replacing 240v Franklin with efficient 110v

Re: replacing 240v Franklin with efficient 110v

I'm extremely satisfied with our Grundfos SQflex pump installed a couple of years ago. It operates just fine from a Xantrex SW2512 inverter at 120VAC. The pump will accept AC or DC in a wide range of voltages.

They are not inexpensive. Most things good, aren't.

I've made past posts about it if you search under my user name. Or feel free to ask questions in this thread or by PM.

Phil

Re: replacing 240v Franklin with efficient 110v

mike90045 wrote: »

you MUST look at the pump curves (power vs water) for the 2 pumps you are considering.

Just because some sales droid says the 110V is more efficient, does not make it so.

At 110V, your starting surge will be MUCH larger than the surge for 240V. And until you go to 3phase or DC, there is not much more efficient than the 3wire Franklin. (note: Grundfos SQflex is a DC MPPT system, pricey)

Dang, I guessed I missed some previous posts that mentioned you're considering two pumps. Certainly not the first (nor last) time I read too fast to absorb all the details.

I just wanted to add that there is NO surge with the SQflex... there's a couple of second delay after the pressure switch says "pump", then the unit slowly starts to increase pumping and power consumption. The power use is monitored by a digital readout on the CU200 pump controller which adds to the expense but is something I'd define as "required".

Phil

Re: replacing 240v Franklin with efficient 110v

mike90045 wrote: »

you MUST look at the pump curves (power vs water) for the 2 pumps you are considering.

Just because some sales droid says the 110V is more efficient, does not make it so.

At 110V, your starting surge will be MUCH larger than the surge for 240V. And until you go to 3phase or DC, there is not much more efficient than the 3wire Franklin. (note: Grundfos SQflex is a DC MPPT system, pricey)

I think you are misleading people about the grundfus pumps. You say they are expensive ( in the $600.00 price range) and need a big power surge. There are 3 different variations of the sq pump. The basic model called just SQ comes in 115 vac and 230 vac version and only needs a 10% power surge when starting. It can use a regular pressure switch also. Then there is the SQ/e which is bigger pumps. The SQ/Flex which you refer to is preety expensive and runs on solar or windpower. I have a sq I am going to install so I don,t need 220 and a lot of batterys to start it. The starting surge should only be about 105 watts over running and should serve my purpose just fine as others here are getting served by thier grundfus SQ pumps. solarvic

Re: replacing 240v Franklin with efficient 110v

ws9876 wrote: »

should I consider a 240v inverter ????the well is my only 240 load..

Depends on current flow, size of wire supplying the pump and the length of that wire run. Many sub pumps will give that info on acceptable wire size and length in the owners manual. The numerous Franklin powered sub pumps I've been involved with in various locations over the years all had such info. Hopefully new ones still do. One system I worked on actually had a booster transformer to up the voltage heading out on a long run to the pump, by 20 volts to counter line loss to the pump. One thing I'm going to play around with sometime when I get a chance, is to auto-transformer reduce the starting voltage of the Franklin powered sub pumps to see how low we can go and still get a start. Instant start is not required and there is no high torque required to start. In the meantime start electrical loads would be greatly reduced. That's what I already do with my fridge and two freezers, which along with added capacitor start, operate in sequence, one at a time on one of my Morningstar SureSine-300 inverters. Fridge takes priority, then the freezer in the house, followed lastly by the freezer in the outside shop. Voltage is reduced about 15% and available current is thus increased by the transformer until the compressors are near operating speed, then a relay bypasses the auto-transformer, and directly connects the compressor to the inverter for normal operation. Been working just fine that way for about 4 years now. Call me nuts, but hey, it works, and compressors are far harder to get moving than centrifugal pumps which have basically no load on them until the impellers get some revs happening.

Re: replacing 240v Franklin with efficient 110v

Ralph Day wrote: »

ws,
I'd go with the Grundfos slo start sub pump. I replaced a 240v power hog with it and it's great. The 240 unit had an enormous surge on start (40+amps), enough to suck the colour out of the tv set and downsize the picture by 4 inches (for a second or so). The Grundfos just clicks on, no measurable current draw, then ramps up to rated load...not noticable on lights, fans or other appliances.

Ralph

Sounds like an awesome motor system! How does electrical reliability and water production compare to the standard Franklin 1/2 HP? Is it basically the same pump with a more advanced motor?

Re: replacing 240v Franklin with efficient 110v

add this to Mikes info

Performance Curves 5 GPM Model 5S - Grundfos
www.us.grundfos.com/web/download.nsf/Pages/.../5s-sub.pdf

a fairly clear graph and other info