Integral Horsepower DC Motor & Generator Application Data CA608D

Transcription

1 Integral Horsepower DC Motor & Generator Application Data CA8D

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3 Table of Contents Air Requirements DPSV D-45 Altitude Temperature D-36 Ambient Temperature D-36 Base Variation D-43 Blower Motor Data D-45 Brushes and Commutator D-37 Connections Motor D-41 Connections Generator D-42 Curves - vs. Torque D-11 D-35 Efficiency Data D-38 Electrical Data D-2 D Environment D-39 Heating D-39 Installation Information D-44 Insulation Class Temperature Rating System D-40 Maintenance Information D-44 Momentary Load Capacity D-40 Power Supplies D-43 Radiation D-41 Relubrication Interval D-37 Rotation D-41 Stalled Current Capacity D-38 Thermostats D-44 Unusual Service Conditions D-42 D-43 Variation of Base D-43 Winding Designs Generators D-41 Winding Designs Motors D-41 District Offices Back Cover D-1

4 Application Manual 1AT-259AT Frame 1 Volt Drip-Proof and Totally Enclosed Continuous Duty 1V Drip-Proof Fully Guarded Continuous Duty Data Shown is Calculated and is Not Guaranteed Hp Base RPM Top Rated RPM Frame Size Resistance Ohms at 25 C Comm Field Series Field Circuit Saturated (MH) At Base 0 Volt Shunt Field Data Res Ohms 25'C Unsaturated (Henries) Wk 2 Lb-Ft 2 Static Press (In. of Water) Min. CFM L182AT L182AT L182AT L182AT L186AT L182AT L186AT L186AT L186AT L186AT L186AT L186AT 18AT V Totally Enclosed Non-Ventilated Continuous Duty Data Shown is Calculated and is Not Guaranteed Hp Base RPM Top Rated RPM Frame Size Resistance Ohms at 25 C Comm Field Series Field Circuit Saturated MH) At Base 0 Volt Shunt Field Data Res Ohms 25'C Unsaturated (Henries) Wk 2 Lb-Ft L182AT L182AT L186AT L186AT L186AT L186AT L186AT 18AT AT 258AT 259AT D-2

5 Application Manual 1AT-0AT Frame 240 Volt Drip-Proof, Fully Guarded Continuous Duty Hp 1 1-1/ /2 15 Base RPM Top Rated RPM Data Shown is Calculated and is Not Guaranteed Resistance Ohms at 25 C Circuit Saturated (MH) 240 Volt Shunt Field Data 0 Volt Shunt Field Data At Base Res Ohms 25'C Unsaturated (Henries) At Base Res Ohms 25'C Unsaturated (Henries) Frame Size Comm Field Series Field Wk 2 Lb-Ft L182AT L182AT AT L182AT L182AT L182AT L186AT L186AT L182AT L182AT L182AT L186AT L186AT L182AT L182AT L186AT L186AT AT AT AT L186AT L186AT L186AT AT OAT AT AT L186AT L186AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT D-3

6 Application Manual 1AT-0AT Frame 240 Volt Drip-Proof, Fully Guarded Continuous Duty Hp 25 D-4 Base RPM Top Rated RPM Data Shown is Calculated and is Not Guaranteed Resistance Ohms at 25 C Circuit Saturated (MH) 240 Volt Shunt Field Data 0 Volt Shunt Field Data At Base Res Ohms 25'C Unsaturated (Henries) At Base Res Ohms 25'C Unsaturated (Henries) Frame Size Comm Field Series Field Wk 2 Lb-Ft 2 258AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT L407AT AT AT AT L409AT AT AT AT AT

7 Application Manual - 1AT-0AT Frame - 0 Volt Drip-Proof, Fully Guarded Continuous Duty Hp / Base RPM Top Rated RPM Frame Size Resistance Ohms at 25 C Comm Field Series Field Circuit Saturated (MH) 240 Volt Shunt Field Data 0 Volt Shunt Field Data At Base Res Ohms 25'C Unsaturated (Henries) At Base Res Ohms 25'C Unsaturated (Henries) L186AT L186AT L186AT L186AT L186AT L186AT AT L186AT L186AT AT AT AT AT OAT AT AT AT AT AT AT AT AT AT AT : AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT Wk 2 Lb-Ft 2 D-5

8 Application Manual 1AT-0AT Frame 0 Volt Drip-Proof, Fully Guarded Continuous Duty Hp Base RPM Top Rated RPM Frame Size Resistance Ohms at 25 C Comm Field Series Field Circuit Saturated (MH) 240 Volt Shunt Field Data 0 Volt Shunt Field Data At Base Res Ohms 25'C Unsaturated (Henries) At Base Res Ohms 25'C Unsaturated (Henries) AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT AT OAT Wk 2 Lb-Ft 2 D-6

