API TR 11L6-2008 pdf download.Technical Report on Electric Motor Prime Mover for Beam Pumping Unit Service.
1 Scope This technical report covers polyphase, squirrel-cage, induction motors for use as the prime mover for beam pumping units (size range of 200 HP and below). It includes a user Motor Data Sheet (Annex A) and an Electric Motor Performance Data Sheet Request Form (Annex B). Motors to be operated from solid-state or other types of variable frequency/variable voltage power supplies for adjustable speed applications will require individual consideration to provide satisfactory performance and are beyond the scope of this document. 2 Normative References The following reference documents are indispensable for the application of this technical report. For dated references, only the edition cited applies. For undated references, the latest edition of the reference document (including any amendments) applies. ABMA-9 1 , Load Ratings and Fatigue Life for Ball Bearings ABMA-11, Load Ratings and Fatigue Life for Roller Bearings ASTM B117 2 , Standard Practice for Operating Salt Spray (Fog) Apparatus IEEE Std 100 3 , The Authorative Dictionary of IEEE Standards Terms IEEE Std 112, IEEE Standard Test Procedure for Polyphase Induction Motors and Generators IEEE Std 841-1986, Recommended Practice for Chemical Industry Severe Duty Squirrel-Cage Induction Motors— 600V and Below NEDA 12.34.1 4 , Segregation of Losses and Smoothing of Stray-Load Loss NEMA MG 1 5 , Motors and Generators NEMA MG 13-1984, Frame Assignments for Alternating Current Integral Horsepower Induction Motors NEMA MG 13-1956, Frame Assignments for Alternating Current Integral Horsepower Induction Motors (U-Frame Descriptions) NFPA 70 6 , National Electric Code
4.1.3 Size Rating Motors covered by this technical report shall be rated in horsepower (HP) or kilowatt (kw) on a continuous-duty basis. 4.1.4 Synchronous Speed Rating The synchronous speed rating at 60 Hz is 1200 RPM or as specified on the attached Motor Data Sheet (see Annex A). This technical report also permits the motor synchronous speed of 900 RPM or 1000 RPM. 4.1.5 Voltage, Frequency and Phase Ratings Voltage ratings shall be 460/796 or 460 Volts AC, 60 Hertz, 3 Phase or 380V, 50 Hertz, 3 Phase. The 50 Hz synchronous speed is 1000 RPM. 4.1.6 Motor Enclosures Motor enclosures shall be open drip proof (ODP) or totally enclosed fan cooled (TEFC) suitable for unclassified areas. As a minimum, enclosures shall meet ODP—guarded specifications in accordance with NEMA MG 1or TEFC specification in accordance with NEMA MG 1. 4.1.7 NEMA Motor Designs and Starting Characteristics Motors shall be NEMA Design D as specified by NEMA MG 1 with a slip of 5 % to 8 % or ultra-high slip design. Motors shall be capable of accelerating load under conditions as specified in NEMA MG 1. 4.1.8 Frame Assignments Motors furnished in accordance with this technical report, shall as a minimum comply with the frame size assignments as per NEMA MG 13–1984 for T-frame motors or according to NEMA MG 13–1956 for U-frame motors. 4.1.9 Motor Frame Material For cast iron or other materials used, the motor manufacturer shall identify the material used for motor frames, and shields, and other structural parts; corrosion resistant treatment; test for corrosion resistance. 4.1.10 Insulation System (Service Factor, and Temperature Rise) The thermal rating of the insulation system shall be a minimum of Class F as defined in NEMA MG 1. When operated at rated voltage, frequency and load, the temperature rise shall not exceed 80 °C by resistance for Class F insulation, 90 °C by resistance for Class F encapsulated, or 125 °C by resistance for Class H insulation in accordance with IEEE 112.
4.1.13 Bearing Life Bearings shall be selected to provide L-10 rating life of 26,280 hours minimum (3 years continuous) per ABMA-9 or ABMA-11 as applicable. Calculations shall be based on external loads calculated for NEMA bolted application limits in accordance with NEMA MG 1 and internal loads defined by the manufacturer. Regressable bearings shall be provided on frame sizes above 286T. 4.2 Other Electrical Design Considerations 4.2.1 Power Supply Variations 220.127.116.11 Motors shall operate on a continuous basis at rated load with variation in the voltage or the frequency not exceeding the following conditions: a) ± 10 % of rated voltage, with rated frequency; b) ± 5 % of rated frequency, with rated voltage; and c) combination of voltage and frequency variation of 10 % (sum of absolute values) of the rated values, provided that the frequency variation does not exceed ± 5 % of rated frequency.