Page 162 - Electromechanical Devices and Components Illustrated Sourcebook

124 Electromechanical Devices & Components Illustrated Sourcebook

A three-phase motor may be converted to a single-phase Mounts
motor with a loss of approximately one-third of its power.
Figure 6-76 shows a commercial single- to three-phase adap-
tor used to convert motors. These units operate in the same
Front Panel
manner as a rotary converter, except that the power is taken
from the motor shaft. Power Indicator

NEMA Motor Frame Dimensions Label

The National Electric Manufactures Association (NEMA) Cabinet
publishes standard dimensions that are used for electric motor
manufacturing. Most motor manufactures adhere to these
standards. If a motor is encountered that does not conform to
these standards, then it was, most likely manufactured for a Single-Phase Power To Three-Phase Motor
special application. Figure 6-77 is a table that provides stan- Figure 6-76 Commercial Single- to Three-Phase
dard NEMA motor frame dimensions. Converter

U (Shaft Diameter) AB S (Key Set)

H D
(Mounting
Holes)

2F BA NW E E

FRAME D E 2F H U BA NW S
48 3.00 2.12 2.75 0.30 0.50 2.50 1.50 Flat
56 3.50 2.44 3.00 0.30 0.63 2.80 1.88 0.19
143 3.50 2.75 4.00 0.30 0.75 2.30 2.00 0.19
143T 3.50 2.75 4.00 0.30 0.88 2.30 2.25 0.19
145 3.50 2.75 5.00 0.30 0.75 2.30 2.00 0.19
145T 3.50 2.75 5.00 0.30 0.88 2.30 2.25 0.19
182 4.50 3.75 4.50 0.40 0.88 2.80 2.25 0.19
182T 4.50 3.75 4.50 0.40 1.13 2.80 2.75 0.25
184 4.50 3.75 5.50 0.40 0.88 2.80 2.25 0.19
184T 4.50 3.75 5.50 0.40 1.13 2.80 2.75 0.25
203 5.00 4.00 5.50 0.40 0.75 3.10 2.25 0.19
204 5.00 4.00 6.50 0.40 0.75 3.10 2.25 0.19
213 5.30 4.25 5.50 0.40 1.13 3.50 3.00 0.25
213T 5.30 4.25 5.50 0.40 1.38 3.50 3.38 0.31
215 5.30 4.25 7.00 0.40 1.13 3.50 3.00 0.25
215T 5.30 4.25 7.00 0.40 1.38 3.50 3.38 0.31
224 5.50 4.50 6.75 0.40 1.00 3.50 3.00 0.25
225 5.50 4.50 7.50 0.40 1.00 3.50 3.00 0.25
254 6.30 5.00 8.25 0.50 1.13 4.30 3.37 0.25
Figure 6-77 NEMA Motor Frame Dimensions