9 Application Manual 1AT-0AT Frame 240 Volt Totally Enclosed Continuous Duty Hp /2 15 Base RPM Top Rated RPM Resistance Ohms at 25 C Circuit Saturated (MH) 240 Volt Shunt Field Data 0 Volt Shunt Field Data At Base Res Ohms 25'C Unsaturated (Henries) At Base Res Ohms 25'C Unsaturated (Henries) Frame Size Comm Field Series Field Wk 2 Lb-Ft L182AT NV L182AT NV 8 10 L186AT NV AT NV AT NV 38 L182AT NV L182AT NV L186AT NV L186AT NV AT NV AT NV AT NV L186AT NV L186AT NV L186AT NV AT NV AT NV OAT NV AT NV L186AT NV L186AT NV L186AT NV AT FC AT NV AT NV AT NV 38 L186AT NV L186AT FC OAT FC AT NV AT NV AT NV AT FC 38 L186AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC D-7

10 Application Manual 1AT-0AT Frame 240 Volt Totally Enclosed Continuous Duty Hp Base RPM Top Rated RPM Frame Size Resistance Ohms at 25 C Comm Field Series Field Circuit Saturated (MH) 240 Volt Shunt Field Data 0 Volt Shunt Field Data At Base Res Ohms 25'C Unsaturated (Henries) At Base Res Ohms 25'C Unsaturated (Henries) AT NV AT FC AT FC AT FC AT FC AT FC AT FC AT NV AT FC AT FC AT FC AT FC AT FC AT UC AT FC AT FC AT FC AT FC AT UC AT UC AT FC AT FC AT FC AT FC AT UC AT UC AT FC AT FC AT UC AT UC AT UC AT FC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC L407AT UC AT UC AT UC L409AT UC AT UC AT UC AT UC AT UC Wk 2 Lb-Ft 2 D-8

11 Application Manual 1AT-0AT Frame 0 Volt Totally Enclosed Continuous Duty Hp / Base RPM Top Rated RPM Frame Size Resistance Ohms at 25 C Comm Field Series Field Circuit Saturated (MH) 240 Volt Shunt Field Data 0 Volt Shunt Field Data At Base Res Ohms 25'C Unsaturated (Henries) At Base Res Ohms 25'C Unsaturated (Henries) L186AT NV L186AT NV AT NV AT NV L186AT NV L186AT NV AT NV AT NV L186AT FC AT FC AT NV AT FC AT FC AT FC OAT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT FC AT UC AT FC AT FC AT FC AT FC AT UC AT UC Wk 2 Lb-Ft 2 D-9

12 Application Manual 1AT-0AT Frame 0 Volt Totally Enclosed Continuous Duty Hp Base RPM Top Rated RPM Frame Size Resistance Ohms at 25 C Comm Field Series Field Circuit Saturated (MH) 240 Volt Shunt Field Data 0 Volt Shunt Field Data At Base Res Ohms 25'C Unsaturated (Henries) At Base Res Ohms 25'C Unsaturated (Henries) AT FC AT FC AT FC AT FC AT UC AT UC AT FC AT FC AT UC AT UC AT UC AT FC AT UC AT UC AT UC AT UC AT FC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC AT UC Wk 2 Lb-Ft 2 D-

13 Maximum Continuous vs Torque SPEED VS. CONTINUOUS TORQUE CURVES The motors on catalog page A-2 are capable of operating continuously over a :1 constant torque speed range. The motors on pages A-3 through A-25, however, are listed for continuous rated torque at base speed only. For operation below base speed, the curves on the following pages must be consulted. The catalog pages 12 through 35 show speed vs. maximum continuous torque and are grouped by frame size, enclosure and base speed. Each page has curves for several NEMA designated power supply types. The NEMA power supply types are described on page 46. The designations A through K are in order of increasing AC ripple content relative the average DC component. The DC component produces useful torque from the motor, while the AC component generates losses in the form of heat. An internal shaft mounted fan plus armature generated turbulence aids in the dissipation of heat. The effects of both of these are decreased when speed is reduced. The lower heat dissipation capacity at reduced speeds results in lower armature current capacity and therefore lower torque. The curves indicate the effects of this and of the power supply type. The solid curves are for class F temperature rise. The standard motor is rated for class F rise; the windings are class H, but the lead wire is class F. The dashed curves are for class H rise. A full Class H system is available as an option. As an example, suppose we would like to know the continuous constant torque speed range for a standard 15 Hp motor with abase speed of 17 RPM, in a drip proof fully guarded enclosure with a 0V armature operated on a NEMA D power supply. From page A-4, we see that this rating is in a 258AT frame. Page 14 has the family of curves that apply to this rating. The solid NEMA D power supply curve crosses the vertical % rated torque gridline at 79% of base speed. The motor can be operated continuously at rated torque on this power supply down to 1383 RPM with standard class F temperature rise. If only % of rated torque is required, the motor may be operated down to 8 RPM. If additional torque is required below base speed, you may choose to add a blower to the motor making the enclosure drip proof blower vented. The effect of this additional cooling to this 15 Hp motor is shown on page D-19. If even more low speed torque is required, a Hp motor may need to be used. D-11

