pressure and my pump nearly collapse, I think my pump is like a 62-63 feet head maximum.
PARAMETER 4
Clean Filters & new pressure gauges for both sand & cartridge filters
5 hours pump run time before I conducted the test below, hoping hidden air bubbles have gone away.
Test 10
All 3 valves Open, Check valves plunger & spring removed
Pump Suction 8 Hg, Pump Pressure 18 psi, Sand press 10.5 psi, Cartridge press 7 psi, Flow 52.9 GPM ( jumpy )
TDH 50.6 feet
Test 11
ONLY Main Drain and Balancing Tank Valves opened
Pump Suction 9 Hg, Pump Pressure 17.5 psi, Sand press 11 psi, Cartridge press 7 psi, Flow 50.3 GPM ( jumpy )
TDH 50.6 feet
Again, test 10 & 11 results are confusing. Same TDH but different GPM.
NOTE :
The gauges are not a laboratory grade, so I don't know what kind of sensitivity or error. Its sure better than the original ones I had. Now with all new gauges, the reading makes more sense.
The flow gauge I read in Liters Per Minute and I convert to gallons, it is supposed to be only +-10% accurate.
Cost of tools :
3 new pressure gauges ( 2 to replaced original Hayward ones ), 1 Vacuum gauge & 1 flow meter. Damage US$200 only.
Digital volt meter and digital ampere meter, I already got my own, so no extra cost.
Overall I am happy with knowing what's going on with my pool circulation and plumbing variables. At least I am seeing realistic GPM changes when pressure or vacuum reading changes, instead of assumed or theoretical calculated data that I could never really know/verify until today. Even though assuming my flowmeter reading is 10% off, 90% sure is better than guessing.
For those in countries with 50hz electrical supply ( like me ) and using USA made pumps please recheck your pump data sheet.
I been trying to trace USA made pump from Hayward and Pentair website, I can not get their 50hz motor pump curve. All data are of 60hz.
There is a website that can do calculation for you based on Affinity Law ( calculation for pumps ) where it will tell you how much derating from 60Hz to 50Hz unit and many more calculation. Look at the fluid section HERE
Typical GPM derating is like this for my own Hayward as per calculator :
Assuming impeller used are the same :
USA spec is : 2HP SF 1.0 60hz, motor speed is 3,450 RPM ( If this is an approx 70 GPM flow )
50hz country spec is :2HP SF 1.0 50hz, motor speed is 2,850 RPM ( it then becomes 57 GPM flow )
Typical head derating, assuming impeller used are the same.... is a very sad result
USA spec is : 2HP SF 1.0 60hz, motor speed is 3,450 RPM ( ASSSUMING If this is a 75 feet maximum head )
50hz country spec is :2HP SF 1.0 50hz, motor speed is 2,850 RPM ( it then becomes 54.6 feet maximum head )
Looking at my test result which my Hayward Super Pump 2.0HP SF 1.0 ( 50Hz / 2,850 rpm ) pump only pumped out 12 GPM at 59.96 feet of head and very likely will stop pumping at 62 - 63 feet of head, I think the equivalent of this pump in Hayward USA spec is the the 1.1HP SF 1.1 ( Model SP2607X10 Super Pump ) if based of pump head curve. I have always thought a 10% derating was enough, now it seems so wrong.
So, anyone with a pool that has TDH of 50+ feet and is from a 50hz country, please be careful when looking at USA 60hz spec sheet. Get a 50Hz spec sheet....and unfortunately I have surfed for many hours and could not get them. I am saying 50+ feet TDH as caution is because, if a 50 hz pool owner reads 60hz spec sheet and unknowingly choose a pump with 80 feet maximum head, he may get one which is close to useless water flow if pool is 50+ feet TDH. I am waiting for Pentair 50hz pump curve from the dealer. I will share when I get it, as a reference for 50hz pool owners.
If u want to see what the difference is as far as electrical spec of the actual supplied motor for Superflo 60 hz ( USA ) version and 50hz version :
Pentair Superflo
Data from Pentair website
60Hz USA SPEC MOTOR
RPM 3,450
Label HP 1.5
SF 1.65, BHP 2.47
Max Head 71-72 feet
Pump Curve : available on line
Impeller model : available on line
Pentair Superflo
Data from my own motor name plate. This is my back up pump on trolley.
50Hz MOTOR
RPM 2,850
Label HP 1.5
SF 1.10, BHP 1.65
Max Head : Unknown
Pump Curve : Unknown
Impeller model : Unknown
Regards,
SPP