Confused BY The Nameplate
- Thread starter Dennis Alwon
- Start date
- Status
- Occupation
- Licensed Electrician
How is the motor failing? Is it the windings in the motor? My guess would be no. Is he getting a whole new pump and motor?
Pool pumps lead a tortured life. They are not the most well built to begin with and the chlorine is rough on the bearings and end bells and starting switch if there is one.
Five years is about right and then it would be time for a new pump seal and bearings but not many motor shops are going to service a motor that size and it is only a couple hundred bucks to buy a whole new one.
I think that motor amp nameplate value is indicating what the amp draw is when loaded to its max service factor loading. If the running amps on high speed are anywhere close to that, you're most likely pumping too much water. A motor runs hotter than normal when running at its SF amps instead of its native horsepower rating.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Apparently the bearings went on the first motor. The pump is fine but the motor is what is the problem. He replaced the seal and the motor.
Being that 240 v is what is available it seems like 208 would be more than 10% that is why I am question how the motor can run on both voltages. Is there some electronics in the motor now that reads the voltage and makes the change?
Being that 240 v is what is available it seems like 208 would be more than 10% that is why I am question how the motor can run on both voltages. Is there some electronics in the motor now that reads the voltage and makes the change?
On these slash rated motors 208 is the minimum voltage it will run on. It will not run (long if at all) at 10% below 208.
230 X 90% = 207
230 X 110% = 253
- Occupation
- Licensed Electrician
If he could have found someone to replace the bearings he likely could have got another five years out of the original motor. It was a mechanical problem that caused the motor to fail, not an electrical one. The pump seal can start to leak a little bit and just the chlorine environment is enough to age the bearings. 208V, 251V, 230V, 240V, 209V, 222V, 233V, wouldn't have mattered.
The motor can run on both voltages because the windings, insulation, fan, etc are configured in such away to make it work, there is no electronics. It's kind of like your car being able to run when it is a quart and half low on oil. The tolerance is built in from the factory.
ptonsparky
Tom
- Occupation
- EC - retired
I just checked voltage @ line side of my well VFD. 248 volts and I would guess that is typical for my house.
208-230 volt motor would have an operating range of 188-253 volts then? Plus/minus 10%.
Add: Apparently, looking at the two comments posted just prior to this, there is still arguments as to the actual allowable voltage range of this motor.
- Occupation
- Licensed Electrician
Huh? I'm of the opinion that the voltage is just fine.
ptonsparky
Tom
- Occupation
- EC - retired
FWIW, I agree, its just fine as applied to this motor.
Why do they bother with adding the 208-230 if it means nothing? Better labeling would be as Hv&Lv has the range. 207-253
IDK what areas of this country have voltage consistently below 207. Ours would typically be closer to 212 on a wye.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
The motor is rated for 208 and 230 volts so the 10% of 230 volts is still OK. The Table in Article 430 states that the 230 volt rating in that table is for 220-240 volts.
Because in T430.248 a motor operating at 208 volts has a different current value than one listed for 230 volts.
No argument. I think the voltage is fine in Dennis’s case.
208-230 means the motor will operate at 207V. NOT 10% below 208.
If it’s a 208 service they will then need a 200V motor.
| Motors rated for 115/208-230 volt and 208-230/460 volt | ||
| These in most cases will operate satisfactorily at 208 volts, but the torque will be 20% - 25% lower. Operating below 208 volts may require a 208 volt (or 200 volt) motor or the use of the next higher horsepower, standard voltage motor. |
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I guess the only motors I remember were something like120/240. This was 208-230 so with the range I wasn't sure if the 10% was still acceptable. Again if they can make a motor that could be wired from 208-230v then why not just go to 240V? That entire 230v is odd to me.
Remember I did a thread on an elevator that was rated 230v. We installed 240v to it and the elevator company made us install a buck boost. Hard to believe 240V was an issue
Remember I did a thread on an elevator that was rated 230v. We installed 240v to it and the elevator company made us install a buck boost. Hard to believe 240V was an issue
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I do appreciate all the comments. The nameplate is new to me with many factors especially the amps having sf and then the amps- never saw that either. I have been out of the field mostly for the past 11 years
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
The 208-230v range rating is based on what is expected at the motor terminals, not to designate the supply voltage.
Such a motor will run satisfactorily on any voltage within 200 to 250 volts, with the current inverse to the voltage.
A motor rated for 208-230/460v is actually rated for 208-230/416-460, but we don't normally see 416v systems.
Such a motor will run satisfactorily on any voltage within 200 to 250 volts, with the current inverse to the voltage.
A motor rated for 208-230/460v is actually rated for 208-230/416-460, but we don't normally see 416v systems.
That motor won’t last with 200V
If it starts at all. Probably will start unloaded, but not with a load.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I was approximating, but there is no one minimum voltage threshold that applies to all 208v motors.
I'm pretty sure that any motor rated for 208v will start and run on a solid 200v, but it will run hotter.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
It will last much longer on 243V than it will on 200
- Status