Soft start for 3/4 hp water pump

[cbisson]

Has anybody ever used a soft start on a 3/4 hp single phase 240v well pump? I have recently installed a 48v /4400w Magnum inverter backed up by 600ah of LiFePo4 batteries. The system works great powering critical loads in my house. Next step is solar panels.

The issue I am trying to solve for is that when the well pump starts the lights dim and then go bright for literally a split second as the inverter ramps up to handle the inrush current and then has to quickly ramp back down once the pump has started. The same thing happens when I'm running on a generator as the VR has to quickly respond to the inrush current load and then back off, all in a split second. The pump is not a submersible.

I have done some digging and it looks like the device at the link below may solve the problem but I have 0 experience with this and am hoping that someone here may already have been down this road. The label on the motor states that at 240v the draw is 6.3a with a max load of 7.4a. I'm not sure if the 7.4 accounts for the inrush current though.

ATS01N109FT - soft starter for asynchronous motor - ATS01 - 9 A - 110..480V - 1.1..4 KW | Schneider Electric USA

Schneider Electric USA. ATS01N109FT - soft starter for asynchronous motor - ATS01 - 9 A - 110..480V - 1.1..4 KW.

www.se.com

 

[BentleyJ]

I have installed a Hyper Engineering soft starter on a 4 ton AC, scroll compressor, works super good. A soft starter can reduce inrush by up to 70%. I cannot specifically comment on the item you linked above, however, Schneider equipment is generally mid to high quality.
I'm running a Conext XW+ 6848 Inverter and have been happy with it. In fact, it starts and runs the 4 ton AC no problem.

 

[BentleyJ]

You said, "The label on the motor states that at 240v the draw is 6.3a with a max load of 7.4a. I'm not sure if the 7.4 accounts for the inrush current though."

BTW, the particular Schneider soft starter you linked to is rated for 1.1KW max for a single phase motor. At 240V with a 7.4A pump load you will need a soft starter rated for 1,776KW which would imply a device rated for 2KW.
This is the Hyper Engineering model number you will need SS1B08-16SN (230V, 60/50Hz, 08-16 FLA).
Schneider probably has something equivalent.

 

[cbisson]

Thank you BentleyJ. I'll check out the Hyper Eng devices. I still have to figure out the wiring. This is not a capacitor start motor so I have to figure out if it will work with just 2 hots and a ground. FWIW the inverter has no trouble at all starting the pump, it just makes the lights go dim/bright for a fraction of a second adapting output to handle the inrush.

 

[Steve_S]

North America: 240VAC = Split Phase, 2 legs of 120VAC opposing phase.
EU+" 210-240 VAC @ 50Hz is typically Single Phase (NOT Compatible with North American 60Hz)

Start Surge for a pump under load is typically 3X the rated amperage on label. Water Pumps are under load as they push water immediately.
Example: An Air Compressor with 0-PSI pressure in tank will have No Load to start but as pressure builds that adds load & increases amps pulled.

Top Quality Softstarters here by ABB.

https://new.abb.com/low-voltage/products/softstarters-new

 

[Birdog]

Has anybody ever used a soft start on a 3/4 hp single phase 240v well pump? I have recently installed a 48v /4400w Magnum inverter backed up by 600ah of LiFePo4 batteries. The system works great powering critical loads in my house. Next step is solar panels.

The issue I am trying to solve for is that when the well pump starts the lights dim and then go bright for literally a split second as the inverter ramps up to handle the inrush current and then has to quickly ramp back down once the pump has started. The same thing happens when I'm running on a generator as the VR has to quickly respond to the inrush current load and then back off, all in a split second. The pump is not a submersible.

I have done some digging and it looks like the device at the link below may solve the problem but I have 0 experience with this and am hoping that someone here may already have been down this road. The label on the motor states that at 240v the draw is 6.3a with a max load of 7.4a. I'm not sure if the 7.4 accounts for the inrush current though.

ATS01N109FT - soft starter for asynchronous motor - ATS01 - 9 A - 110..480V - 1.1..4 KW | Schneider Electric USA

Schneider Electric USA. ATS01N109FT - soft starter for asynchronous motor - ATS01 - 9 A - 110..480V - 1.1..4 KW.

www.se.com

I didn't have any luck with my soft starts. As far as Schnider goes, they told me their soft starts are only designed to cycle 4 times an hour. Once every 15+ minutes. Try taking a shower like that. I tried buying a hyper but after doing so the mfr told me it wasn't suitable for my application.

 

[Supervstech]

Thank you BentleyJ. I'll check out the Hyper Eng devices. I still have to figure out the wiring. This is not a capacitor start motor so I have to figure out if it will work with just 2 hots and a ground. FWIW the inverter has no trouble at all starting the pump, it just makes the lights go dim/bright for a fraction of a second adapting output to handle the inrush.

Are you certain there isnt a capacitor internal with the motor?
THat large a motor without a cap would be unusual unless it was 3 phase.

 

[Birdog]

Are you certain there isnt a capacitor internal with the motor?
THat large a motor without a cap would be unusual unless it was 3 phase.

It is 3 phase. 230v single phase. It kicks off at about 34 amps and runs at about 12-14. It's a Sta Rite Jet Pump, see pic.

 

[Supervstech]

It is 3 phase. 230v single phase. It kicks off at about 34 amps and runs at about 12-14. It's a Sta Rite Jet Pump, see pic.View attachment 148630

If it is pulling 12-14a either it is wired for 120V, or something is wrong with it.
Dataplate shows max running draw at 9.6A...

 

[Birdog]

Finally bit the bullet and drilled a new well so I could abandon my jet pump and incorporate a grundfos 10 SQE10-290 submersible pump with soft start. Went from a well with 2" casing to one with 4". Attached is my amps used while filling the 80 gal pressure tank from zero start to finish. No more flickering lights!

 

[Solar Guppy]

Right long term solutions always wins!