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NEMA Standard

NEMA D

NEMA Standard Three-Phase Induction Motor, Design D, for Oil Well Pumps

High starting torque and high slip, for beam pumping units and other loads that need a soft start characteristic rather than a stiff one.

Design DSlip ≥ 5%High starting torque
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NEMA Design D oil well pump motor

NEMA classifies polyphase motors by their torque and slip characteristics into Design A, B, BE, C, CE and D. Design D is the high-starting-torque, high-slip variant: rated slip is 5% or more, which lets the machine absorb the cyclic load swing of a beam pumping unit instead of fighting it.

Frames 250T and above are supplied with grease inlet and drain. The motor is fixed at the non-drive end.

Core specifications

ParameterValue
Frame sizeNEMA T-frames 213T – 449T
Power range3 – 150 HP (2.2 – 110 kW)
DesignNEMA Design D
Rated slip≥ 5%
Breakdown torque275 – 350% of rated (by frame)
Voltage230 / 460 / 796 V
Frequency60 Hz
Service factor1.0 / 1.15
Protection degreeIP54 (IP55)
Insulation classClass F
Ambient / altitude−15 to 40 °C · up to 3,300 ft
CertificationCSA certificate 70060690 (Master Contract 259277) — 6-pole models
Hazardous locationClass I, Division 2, Groups A, B, C, D · T3 (6-pole models, per certificate 70060690)

Standards and certification

  • ANSI/NEMA MG 00001 (MG 1) Design D
  • CSA certificate 70060690

Typical applications

  • Beam pumping units and other oil well pump drives
  • Cyclic loads requiring high breakaway torque and a soft start characteristic

Selection guide

On a beam pumping unit the load swings through every stroke. A stiff Design B motor transmits that swing into the gearbox and the supply; a Design D motor lets speed drop under peak load, which flattens the torque peak. That is why the design exists.
Design D is the established belt-driven answer and the lowest capital cost. Where energy cost dominates, the CYJTYP permanent magnet intelligent drive removes the belt drive entirely and couples to the gearbox input shaft. See the beam pump sizing guide for how to choose between them.

FAQ

Datasheets, dimension drawings and certification copies are issued on request — tell us the rating and we will send the documents for that specific model.

Downloads

DatasheetPDF · 1.1 MBDownload
Installation & maintenance manualInstallation, commissioning and servicingRequest
CertificationCertificates and test reportsRequest

Certificates and test reports are issued against the specific model and rating rather than the series, so we send the ones that apply to your order. Tell us the rating and the market and we will send them.

Related products

CYJTYP Series

Beam pump semi-direct drive

NEMA PE

Premium Efficiency, NEMA MG 1

TYPL Series

Flameproof PM for progressive cavity pumps

Technical articles on this series

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MG 1 is what makes one manufacturer's motor a drop-in for another's. Five things it decides for you — and two IEC systems it carries inside itself.

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Oil Well Pump Motors: Why NEMA Design D Is Specified

A pumping unit asks for torque twice per stroke and gives some back in between. That load shape, not horsepower, is what selects the motor.

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Request a quote — NEMA D

Tell us the rating, quantity and application and an engineer will come back with a specification, the documents for that model, and a price.

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