CPS Elec.
Member
- Location
- Bemidji, MN
Has anyone ever experienced receiving a new motor from a manufacturer with an incorrect nameplate?
Motors from Manufacturer
- Thread starter CPS Elec.
- Start date
- Status
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Absolutely. Weg used to be famous for that.
But what makes you think the nameplate is incorrect?
weressl
Esteemed Member
Seldom seen, but possible. Had one which was actually a different HP motor.
CPS Elec.
Member
- Location
- Bemidji, MN
It a single phase / single rotation motor with a black and a brown wire. Nameplate says .167 hp 2.1fla and 115vac, when bench tested you can hear the thermal overload triping. It runs for about ten seconds, then off for ten seconds, then back on and so on...........checked amps with two different fluke meters and both indicated 9.5 to 10 amps.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Well, right off the bat, 9-10A being pulled by a motor rated for 2.1A would definitely explain the thermal cutout opening!
Your motor is shorted, not mislabeled.
1ph Small motors most often have start and a run windings. When at rest the start winding is connected by the use of a centrifugal. When you the motor is initially energized the switch will open as the motor accelerates up to speed. When in the starting mode the motor draws a great deal of current than in the running mode.
My conclusion would be that your start windings have not disengaged which causes the motor to overheat tripping the thermal overload.
My conclusion would be that your start windings have not disengaged which causes the motor to overheat tripping the thermal overload.
kwired
Electron manager
- Location
- NE Nebraska
If it says 10 hp or more and can easily be picked up with one hand, it is probably wrong:lol:
- Occupation
- Licensed Electrician
More information is needed. What is this motor being used for?
- Occupation
- Licensed Electrician
All single phase motors need something to give them a kick in the right direction. The motor the OP describes is too small to have a starting switch.
kwired
Electron manager
- Location
- NE Nebraska
OP says .167 HP, is that not 1/6? I have seen many 1/6 hp motors with a starting switch. That small of a motor is often not a capacitor start motor, but simply a start winding with a different inductive reactance than the main winding still resulting in the necessary phase shift to create some rotation.
- Occupation
- Licensed Electrician
Shaded pole or PSC would still be my first guess.
kwired
Electron manager
- Location
- NE Nebraska
Yes those types would be more popular on this size of a motor, but I have seen a few 1/6 HP "split phase" motors before. I can't recall any smaller than that though.
My reply was based upon the assumption that the OP had that the motor had been mislabeled by the manufacture.
Also, motors that are often used to drive a squirrel cage motor where the motor itself is mounted within the squirrel cage itself relays of the air being pulled around the motor for cooling.
A number of years ago I replaced blower motor an was amazed at the NP rating of the motor specifically the amp rating and then understood why it needed to be placed in the center of the blower otherwise it would have had no way to cool itself.
- Occupation
- Licensed Electrician
- Occupation
- Licensed Electrician
I don't remember seeing a 1/6 HP split phase motor, I don't doubt they are out there. It is entirely possible I have seen one and paid no attention to what kind it was.
One scenario I have encountered that is similar to what the OP describes are motors with a bad running winding. The motor will start, coast a bit, switch closes and the cycle continues.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Are not most ceiling fans split phase motors, most I have installed have one or two caps and a current relay in the light housing?
- Occupation
- Licensed Electrician
I thought most of them are PSC.
I have an old, old, Hunter Original on the bench right now that is shaded pole. Instead of a reversing switch there is a lever that changes the pitch of the blades. Trying to track down a speed contol switch if you know any sources.
kwired
Electron manager
- Location
- NE Nebraska
I guess that depends on your definition of split phase. They definitely do not have a starting switch that opens when a certain speed is reached. If they did you would not be able to vary the speed or reverse without stopping first. They are typically PSC motors.
- Status