Standard Motor Catalog

Section TR Technical Reference Guide

Table 43: HP and kW Power Conversions Multiply By To Obtain Horsepower (HP) 0.746 Kilowatts (kW) Kilowatts (kW) 1.341 Horsepower (HP) 3.0 Motor Voltages/Frequencies A line frequency of 60 HZ is standard for North America, however, outside the United States, many countries are standardized on 50 HZ. Common voltages and frequencies are summarized below. Table 44 50 HZ 220 240 380* 400* 415 500 660 690 60 HZ 230 - 440 460 480 575 - - * Sometimes seen at 60 HZ

Figure 35

4.0 Motor Speeds

Table 45 Synchronous Speeds at No Load for 50 HZ and 60 HZ AC Motors

Number of Poles

60 HZ

50 HZ

2 4 6 8

3600 1800 1200

3000 1500 1000

900

750

5.0 Motor Dimensions NEMA dimensions: Expressed in inches IEC dimensions: Typically given in millimeters (mm) IEC uses a different letter nomenclature than NEMA to represent various motor dimensions. The following tables and figures summarize the differences for key dimensions. NEMA typically assigns the shaft diameter (U) and shaft lengths (N-W) based on assigned frame sizes. IEC has standard shaft dimensions but they are independent of frame size. Table 46: NEMA/IEC Comparison of Basic Motor Dimension Letters Motor Dimension IEC NEMA Overall motor length L C Shaft diameter D U Shaft height H D Closest mounting hole centerline to DE shaft shoulder C BA Length of shaft extension from shaft shoulder E N-W Distance from mounting holes in mounting feet (Side view) B 2F Distance from mounting holes in mounting feet (Front view) A 2E

TECHNICAL REFERENCE GUIDE

TR.49

Data subject to change without notice. 03/24 • www.wolongamerica.com