- Location
- Massachusetts
Agitator motors
- Thread starter ptonsparky
- Start date
- Status
By raising the submersible pump to manure slurry level of lower density, its current was brought down to about its full load value and that implies under size pump motor.
kwired
Electron manager
- Location
- NE Nebraska
OP has indicated that this is new and the media is primarily water up to this point.
One other reason for high current, overload.
Possibly from malfunctions or mistakes in designing/selecting equipment.
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
I'll repeat, check the gearing. Current will go up as the cube of the RPM's
ptonsparky
Tom
- Occupation
- EC - retired
I did not look closely, but I believe they are direct drive.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
The propeller pitch also affects the power.
ptonsparky
Tom
- Occupation
- EC - retired
Yes, and that is being investigated.
ptonsparky
Tom
- Occupation
- EC - retired
just the cowboy
Inactive, Email Never Verified
- Location
- newburgh,ny
Is that what you got??
Is that what you got??
When you said agitator I thought top of tank like Jreaf's photo, not something like those things. I think most thought the same.
Is that what you got??
When you said agitator I thought top of tank like Jreaf's photo, not something like those things. I think most thought the same.
ptonsparky
Tom
- Occupation
- EC - retired
I had a hunch that was the case.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
That's a new one on me too, never came across something like that. Apparently it's specifically a manure agitator, and the company is from Turkey.
http://www.e-y-s.com/ Click on the little British flag to get the English version.
It's highly unlikely that a sealed one-piece unit like that was not engineered correctly, meaning I doubt the gear ratio or blade pitch is incorrect.
But here's another angle. These things have IEC motors in them, and the literature says that the same unit is good for 230 or 380V 50Hz, or 480V 60Hz (but it would NOT be good for 240V 60Hz). You said in the beginning that it was supposed to pull 21A, and later said it was 15HP. That implies 480V (you didn't say, so I had to deduce).
On that motor, you would have had to connect it in the Star pattern for 480V operation, the nameplate may have said 380V, but it would be the same connections. If you connected it in Delta, the motor is getting low voltage (as far as IT is concerned). The motor equivalent voltage would be 277V, or 58% of what it needs. Torque output would then be very low, about 33% peak torque, even though the speed would be the same. That means as soon as it sees any significant load, slip would increase and it will pull high amps in an attempt to get back to normal speed. When you raise it up and decrease the load, it can do it, but when you lower it, you are overloading it.
Triple check your connections.
http://www.e-y-s.com/ Click on the little British flag to get the English version.
It's highly unlikely that a sealed one-piece unit like that was not engineered correctly, meaning I doubt the gear ratio or blade pitch is incorrect.
But here's another angle. These things have IEC motors in them, and the literature says that the same unit is good for 230 or 380V 50Hz, or 480V 60Hz (but it would NOT be good for 240V 60Hz). You said in the beginning that it was supposed to pull 21A, and later said it was 15HP. That implies 480V (you didn't say, so I had to deduce).
On that motor, you would have had to connect it in the Star pattern for 480V operation, the nameplate may have said 380V, but it would be the same connections. If you connected it in Delta, the motor is getting low voltage (as far as IT is concerned). The motor equivalent voltage would be 277V, or 58% of what it needs. Torque output would then be very low, about 33% peak torque, even though the speed would be the same. That means as soon as it sees any significant load, slip would increase and it will pull high amps in an attempt to get back to normal speed. When you raise it up and decrease the load, it can do it, but when you lower it, you are overloading it.
Triple check your connections.
ptonsparky
Tom
- Occupation
- EC - retired
My guys connected it. 9 lead Delta. I discussed the possibility of 50hz vs 60 with the area tech that works with these and he confirmed the label did say 60 Hz and 480v. He also double checked connections and confirmed them. My help was slightly insulted when I suggested maybe...
The tech did tell me the label was a bit screwed in that it showed hi/low amps with voltage hi/low as well.
The tech said a lot of these are installed in the States so the HZ issue should not be a problem. Right now they are looking at the prop.
That said, I will personally look tomorrow. FWIW.
ptonsparky
Tom
- Occupation
- EC - retired
where did you get the literature?
The diagram we were given is for 9 lead delta. The motor is 9 lead. I see no way to change it to wye. I can ohm one out tomorrow to see if it is delta or wye connected internally.
- Occupation
- Licensed Electrician
Where indeed! I have never heard of a 9 lead IEC motor. I tried the link and didn't get anything of value. I think Jraef just knows stuff.
Are the leads numbered NEMA style or lettered?
ptonsparky
Tom
- Occupation
- EC - retired
Both.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
I didn't see a wiring diagram, I saw a spec sheet that said it was set up for 230, 380, or 460V operation.
If it it a true 9 lead motor, then it's not an IEC. But it might be a 12 lead where they already connected 3 of them internally. It's hard to figure out what some of these IEC mfrs do to be able to sell their products here, I've come across some strange stuff.
I've got one now where the motor was sold as a "460V" motor, but it failed to get to full torque and kept tripping on OL in the VFD. Turned out it was a 660Y380V 50Hz design, so when used at 60Hz, became a 792/460V motor, which meant you had to connect to the LOW voltage winding pattern (Delta). The nameplate only said High and Low on the connection diagram, but then listed 460V as the only voltage, so the guy hooked it up to the High connection, thinking it was 230/460. The only reason I knew what had happened is that I came across it before, with large Weg motors from Brazil.
If it it a true 9 lead motor, then it's not an IEC. But it might be a 12 lead where they already connected 3 of them internally. It's hard to figure out what some of these IEC mfrs do to be able to sell their products here, I've come across some strange stuff.
I've got one now where the motor was sold as a "460V" motor, but it failed to get to full torque and kept tripping on OL in the VFD. Turned out it was a 660Y380V 50Hz design, so when used at 60Hz, became a 792/460V motor, which meant you had to connect to the LOW voltage winding pattern (Delta). The nameplate only said High and Low on the connection diagram, but then listed 460V as the only voltage, so the guy hooked it up to the High connection, thinking it was 230/460. The only reason I knew what had happened is that I came across it before, with large Weg motors from Brazil.
- Occupation
- Licensed Electrician
So in the case of the OP he's doomed, there's no way to hook it up other than high or low voltage. There's no way I'd hook it up for low volts and put it on 480V without a factory rep there to throw the switch along with a spare motor in the back of his truck.
ptonsparky
Tom
- Occupation
- EC - retired
Turns out another customer in Minnesota has a similar problem, the props are wrong.
mgookin
Senior Member
- Location
- Fort Myers, FL
Don't you love it!
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
I wonder if they specified different props for 50Hz versus 60Hz because of the cube law dependence of power on speed?
The wrong prop would then try to pull 1.5 times the design power from the motor.
The wrong prop would then try to pull 1.5 times the design power from the motor.
- Status