14 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES L182AT, L186AT, 18AT MOTOR FRAMES SELF-VENTILATED MOTORS RATED SPEEDS: 17, 11 AND 8 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. 17 RPM D* C K, *K K, *K A Percent of Base Percent of Rated Torque or ature Current *Without Free-Wheeling Rectifiers D-12

15 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES SELF-VENTILATED MOTORS RATED SPEEDS: 6, 0, 400 AND 0 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E Percent Base 40 A D C Percent of Rated Torque or ature Current D-13

16 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES SELF-VENTILATED MOTORS RATED SPEEDS: 17, 11 AND 8 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D A E D A Percent of Base Percent of Rated Torque or ature Current D-14

17 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES SELF-VENTILATED MOTORS RATED SPEEDS: 20 AND RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D A E D A Percent of Base Percent of Rated Torque or ature Current D-15

18 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 3AT - 0AT MOTOR FRAMES SELF-VENTILATED MOTORS RATED SPEEDS: 8 RPM AND BELOW Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. D C A D C A Percent of Base Percent of Rated Torque or ature Current D-16

19 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 3AT - 0AT MOTOR FRAMES SELF-VENTILATED MOTORS RATED SPEEDS: 17 AND 11 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. D C A D C A Percent of Base Percent of Rated Torque or ature Current D-17

20 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES BLOWER VENTILATED AND SEPARATELY VENTILATED MOTORS RATED SPEEDS: 6, 0, 400, 0 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D A E D A Percent of Base Percent of Rated Torque or ature Current D-18

21 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES BLOWER VENTILATED AND SEPARATELY VENTILATED MOTORS RATED SPEEDS: 17, 11 AND 8 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D A E D A Percent of Base Percent of Rated Torque or ature Current D-19

22 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES BLOWER VENTILATED AND SEPARATELY VENTILATED MOTORS RATED SPEEDS: 20 AND RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D A E D A Percent Base Percent of Rated Torque or ature Current D-

23 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 3AT, 400AT, 0AT MOTOR FRAMES BLOWER VENTILATED AND SEPARATELY VENTILATED MOTORS RATED SPEEDS: 6 RPM AND BELOW Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. C A C A Percent of Base Percent of Rated Torque or ature Current D-21

24 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 3AT MOTOR FRAMES BLOWER VENTILATED AND SEPARATELY VENTILATED MOTORS RATED SPEEDS: 17, 11, AND 8 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. D C A D C A Percent of Base Percent of Rated Torque or ature Current D-22

25 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 400AT - 0AT MOTOR FRAMES BLOWER VENTILATED AND SEPARATELY VENTILATED MOTORS RATED SPEEDS: 17, 11, AND 8 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. D C A D C A Percent of Base Percent of Rated Torque or ature Current D-23

26 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 218AT, 219AT, 21AT MOTOR FRAMES TOTALLY ENCLOSED NON-VENTILATED MOTORS RATED SPEEDS: 0, 400 AND 0 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D A E D A Percent OF Base Percent of Rated Torque or ature Current D-24

27 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 218AT, 219AT, 21AT MOTOR FRAMES TOTALLY ENCLOSED NON-VENTILATED MOTORS RATED SPEEDS: 11, 8 AND 6 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D E A D A Percent of Base Percent of Rated Torque or ature Current D-25

28 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 218AT, 219AT, 21AT MOTOR FRAMES TOTALLY ENCLOSED NON-VENTILATED MOTORS RATED SPEEDS: 17, 20 and RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E E D A D A Percent of Base Percent of Rated Torque or ature Current D-26

29 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES TOTALLY ENCLOSED FAN-COOLED MOTORS RATED SPEEDS: 6, 0, 400 AND 0 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D A E D A Percent of Base Percent of Rated Torque or ature Current D-27

30 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES TOTALLY ENCLOSED FAN-COOLED MOTORS RATED SPEEDS: 17, 11 and 8 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D E A D A Percent of Base Percent of Rated Torque or ature Current D-28

