IEC / IEEE Testing

[magneticted]

Is thier an equilvant IEEE test, for testing a Vertical IEC machine by the two frequency method.and ifso, is it still possible measure the stray load losses, as opposed to IEC assumption of 0.5 %. Thanks

 

[motorman]

For efficiency testing, IEEE 112, Method F uses the equivalent circuit of the induction motor to determine its performance from circuit parameters established by test measurements. This test provides acceptable accuracy for starting and running performance. It also should yield the most accurate determination of the losses involved at any load.

The calculated value of full load slip and either the calculated value or assumed value of stray load loss or, alternatively, the values of stray loss prescribed in ANSI C50.41, Section 16 are used.

The dual frequency test determines the temperature rise. Reference: "Primary-Superimposed Equivalent Load Method (Dual-Frequency)," Section 5.2.3. of IEEE 112- Motor is run at no load with 60 Hertz primary power applied.

 

[hec64]

I have tested 1500 HP vertical motors using IEEE 112, method F, but the IEEE also assume values to calculate an equivalent circuit, so the stray losses are still a calculated value. Make sure you can measure the speed of the motor accurately. By using the IEEE moethod B, (Dynamometer) all the losses are measured. The difficult part is to segregate the stray losses. IEEE 112 indicate the problems related on using this method, but I will say it will show that the motor is less efficient than using IEC testing methods.

 

[electricpete]

My version of IEEE112 is 1996...not sure if it is current.

The relevant section appears to be 8.2.3.b



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