The 1326AB-B720E-21-L is a three-phase brushless AC permanent magnet synchronous servo motor from Reliance, also branded under Allen-Bradley and Rockwell Automation. It belongs to the 1326AB Torque Plus series, featuring medium-low inertia and high torque density for high-speed and heavy-load motion control. This model adopts totally enclosed non-ventilated structure and upgraded IP67 protection grade for reliable operation in harsh industrial environments. It is a discontinued legacy product, and refurbished and used units are commonly supplied for equipment maintenance and replacement.

1326AB represents the high-performance AC servo motor series. B refers to the motor frame size. 720 stands for power rating and core stack length with rated power of 6.8 kW. E indicates the maximum speed specification, reaching 3500 revolutions per minute under 460 VAC. 21 means the motor uses standard IEC metric flange and metric keyway shaft for installation. L stands for enhanced protection design with IP67 rating.

This servo motor is designed for three-phase 380 VAC to 460 VAC power supply at 50 Hz and 60 Hz. The rated speed is 3000 revolutions per minute at 380 VAC and 3500 revolutions per minute at 460 VAC. Its rated torque is 30.9 N·m, and the continuous stall torque remains 30.9 N·m at zero speed. The peak stall torque is 88.1 N·m, and the rotor inertia is 0.015 kg·m². It uses brushless resolver as the standard feedback component. The motor winding is Class F insulation which can withstand temperature up to 155 degrees Celsius. The overall protection grade is IP67, and the motor is built with totally enclosed non-ventilated aluminum housing. The applicable ambient temperature ranges from 0 degrees Celsius to 40 degrees Celsius. The total weight is approximately 58 kilograms.

A top-mounted junction box is equipped for connecting three-phase power cables and grounding wire. A dedicated connector is reserved for the resolver to transmit position, commutation and speed feedback signals. The mechanical interface adopts IEC metric flange and keyway shaft to connect with mechanical loads. This motor is fully compatible with Allen-Bradley 1394, Ultra and Kinetix series servo drives. There is no independent external communication port, and all control signals and data transmission are completed through the matched servo drive. All wiring ports are equipped with anti-interference design to adapt to complex industrial electromagnetic conditions.

It delivers high continuous torque and power output, suitable for combined working conditions of high speed and heavy load. The medium-low inertia structure ensures fast acceleration and deceleration as well as high positioning accuracy. The brushless resolver features strong resistance to vibration and high temperature, maintaining stable signal feedback during long-term operation. The IP67 protection structure effectively prevents dust and water ingress to protect internal components. A built-in thermal protection device will trigger protection when overheating occurs to avoid damage to motor windings. Optimized stator winding reduces torque ripple and ensures smooth operation at low speed.

It is widely applied on high-speed CNC machine tools including milling machines, lathes and grinders for heavy cutting and rapid feeding. It serves high-speed packaging equipment, material handling systems and automated assembly lines with dynamic loads. It is also used for metal forming equipment such as stamping and bending machines that require high torque and frequent start and stop. Additionally, it works for production lines in automobile manufacturing industry. It is an ideal replacement part for upgrading and maintaining legacy servo systems, and can operate stably in workshops with dust, moisture and slight vibration.

Cut off all power before installation. Mount the motor firmly on a rigid surface and reserve enough space around for heat dissipation. Connect power cables and feedback cables in accordance with terminal definitions and complete reliable grounding. Use flexible coupling to connect the motor shaft and load to avoid shaft misalignment. Set corresponding parameters on the supporting servo drive according to motor specifications. After full inspection, power on the system, perform jog test to check rotation direction, then start formal operation.

Carry out routine inspection every three to six months to check motor housing, flange, cables and connectors for damage and wear. Cut off power before cleaning, and wipe the motor and junction box with dry cloth. Retighten all wiring terminals every year to prevent loose connection. Regularly inspect resolver connectors and signal lines to ensure stable signal transmission. The motor uses sealed bearings which require no regular lubrication. Replace the bearings in time if abnormal noise or excessive vibration appears. Store spare motors in cool, dry and dust-free environment. Do not disassemble the motor without authorization, and all maintenance and repair work must be handled by professional technicians.