31 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 2AT - 3AT MOTOR FRAMES TOTALLY ENCLOSED FAN-COOLED MOTORS RATED SPEEDS: 20 and RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. E D E A D A Percent of Base Percent of Rated Torque or ature Current D-29

32 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 3AT - 400AT MOTOR FRAMES TOTALLY ENCLOSED FAN-COOLED MOTORS RATED SPEEDS: 6, 0, 400 and 0 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. D C A D CA Percent of Base Percent of Rated Torque or ature Current D-

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34 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 3AT, 400AT MOTOR FRAMES AIR-OVER-FRAME COOLED MOTORS RATED SPEEDS: 6, 0, 400 and 0 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. D C A D C A Percent of Base Percent of Rated Torque or ature Current D-32

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36 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 400AT-0AT MOTOR FRAMES TOTALLY ENCLOSED UNIT-COOLED MOTORS RATED SPEEDS: 6, 0, 400 and 0 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. Percent of Base 40 A A C D D C Percent of Rated Torque or ature Current D-34

37 Maximum Continuous vs Torque CALCULATED DATA SHOWN ARE APPROXIMATE VALUES AND DO NOT CONSTITUTE GUARANTEES 400AT-0AT MOTOR FRAMES TOTALLY ENCLOSED UNIT-COOLED MOTORS RATED SPEEDS: 17, 11 and 8 RPM Max. Temp. Rise (Class H Rise) Class F Temp. Rise NOTE: See application engineering sheets on pages D-11 and D-46 before using these curves. D C A D C A Percent of Base Percent of Rated Torque or ature Current D-35

38 Maximum Continuous vs Torque AMBIENT TEMPERATURE The ambient temperature rerating on standard DC electric motors can be estimated by the use of the curve shown in Fig FIG. 1 The standard ratings are in accordance with NEMA MG for a maximum ambient temperature of 40 C. The percentage of rated load can also be estimated with the above curve. It should be noted that to maintain safe temperatures in the field windings, the shunt field voltage and current rating must also be derated by the use of the same curve. Bearing grease is another consideration for wideambient temperature excursions. Standard Baldor motors are lubricated with a highquality grease that has a temperature range of - C to 175 C. Prolonged operation at temperatures below 0 C should be referred to Baldor's application Engineering. Special considerations must be made for carbon brush material, casting and shaft metallurgy. A wide-ambient temperature excursion in a short period of time could result in excessive condensation inside the machine during idle periods. Consideration should be given to the use of space heaters and/or "field economy" heating of the motor during these idle periods. Proper consideration must also be given to the protection of a motor which is subjected to both high and low ambient temperatures. The use of an internal thermal switch plus the use of control heaters must be carefully selected. % Rated Load 0 40 Ambient Temperature C When a standard DC motor is intended for use at altitudes in excess of one Kilometer (30 feet), it must be derated as indicated by the derating curve in Fig. 2. To use Fig. 2, first make any derating adjustments for ambient temperatures as outlined. Then apply % load curve to further derate the machine for altitude. Similar adjustments must be made to the Shunt Field voltage and current to maintain safe operating temperatures in the Shunt Field windings. Use right hand scale for this purpose. ALTITUDE TEMPERATURE Carbon brushes and machine commutation can be seriously affected by high altitudes. Proper consideration for carbon brushes should be referred to Baldor. % Load FIG Altitude Feet % Shunt Field Voltage or Current D-36

39 Application 4.0 RELUBRICATION INTERVAL Baldor motors are lubricated as standard with Chevron "SRI" grease. Based on a limited military spec, test program, Chevron SRI grease has attained grease life s of over 4.5 times sodium and sodium synthetic greases, and times lithium base greases. The relubrication intervals suggested in Fig. No. 5 are conservative with respect to the Chevron grease and can be exceeded in many applications. Baldor's field experience shows that Chevron SRI far out performs most other greases in longevity. FIG. 5 Hours Ball Bearings Roller Bearings Frame CHEVRON SRI GREASE RELUBRICATION INTERVAL BRUSHES AND COMMUTATOR Because the brushes and commutator are wearing parts, the life expectancy varies greatly under different operating conditions. See BEC-5 for further information. Listed below are a few conditions that cause abnormal brush and commutator wear: (1) Contaminated atmosphere: (a) Chemical gases - such as alkali or acid. (b) Dust - abrasive, conductive, or both. (c) Low humidity. (d) Oil vapor. (2) Light loading - defined as % of rated for long periods. Applications that typically have one or more of the conditions listed above are: (1) Blast furnaces (6) Paper mills (2) Cement mills (7) Power plants (3) Chemical plants (8) Steel mills (4) Electrolytic process plants (9) Transit or Railway applications (5) Mines D-37

