Soft start on 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 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 Global

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

www.se.com

Thanks as always

 

[Scoobyshep]

Amprobe with a min max function is your friend. In the loosest mathmatical sense your inrush spike shouldn't be higher than 9 amps, But theres alot of unknowns there.

Softstart is the way I would go.

 

[gelane]

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 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 Global

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

www.se.com

Thanks as always

How many amps is it drawing when running ?
Does it have a capacitor on it ?
Have you checked it if it does ?

I install soft starts on marine ac units all the time. Did one today.
I am not familiar with the unit you are looking at.
I believe the units I use are Micro Air.
You can call them and they are very helpful.

 

[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 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 Global

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

www.se.com

Thanks as always

How many amps is it drawing when running ?
Does it have a capacitor on it ?
Have you checked it if it does ?

I install soft starts on marine ac units all the time. Did one today.
I am not familiar with the unit you are looking at.
I believe the units I use are Micro Air.
You can call them and they are very helpful.

Thank you both for your responses.

 

[Josephml21]

Bumping an old thread here but I installed a soft start on my 2.5 ton AC unit. My house is mostly gas with the AC and 3 kids tvs, gaming systems, 2 fridges and a deep freezer being most of my electrical load. I use to run a 803 and downsized to a 802.

Needless to say when the AC would cycle on it would hit the 802 hard. The lights to dim, cause a pretty nasty HZ swing for a second until the governor caught up and the in rush load dropped off.

This is a project that I've been wanting to tackle for some time now and finally got around to it so here are my numbers.

In rush current is normally 64 amps while the AC unit starts. The soft start got it down to 20.4 amps. Once running the AC should draw about 13.5 amps and in the picture attached it's drawing 9.3 amps. It was starting to cool off outside at this point. During the hottest part of the day it was drawing 11 amps. Still not a bad improvement.

I will say the unit goes through a learning procedure for the first 5 starts to improve the starting sequence. My numbers are after 4 starts so it's got one more learning cycle but I don't think there is too much more room for improvement.

I've read these units can be used on well pumps and compressors, I guess anything that has a motor. Additionally I also read that if you reach out to micro air and tell them what you are trying to do they'll build a unit to suit your needs.

Good luck everyone

 

[Triple Jim]

Once running the AC should draw about 13.5 amps and in the picture attached it's drawing 9.3 amps. It was starting to cool off outside at this point. During the hottest part of the day it was drawing 11 amps. Still not a bad improvement.

That looks like a nice soft start unit, thanks. Micro-Air says that running current is not reduced, so I think you're just seeing the normal running currents that vary as the indoor and outdoor temperatures change. That 13.5 amps is the maximum expected current with the worst temperatures you might encounter.

 

[Coug]

Alternative option, since that battery bank shows you've got some decent investment into the system, is looking at a 48V DC water pump.

Will require a little larger cables, but you gain some efficiency in not having to convert from the DC power of the batteries to AC power through the inverter.

Just food for thought. Maybe when your current pump fails/wears out you might consider it

EDIT: just one example pulled up quickly, .8hp pump

Robot or human?

 

[Russ Knight]

Bumping an old thread here but I installed a soft start on my 2.5 ton AC unit. My house is mostly gas with the AC and 3 kids tvs, gaming systems, 2 fridges and a deep freezer being most of my electrical load. I use to run a 803 and downsized to a 802.

Needless to say when the AC would cycle on it would hit the 802 hard. The lights to dim, cause a pretty nasty HZ swing for a second until the governor caught up and the in rush load dropped off.

This is a project that I've been wanting to tackle for some time now and finally got around to it so here are my numbers.

In rush current is normally 64 amps while the AC unit starts. The soft start got it down to 20.4 amps. Once running the AC should draw about 13.5 amps and in the picture attached it's drawing 9.3 amps. It was starting to cool off outside at this point. During the hottest part of the day it was drawing 11 amps. Still not a bad improvement.

I will say the unit goes through a learning procedure for the first 5 starts to improve the starting sequence. My numbers are after 4 starts so it's got one more learning cycle but I don't think there is too much more room for improvement.

I've read these units can be used on well pumps and compressors, I guess anything that has a motor. Additionally I also read that if you reach out to micro air and tell them what you are trying to do they'll build a unit to suit your needs.

Good luck everyone

Thank you for this. We just applied to become a dealer for this company.