Off topic, but I thought someone might have some good experience.
One of our customers is a water treatment facility to provide fresh water to the the town. They have 2 vertical turbine pumps that pump water up the hill into the water tank. Voltage is 480 and FLA is 120A.
Last Sunday, they suddenly reported that turbine 2 is making a terrible noise inside at the control panel. It is on an old Saftronics AS6 soft start.
When I arrived, they had it off. We put it in hand and it would try to start. The lights in the plant would begin flickering and the wiring in the conduits would buzz like crazy. My amp meter was showing 300-400s on each leg, but the amperage was very far from stable. We went out by the pump and listened to it for a few seconds out there and it made a terrible electrical buzz but it also had a mechanical noise like the rotor would be dragging.
At first I thought maybe the pump was jammed and we had a stall. But you could spin the pump shaft freely. Then we got to looking and noticed that the pump shaft was no longer connected to the rotor of the motor. Its the hollow bore style with the anti-reverse balls device on the top. We took the top cover of the motor off and all 4 3/8" bolts that fastened the motor to the pump were all sheared off. Odd. But both the motor and pump spun freely.
We also expected that at this point the motor should run okay, but it wasn't. A computerized winding test told us that while the motor megged fine, it had a winding-winding short. Also I ohmed the soft start from L1-T1, L2-T2, L3-T3 and the ohm readings were very far from balanced.
When we craned the motor out, we decided to pull the pump as well because we had the hunch that the pump shaft might have busted. And sure enough, that is what had happened.
So it is kind of a puzzle to us, it had been running fine, but suddenly we have a broken pump shaft, 4 sheared bolts, motor windings shorted, and a bad soft start. The customer insists that all the check valves were working. We noticed that for some reason all the balls were missing in the anti-reverse device, which would have allowed it to spin excessively in the wrong direction.
the pump is coming in to our shop for inspection, but the customer wanted to scrap the motor so we do not get to evaluate it.
We haven't seen this before. We are unsure what was cause and what was effect. Any thoughts on this??
One of our customers is a water treatment facility to provide fresh water to the the town. They have 2 vertical turbine pumps that pump water up the hill into the water tank. Voltage is 480 and FLA is 120A.
Last Sunday, they suddenly reported that turbine 2 is making a terrible noise inside at the control panel. It is on an old Saftronics AS6 soft start.
When I arrived, they had it off. We put it in hand and it would try to start. The lights in the plant would begin flickering and the wiring in the conduits would buzz like crazy. My amp meter was showing 300-400s on each leg, but the amperage was very far from stable. We went out by the pump and listened to it for a few seconds out there and it made a terrible electrical buzz but it also had a mechanical noise like the rotor would be dragging.
At first I thought maybe the pump was jammed and we had a stall. But you could spin the pump shaft freely. Then we got to looking and noticed that the pump shaft was no longer connected to the rotor of the motor. Its the hollow bore style with the anti-reverse balls device on the top. We took the top cover of the motor off and all 4 3/8" bolts that fastened the motor to the pump were all sheared off. Odd. But both the motor and pump spun freely.
We also expected that at this point the motor should run okay, but it wasn't. A computerized winding test told us that while the motor megged fine, it had a winding-winding short. Also I ohmed the soft start from L1-T1, L2-T2, L3-T3 and the ohm readings were very far from balanced.
When we craned the motor out, we decided to pull the pump as well because we had the hunch that the pump shaft might have busted. And sure enough, that is what had happened.
So it is kind of a puzzle to us, it had been running fine, but suddenly we have a broken pump shaft, 4 sheared bolts, motor windings shorted, and a bad soft start. The customer insists that all the check valves were working. We noticed that for some reason all the balls were missing in the anti-reverse device, which would have allowed it to spin excessively in the wrong direction.
the pump is coming in to our shop for inspection, but the customer wanted to scrap the motor so we do not get to evaluate it.
We haven't seen this before. We are unsure what was cause and what was effect. Any thoughts on this??