mstrlucky74
Senior Member
- Location
- NJ
What does motor phase rotation entail for an electrician? I know what it means but curious as to what is used and needs to be done. Thanks.
But under the 2017 code, in a building with multiple voltage systems, you are required to "flop" the two wires at the motor, not at the starter.IME, decouple and "bump" the motor to make certain it is turning in the proper direction. This method is better than any meter devised.
If turning the wrong direction, we flop any two of the three supply wires.
I don't believe anyone's got that far... yet! :slaphead:But under the 2017 code, in a building with multiple voltage systems, you are required to "flop" the two wires at the motor, not at the starter.
I like that way best too. Sometimes you gotta use a rotation meter though. Pumps for one are not always easy to uncouple.IME, decouple and "bump" the motor to make certain it is turning in the proper direction. This method is better than any meter devised.
If turning the wrong direction, we flop any two of the three supply wires.
But under the 2017 code, in a building with multiple voltage systems, you are required to "flop" the two wires at the motor, not at the starter.
They forgot what it says in 90.1Good grief. What was the substantiation?
One must first know what they forgot.They forgot what it says in 90.1![]()
There was none. They just changed the scope of Article 210 to include motor circuits which triggers the application of 210.5 for the motor conductors. In the 2014 code the scope of 210 excluded motor circuits. Not sure they even know the results of the change.Good grief. What was the substantiation?
See if this ECM link helps: http://ecmweb.com/content/determining-motor-rotation-direction
IME, decouple and "bump" the motor to make certain it is turning in the proper direction. This method is better than any meter devised.
If turning the wrong direction, we flop any two of the three supply wires.
Putting power to the motor very briefly so you can observe shaft rotation before the motor manages to destroy that thing it's coupled to which isn't supposed to spin backwards.So when you "bump"... what are you actual doing?
I don't believe anyone's got that far... yet! :slaphead:
:angel:
I don't believe anyone's got that far... yet! :slaphead:
All the more reason to use same color motor supply conductors and phase tape. In many to most cases, it is easier to flop wires at the starter. Under 2017 can we not flop wires at starter and change phase tape at both starter and motor?
:angel:
No, but they do have final overcurrent device and an outlet which, for motors, would be the pecker head. Red, black, blue across the top of starter and/or disconnect better have red, black, blue, across the bottom.not all motors have starters...right!? Disconnect yes.
Revise my statement to last device before motor in lieu of starter. And this would only be where motor terminations use a means not easily reversible.not all motors have starters...right!? Disconnect yes.
Forward in time.I sure haven't. Can you point me in a direction?
From the 2017 NEC.210.1 Scope
This article covers branch circuits except for branch circuits that supply only motor loads, which are covered in Article 430. Provisions of this article and Article 430 apply to branch circuits with combination loads.
The 2017 goes on to say that 430 can modify 210, but there is nothing in 430 that says 210.5 does not apply to motor circuits.210.1 Scope. This article provides the general requirements for branch circuits.