AC Motor Name Plate - Terms & Meanings

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When you see the name plate of an electric motor, you will find many terms which defines the performance characteristics of the motor. These include supply voltage, rated full load current, motor horse power, motor speed in RPM, frequency of power supply, motor frame, motor duty, AC motor insulation class, motor design, service factor, motor efficiency, power factor, number of poles, winding type connection-star or delta and many more. Shown below is a typical
NEMA motor name plate design.


''NAME OF MANUFACTURER''
ORDER NO IZ4560089590
TYPE HIGH EFFICIENCY FRAME 286T
H.P. 30 SERVICE FACTOR 1.15 3 PH
AMPS 25 VOLTS 415 Y
R.P.M. 1800 HERTZ 50 4 POLE
DUTY CONT. DATE 02/26/2015
CLASS INSUL F NEMA
DESIGN
B NEMA
NOM. EFF.
90
"ADDRESS OF MANUFACTURER" "Safety Standard Symbol here"


The terms on the above AC motor name plate and their various meanings as applied in industry are described in the table below:

Name Plate Terms Meaning
Volts Rated terminal supply voltage.
Amps Rated full-load supply current. Some motor name plate have FLA - Full load Current
H.P. Rated motor output in Horse power
R.P.M Rated full-load speed of the motor.
Hertz Rated supply frequency.
Frame External physical dimension of the motor based on the NEMA standards
Duty Motor load condition, whether it is continuos load, short time, periodic, etc.
Date Date of manufacturing.
Class Insulation Insulation class used for the motor construction. This specifies max. limit of the motor winding temperature.
NEMA Design This specifies to which NEMA design class the motor belongs to.
Service Factor Factor by which the motor can be overloaded beyond the full load.
NEMA Nom.
Efficiency
Motor operating efficiency at full load.
PH Specifies number of stator phases of the motor.
Pole Specifies number of poles of the motor.
Y Specifies whether the motor windings are Star (Y) connected or Delta (Δ) connected.
Safety Standard Symbol Specifies the motor safety standard.