Atlas Copco 1091634104 AT160M1-201 15 kW Drive Motor

Role in the Compressor Package

The 1091634104 converts electrical energy into shaft torque for the compressor airend. In an oil-injected screw machine, the drive motor is the largest single energy consumer. Its output defines the available air delivery and the overall efficiency of the package. A correctly matched motor keeps the compressor on its designed flow and pressure curve.

The AT160M1-201 Designation

The AT160M1-201 model identifies the motor's frame and electrical configuration. The 160M portion denotes an IEC 160M frame size suited to the 15 kW power class. That frame provides the mass and thermal capacity needed for sustained industrial duty. Atlas Copco specifies this motor for integration into GA-class fixed-speed compressor packages, where the shaft couples directly to the airend.

Electrical Nameplate Data

Mechanical and Environmental Data

Reading the Nameplate Values

The 2940 r/min full-load speed at 50 Hz confirms a 2-pole design. A 2-pole machine runs at a 3000 r/min synchronous speed on 50 Hz power. The 60 r/min difference is slip, and slip generates the torque. A 0.913 power factor shows efficient reactive-power behavior. The 26 A nameplate rating determines contactor and cable sizing in the compressor electrical panel. The IP54 rating blocks harmful dust and resists splashing water from any direction. Class F insulation permits a 155°C winding limit, adding thermal margin above Class B. These ratings suit the oil mist and warmth inside a compressor canopy.

From Stator Field to Shaft Rotation

When 400 V three-phase power at 50 Hz reaches the stator windings, a rotating magnetic field appears. A 2-pole winding turns that field at 3000 r/min. The field induces current in the rotor bars through electromagnetic induction. This induced current creates a rotor magnetic field that interacts with the stator field and produces torque. The squirrel-cage rotor has no brushes or slip rings, so it needs little maintenance. Low rotor loss at 2% slip keeps the motor efficient across long running hours.

The rotor never reaches synchronous speed. It settles at 2940 r/min under full load, about 2% slip. Without that slip, no current would be induced and no torque would form. Low slip indicates an efficient rotor design with minimal copper loss.

Delta Connection and Starting Current

The nameplate specifies a delta (Δ) winding for 400 V operation. Delta connection places the full line voltage across each phase winding. The 31.2 × starting-current ratio means a brief inrush near 811 A at switch-on (26 A × 31.2). That surge demands correctly sized contactors and starter protection. Long supply cables should be checked for voltage drop during starting.

Compressor Classes Served

The 1091634104 carries nameplate values of 15 kW, 400 V, and 50 Hz. These match the drive specification of the GA15 family of fixed-speed oil-injected screw compressors. Equivalent 15 kW GA-class units use the same power and voltage platform. The motor also fits compatible GX-class 15 kW packages built on the same electrical standard.

Always verify fitment against the compressor serial number and the existing motor nameplate before ordering. Compressor variants by year or region may use a different drive motor. The part number on the original nameplate is the only reliable match key.

Mechanical Interface

This motor couples directly to the compressor airend through the shaft extension. The IEC 160M frame defines the foot and flange dimensions for that coupling. Precise shaft diameter and keyway geometry protect the airend bearings from misalignment loads. Using a motor with the correct frame and shaft data prevents premature drivetrain wear.

Replacement Considerations

The 1091634104 weighs 125 kg and requires suitable lifting gear during replacement. Isolate the electrical supply and confirm isolation with a voltage tester before work begins. Drain the compressor oil if the coupling interface requires access. Run the motor briefly unloaded to confirm rotation direction before final coupling.

Monitoring for Long Service Life

The rotor bearings are the primary wear components at 2940 r/min. Monitor vibration at the bearing housings on a regular schedule. Track running current against the 26 A nameplate value under steady load. A rising current trend at constant output signals developing inefficiency. Periodic insulation resistance checks protect the Class F windings from moisture and heat aging.