Two 5 hp pump

MaxHeadRoom

Joined Jul 18, 2013
30,665
If you can find one for 1ph you may be lucky with a pump application, but generally 1ph VFD's do not work that well, they have a tendency to drop out of run when loaded and/or at low RPM.
Hence the popularity of 3ph VFD's and motors, whether 1ph or 3ph supply.
Max.
 

LesJones

Joined Jan 8, 2017
4,511
Using a single phase input to 3 phase output VFD and 3 phase motors may be a solution to your problem. They could be programmed to ramp up the speed which would reduce the starting current.

Les.
 

Reloadron

Joined Jan 15, 2015
7,891
The starting current of a single phase motor will be many times the full load current. I think the starting current of the motors is likely to cause a problem.

Les.
I also thought about that but having no idea how much single phase power the original poster has I let it go with suggesting a good qualified electrician. I have no clue how much current comes with residential 230 V power in the UK? 5.0 HP pumps are not quite a low budget item to begin with. Then as I mentioned starter contactors and now the mention of a VFD and one for each pump. This is going to be an expensive project. I also liked the opening video where the guy figured out a little late his framing should have been on closer centers. :) I have never seen an above ground square of rectangular swimming pool. :) Hot tub yes but larger nope.

Ron

Anyway, nothing else I can think of to add.
 

LesJones

Joined Jan 8, 2017
4,511
Hi Ron,
I live in the UK and the main fuse holder is marked 60/80 amps. I don't know if a 80 or 80 amp cartridge fuse is fitted. This fuse holder is sealed by the supply company so I can't check. I think you could request a higher rating supply cable as a larger house would require a larger supply. I think the TS would be better off paying to have a three phase supply of a suitable rating installed. Like Max I also seem to remember there being a restriction on the size of single phase motor on a normal single phase supply. (But this memory is over 50 years old.)

Les
 

Reloadron

Joined Jan 15, 2015
7,891
Hi Ron,
I live in the UK and the main fuse holder is marked 60/80 amps. I don't know if a 80 or 80 amp cartridge fuse is fitted. This fuse holder is sealed by the supply company so I can't check. I think you could request a higher rating supply cable as a larger house would require a larger supply. I think the TS would be better off paying to have a three phase supply of a suitable rating installed. Like Max I also seem to remember there being a restriction on the size of single phase motor on a normal single phase supply. (But this memory is over 50 years old.)

Les
Hey Les,
You guys over in the UK certainly have a better understanding of what is available. On my side of the pond the new housing gets 240 volt, split phase, 200 amp service at the entry. Older homes like mine can be upgraded which we did. This house originally used knob and tube with 60 amp service.

I guess the original poster just needs to look at what they have and decide where they want to go with it.

Ron
 
Top