40 Application STALLED-CURRENT CAPACITY The maximum continuous speed versus torque curves indicate the thermal limits of the motor. The curves do not show operation below 5% of base speed. At zero speed, localized heating occurs in the commutator bars. This heating may cause distortion of the commutator bars resulting in excessive brush wear and vibration. The maximum percent of the rated armature current zero (0) speed must be limited as shown below in Table 3. Time at Zero (0) TABLE 3 Percent (%) of Rated ature Amperes 1AT - 0 AT DPFG TE sec. 0% 400% sec. 0% 2% 1 min. 1% 1% 2 min. % 1% 5 min. 64% % min. % 62% min. 40% % Cont. % 40% FIG. 6 TYPICAL FULL LOAD EFFICIENCY DATA FULL LOAD EFFICIENCIES OF CATALOGUED STANDARD D.C. MOTORS OPERATING AT 17 RPM FULL LOAD EFFICIENCIES OF CATALOGUED STANDARD D.C. GENERATORS OPERATING AT 17 RPM Horsepower Input Kilowatt Output % Efficiencies 40 % Efficiencies D-38

41 Application ENVIRONMENT The standard insulation system in Baldor D.C. motors is adequate for use in humid atmospheres. Special consideration is required when abrasive dust, acids, alkalies, conductive dust, etc., are present. These conditions impose a severe hardship on drip-proof full-guarded D-C motors. Contamination may cause shorting or grounding circuits over the insulation, thus causing a creepage path which may eventually lead to electrical failure, regardless of the insulation system. When contamination is known to exist, a study should be made to determine what types of motor enclosures have been successful in the past. Although, in many cases, a drip-proof full-guarded machine is adequate, extra reliability would be provided by a totallyenclosed machine. HEATING Motor Operation Using Hertz Power Supply For motor operation on Hertz power supply, reduce the rated Hertz torque or armature current by 5%. The operating performance on Hertz power can be made equal to that on Hertz power by increasing the total armature circuit inductance by %. Maximum Continuous vs. Torque Curves When using power supplies type C, D or E, curves are applicable for AC source voltages to a maximum of 3% of rated (2V or 4V). For source voltages within the range of 3 to 1% of rated, reduce armature current 2%. For power supply definitions, see page D-46. Overvoltage Using Rectifier Source Motors in the frame size range of 21 OAT to 0AT are capable of operation at 1% of rated DC armature voltage at speed and torque values of 1% of rated, where the AC source voltage is limited to 3% of rated source voltage (2V or 4V). When top-rated speed by field control is not exceeded voltage source limits for various frame sizes are as follows: (a) Motor frame size range 2AT-0AT rated for 0V and 5V may be operated up to 1% of rated voltage, 1% of rated speed or 0V RMS supplied to the power supply rectifiers (0V peak) whichever limit occurs first. (b) Motor frame sizes 1AT rated 0V and 5V are not recommended for overvoltage operation. Limit the applied voltage to rated 4V RMS supplied to the power supply rectifiers (6V peak). Due to the increased phase back required, standard design motors, which obtain power from rectified power supplies with previously listed peak voltages, may not meet rated temperature rise at base speed. Therefore, when motor operation at voltages greater than 253V RMS for 240V motors or 6V RMS for 0-5V motors is desired, contact Baldor. DC Motor Field Heating Many applications require the shunt fields to be energized in a stand-by condition with the armature at standstill. Standard continuous duty motors may be operated at rated field voltage in this manner with the shunt field operating within safe temperature limits. This temperature limit will exceed the rise at rated load/speed. This may result in insulation life shorter than the standard design insulation life which is based on operation at rated load/ speed. Longer insulation life will result if field economy relays are used. Also, a field economy relay is recommended for stand-by operation whenever the field excitation voltage exceeds 3% of rated. Standard continuous duty self-ventilated motors are suitable for rated load/speed operation at full excitation voltage up to 1% of rated; however, insulation life may be reduced during prolonged operation at low speeds. Consult the curves on page D-43, Fig. 7 for expected insulation life under various operation conditions. CAUTION: When the motor is shut down for holidays, over night or weekends, the fields must either be shut off or a field economy circuit must be used. This is because the AC line voltage usually rises, thus causing higher field voltage. Short-time-rated motors must have the fields de-energized when the armature circuit is not energized. Variation in speed from full bad cold to full load hot should not be more than 15% for ventilated motors and % for totally enclosed motors. D-39