Torque Arrestors

Can anyone tell me the pro's and con's of torque arrestors for submersable pumps, do they realy work or not?
Thanks
Bob

I have a trouble-free .5 hp pump hanging on 15-year-old 1" PVC pipe with no torque arrestor. Mechanically, a so-called "torque arrestor" on a submersible pump does not literally "arrest the torque" of starting or stopping. The drop pipe stops the pump from spinning itself around. As best I can tell, a torque arrestor is more like a surrounding bumper that restricts lateral or "whiplash" movement that might otherwise allow a pump to beat itself to death while attempting to destroy a well casing.

leejosepho said:

The drop pipe stops the pump from spinning itself around. As best I can tell, a torque arrestor is more like a surrounding bumper that restricts lateral or "whiplash" movement that might otherwise allow a pump to beat itself to death while attempting to destroy a well casing.

Click to expand...

Not only will it prevent the pump from slapping the casing, but it will protect the wire feeding the pump as well.

If you need cable guards then you are not using tape correctly to connect the wire to the pipe. If you need torque arresters then your pump is cycling on and off too much. Solve these two problems by using tape on the wires correctly, and by using a huge pressure tank or a Cycle Stop Valve to limit the cycling. Then don't put anything extra down the well that can cause you to get hung up on the way out.

Ditto Ditto

i've always wondered about just getting a soft start starter for the pump. i used to install soft starters or VFD's on every motor controller and they made the startup so much better, but these were 3HP motors at the small end up to 350HP. i'm thinking that $100 for the soft starter would be a good investment. Thoughts?

Soft starters won't work with single phase motors. Soft starters or VFD's don't help much with regular water pumps. Pumps with centrifugal impellers lose head by the square of the pump speed. In other words you have to get to about 85% or 90% speed before the pump will even start moving water. With a submersible you also have to get it up to 50% speed in 1 second to keep the thrust bearing lubricated. Then you must quickly get it to 90% speed before the tank is empty and you have a sudden loss of pressure.

What this means is that these type pumps are not constant torque. There really isn't any torque to speak of until the pump gets to 90% speed. So even when you try to soft start it, the lack of torque at low speed lets the pump start very quickly. I have always had to adjust the torque setting of a soft starter to almost nothing to get any kind of soft start for a pump.

Submersibles hanging on flexible pipe are still going to torque. Even with reduced torque you have to limit the number of times the pump starts to keep from wearing out the drop wire.

Simply using the longest length of the smallest wire possible will give you reduced torque and limit the starting current. This is similar to a resistive type soft starter. Even the pumps using variable speed drives will wear out the wire because they start to many times per day. Not being able to utilize a tank of any size makes these type pumps start for every glass of water, rinsing a toothbrush, or every time the ice maker fills. That is what wears out the wire. It is more the number of torque events, not so much the amount of torque that hurts.