# L1 L2 on 110 volt circuit



## Electric_Light

L1=neutral
L2=hot
in that context

Neutral to fan white
Hot to fan's black, blue or red, but the label you showed says its recommend to wire for blue(medium).

The fan is a piece of crap if it can't handle being used on max speed for extended period or there's a fan/motor mismatch causing it to be overloaded. 

Disconnect black, cap off fan's black and red, then connect hot to blue. 
Retry

I don't know what's so confusing.

Polarity is irrelevant in function of a motor. It's just a safety issue if you're switching neutral and leaving the fan always floating above ground.


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## OCRS

Electric_Light said:


> L1=neutral
> L2=hot
> in that context
> 
> Neutral to fan white
> Hot to fan's black, blue or red, but the label you showed says its recommend to wire for blue(medium).
> 
> The fan is a piece of crap if it can't handle being used on max speed for extended period or there's a fan/motor mismatch causing it to be overloaded.
> 
> Disconnect black, cap off fan's black and red, then connect hot to blue.
> Retry
> 
> I don't know what's so confusing.
> 
> Polarity is irrelevant in function of a motor. It's just a safety issue if you're switching neutral and leaving the fan always floating above ground.


So you're saying there's no definitive designation for L1/L2 connections on 110 circuits and that in this instance they are interchangeable ?

If I'm understanding this right, with electric motors, fan white, being the common wire, goes to neutral and whatever fan rpm wire is chosen goes to hot irregardless of the understanding that L1 is supply hot ?

I'm not questioning what you've said, just trying resolve this for my own understanding.


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## DuMass

I don’t know about that particular 120V motor, but many single-phase 208V-240V PSC motors can have their rotation reversed by changing the polarity of the Line 1 and Line 2 connections, so maybe the reversed 120V line / neutral connections with the run capacitor being present are causing a problem, since it sounds like it is a PSC type motor.

Not sure why they designated L1 for neutral and L2 for hot on that motor. Maybe the engineer that designed it was used to automotive electrical… who knows

Is the fan running with the correct rotation to provide air flow for cooling for the air-over motor?


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## OCRS

DuMass said:


> I don’t know about that particular 120V motor, but many single-phase 208V-240V PSC motors can have their rotation reversed by changing the polarity of the Line 1 and Line 2 connections, so maybe the reversed 120V line / neutral connections with the run capacitor being present are causing a problem, since it sounds like it is a PSC type motor.
> 
> Not sure why they designated L1 for neutral and L2 for hot on that motor. Maybe the engineer that designed it was used to automotive electrical… who knows
> 
> Is the fan running with the correct rotation to provide air flow for cooling for the air-over motor?


As far as the rotation goes, it was going in the proper direction. There was an arrow showing proper direction.


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## Electric_Light

DuMass said:


> I don’t know about that particular 120V motor, but many single-phase 208V-240V PSC motors can have their rotation reversed by changing the polarity of the Line 1 and Line 2 connections, so maybe the reversed 120V line / neutral connections with the run capacitor being present are causing a problem, since it sounds like it is a PSC type motor.


No, you can't DumAss. Single phase motors have multiple windings and you change the direction of rotation by changing the linking of windings with respect to each other. You can't change the direction of an induction motor by flipping the plug around in the receptacle. (which is what reversing L1 and L2 is about). 

On a three phase motor, alternating any two wires will reverse the rotation (which is why you need to know the phase rotation, or else risk the motor spinning backward) 



> Not sure why they designated L1 for neutral and L2 for hot on that motor. Maybe the engineer that designed it was used to automotive electrical… who knows


Induction motors can not be run on DC power. Not sure how you came up with that idea.


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## DuMass

Electric_Light said:


> No, you can't DumAss. Single phase motors have multiple windings and you change the direction of rotation by changing the linking of windings with respect to each other. You can't change the direction of an induction motor by flipping the plug around in the receptacle. (which is what reversing L1 and L2 is about).
> 
> On a three phase motor, alternating any two wires will reverse the rotation (which is why you need to know the phase rotation, or else risk the motor spinning backward)
> 
> Induction motors can not be run on DC power. Not sure how you came up with that idea.


I suppose I could have been more specific. This would be at the peckerhead or terminal box where you interchange the connections of the start and run windings, if accessible on that particular motor. 

PSC motors have low starting torque and have been known to run in reverse rotation if the capacitor is weak and a draft happens to turn the fan blades backward at the same time the motor attempts to start. That’s why I mentioned rotation to the OP.

The reference to automotive was simply an observation. If you have ever had to work on something that an automotive electrician has worked on previously, you’ll know what I mean. They seem to consider “ground” as L1 and switch the ground like a commercial electrician would switch a hot.


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