OMHT-Srs-Bipolar-Step-Motors

Supported Applications

The Omega OMHT Series comprises a robust line of 2-phase bipolar step motors designed for motion control applications requiring precise position control. These motors conform to industry-standard NEMA mounting dimensions, ranging from frame size NEMA 11 through NEMA 34. The series is engineered for use with compatible drives and indexers. Motors can be operated in a closed-loop system utilizing incremental encoders.

Operating Conditions & Performance

The OMHT Series delivers high torque performance, with holding torques reaching up to 1845 oz-in depending on the model and connection type. Most models are optimized for microstepping; except for the two smallest motors (OMHT11-013, OM5014-842), all motors achieve resolutions of up to 51,200 steps/revolution (0.007° per step) when paired with microstepping drives.

Operational limits and mechanical specifications include:

• Operating Temperature Range: -20 to 50°C (-4 to 122°F)
• Insulation Class: 130°C (266°F) Class B
• Mechanical Tolerances: Shaft run-out varies by size from 0.01 mm (0.0005 inch) for sizes 11 through HT17 to 0.05 mm (0.002 inch) for sizes 23, HT23, and 34.
• Load Capacities: Maximum radial loads range from 2268 g (5 lb) for smaller frames up to 11340 g (25 lb) for NEMA 34. Maximum thrust loads extend from 1361 g (3 lb) on size 17 motors to 22680 g (50 lb) on NEMA 34.

Guaranteed minimum holding torque is specified; actual torque may be 5 to 10% greater. Lead wire gauges vary by frame, ranging from 26 AWG for sizes 11 and HT17 down to 18 AWG for size 34.

Configuration Options

The series offers extensive configuration options across mounting styles, electrical connections, and shaft types. All motors are offered with compatible drives and indexers as detailed in the optimal drive/motor combinations table.

• Frame Sizes: NEMA 11, 14, 17 (including HT17), 23 (including HT23), 24, and 34 (including HT34).
• Shaft Configurations: Standard single shaft models are available. Double shaft versions can be ordered by adding the suffix “-D” to the model number.
• Cable Options: Motors with a 3 m (10') shielded cable are offered as an option.
• Electrical Connections:
  • 8-Lead Motors: Support both series and parallel connections. Series connection is recommended for best torque at low speeds; parallel connection provides best torque at higher speeds.
  • 4-Lead Motors: Available on select models with fixed wiring (Drive A+ = Red, Drive A- = Blue, Drive B+ = Yellow, Drive B- = White).
• Wiring Details for 8-Lead Motors:
  • Parallel Connection: Drive A+ = Orange + Black/White; Drive A- = Black + Orange/White; Drive B+ = Red + Yellow/White; Drive B- = Yellow + Red/White.
  • Series Connection: Drive A+ = Orange; Drive A- = Black; Drive B+ = Red; Drive B- = Yellow. Connect Orange/White to Black/White (not connected to drive); connect Red/White to Yellow/White (not connected to drive).

Key Product Differences

Variants within the OMHT Series are distinguished by frame size, motor length, holding torque ratings, and electrical parameters. Specific model numbers define these variations:

• NEMA 34 High Torque Models: Examples include OMHT34-487 (156 mm / 6.14 inch length) with a maximum holding torque of 1845 oz-in in series connection, and OMHT34-490 offering similar dimensions.
• NEMA 23 Models: Variants such as OMHT23-393 and OMHT23-603 provide different length-to-torque ratios suitable for mid-range applications.
• <small>Note: Model numbers listed in the series documentation are for single shaft configurations. Double shaft variants require the “-D” suffix (e.g., OMHT23-393-D).</small>