DC Buyer's Guide

Power Supplies

Motor Operation from Rectified Power Supplies Motors are suitable for operation with MG sets or with the rectified power supplies described below: a. Single-phase, full wave, 60 cycle (Power Supply Identification K) Only motors rated 7.5 HP or less, 180 Volts, are suitable for this type of power supply. These ratings do not require an external reactor. For AC supplies other than 230 volts, 60 cycle, refer to Wolong . b. Three-phase modified, 60 cycle (Power Supply Identification D) This power supply has three controlled rectifiers and three uncontrolled rectifiers plus a free-wheeling rectifier. It produces the three pulses per cycle. Motors rated 250 HP or less in frames CD5010AY and below may be used on this type of power supply. No external reactors are required for motors in frames CD5010AY and below, although improved operation at low speeds may be obtained on frames CD365AT-CD5010AY using a reactor. The 240 volt motors are based on 230 volt, three-phase, 60 cycle AC voltage applied to the rectifier bridge, while the 500 volt motors are based on 460 volt, three-phase, 60- cycle AC voltage applied to the rectifier bridge. c. Three-phase, full wave 60 cycle (Power Supply Identification C) This power supply has six controlled rectifiers and produces six pulses per cycle. The 240 volt motors are based on 230 volt, three-phase, 60-cycle AC voltage applied to the rectifier bridge, while the 500 volt motors are based on 460 volt, three-phase, 60-cycle AC voltage applied to the rectifier bridge. Motors in AC voltage CD6000-CD6900 are suitable only for operations from six-controlled, 3 leg power supplies. d. Three-phase, full wave other than 60-cycle, 240 volt DC (230 volt AC) or 500 volt DC (460 volt AC) Power supplies of this type require identification as follows: M/N F-V-H-L where: M = a digit indicating total pulses per cycle. N = a digit indicating controlled pulses per cycle. F = free wheeling (this letter appears only if free wheeling is used). V = three digits indicating nominal line-to-line AC voltage to the rectifier. H = two digits indicating input frequency in hertz L = one, two, or three digits indicating the series induc tance in millihenries (may be zero) to be added externally to the motor armature circuit.

If input frequency is 60 hertz and no series inductance is added externally to the motor armature circuit, these quantities need not be indicated and shall be permitted to be omitted from the identification of the power supply. However, if one of these qualities is indicated, then both shall appear to avoid confusion (NEMA MG1-2009, part 10.61.2). For other types of power supplies, refer to Wolong . Standard shunt field voltages are as shown under field voltage modification. (Refer to the Modifications Section Item 34) Reactors All DC motor ratings in CD6000-CD6900 frames operating on twelve pulse, three phase rectified power supplies and all ratings in CD6000-CD6200 frames operating on less than twelve pulse rectified power supplies do not require external inductance. DC motor ratings in CD6700-CD6900 frames operating on less than twelve pulse rectified power supplies may require external inductance to limit the armature circuit current ripple to assure acceptable commutation and long brush, commutator and bearing life. Armature current ripple is determined by power supply type, ration of DC to AC line voltage, and total circuit inductance. For DC motors in CD6700-CD6900 frames rated at the following horsepower and speed combinations or for any rating in CD6700-CD6900 frames having an armature circuit inductance of 0.2mH and less, we recommend a 0.5mH external reactor. Our experience indicates that this is especially true of applications where the motor is operated at rated load and speed or higher for extended periods. Horsepower Base Speed (RPM) 1000-1250 850 and above 1500 650 and above 1750-3000 500 and above When external reactance is used, it should be installed in series with the A1 leads of the motor. The reactor should be sized to have the following: Continuous and overload DC rating equal to the motor rating. AC RMS current rating equal to 25% of motor DC rated current for large variance between AC supply and rectified DC voltage. Frequency rating equal to 360 Hz Enclosure equal to NEMA 1 or as suitable for environment. Following is one source for the reactors described above: Transformer Engineering Corporation 2550 Brookpark Road, Cleveland, Ohio 44134 Ph. 1-(216)-741-5282

Motor Pricing General Information

Other Information Application Information Outline Dimensions Accessories and Modifications

DC Current

Design

%AC RMS Amps of DC Amps

1000 1500 2000 2500 3000 3500

TR-15902 TR-15903 TR-14711 TR-15904 TR-15905 TR-15906

25 25 25

12.5 12.5 12.5

2.29

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GEP387-EN 07/19 Prices and data subject to change without notice.