OT: vertical turbine pump issues

The original post stated they have 2 pumps and pump #2 failed
I have see and worked on system with multiple well with pumps all feeding the same system.
Any single pump failure should have tripped an alarm and the backup pump should have started long before the tank level went into alarm. Most modern system have email alerts to multiple people with any alarm.
if the first alarm was the low water level in the tank
it sure looks to me like it's time for an upgrade
I have seen systems with over 10 well pumps spread out over 10 square miles feeding a common tank or tanks with any one fault will and alarm and emails sent to alert the operators.
Most modern systems have both a land line and cellular or radio communications back the main operator station the tank level going into alarm as the first alarm is unexceptionable

They have plenty of alerts and back up pumps

The thing is the softstart never tripped and no breaker tripped.

I think what GaryS is getting at is that the fact that the call for water went unanswered. Whether a pump failed or whatever, it would be better to generate an alarm if a pump was called to run, but no water came in. It is difficult to program all the possibilities, but we should try!

Their flowmeter is not tied into the controls at all, just for observation. But it would be good to monitor that from the plc and generate a fault as you describe.

Its a very small back-woodsy plant. Thanks for the suggestions!

I know that this may seem like an obvious question but I didn't see the answer in any of the post's Is their a check valve or a foot valve on the pump ?
If so is it working ?
What is the lift from the well to the top of the storage tank ?
what is the pipe diameter and length ?
All these will have an effect on thee pump
Many years ago I got a call to quarry that had a 250Hp submersible pump in the pit to pump out the water that accumulated in the pit. about every 3 months the pump would fail with a broken shaft things were getting expensive and they wanted answers.
as it turn out when the pump stopped the discharge pipe would drain back tot he pit through the pump turning it backwards at a high speed. it took about 15 mins to drain
but they used this same pump to fill the water truck and the operator would restart the pump while it was spinning in reverse an snap the shaft.
we ended up installing a delay timer to prevent a restart until the pump stopped.
never had a problem after that.
I just though i would through that out there for thought

Do these pumps have an electric pump control valve? I would make sure that is working correctly. If it is not closing completely you can get partial reverse water flow that would lock in the anti reverse ratchet. Then if you had a pump call to run in that condition, that could put stress on the line shaft. Repeated starts with backward water flow through the pump can break the shaft.
There should be a restart delay timer so that when the pump gets a call to run, it can not restart until the timer time out.

Pumps this large should have either a slanted disc check valve or an electric pump control valve. a regular check valve introduces to much shock into the system especially if there is an interruption of the power supply.
If there is a regular check valve or slanted disc check valve the soft start MUST have a pump control option that ramps down the motor slowly rather than letting it coast to a stop. It's all speculation given the information you shared with us.
A picture is worth a thousand words.

GaryS said:

A Soft Start can never reverse the rotation / phase, most if not all are SCR's

Click to expand...

Not so fast. A few manufacturers have reverse jogging, which fires the 1/2 cycles out of sequence and appears to the motor as lower frequency reverse phase rotation. See Emotron, Aucom, and a few others.

GaryS said:

as it turn out when the pump stopped the discharge pipe would drain back tot he pit through the pump turning it backwards at a high speed. it took about 15 mins to drain
but they used this same pump to fill the water truck and the operator would restart the pump while it was spinning in reverse an snap the shaft.
we ended up installing a delay timer to prevent a restart until the pump stopped.

Click to expand...

That seems like the most likely cause to me.