Marathon U351A (model 256TTFL16004) is a 20 HP, 3600 RPM three-phase JM pump motor with a NEMA 256JM frame and Totally Enclosed Fan Cooled enclosure. It operates on 230/460V at 60 Hz with a 1.15 service factor. This close-coupled pump motor is designed for centrifugal pump applications requiring C-face mounting with threaded shaft.

Marathon® AC Motor, 2-Pole Continuous Duty, Jet Pump (JM/JP) Motors Application, Inverter Ready Special Features, 20 hp, 230/460 VAC, 47/23.4 A, 60 Hz Frequency, 3 ph, 3537 rpm Speed, 1 Speed, Totally Enclosed Fan Cooled (TEFC) Enclosure, 256JM Frame, 1-1/4 in Dia x 5-1/4 in L Shaft, Reversible Rotation, 1.15 Service Factor, Ball Bearing, 37.5 ft-lb Torque, Rigid Base Mounting, 40 deg C, Insulation Class: Class F, Aluminum, 2:1 Constant Torque Speed, 10:1 Variable Torque Speed, 27.27 in L x 17.11 in W x 14.43 in H

Features:

• Ball bearings mechanically locked on shaft end
• NEMA JM pump shaft dimensions
• JM frame has rigid base, drip cover not included
• Standard assembly F1 and reversible to F2 assembly
• IP55 rating, enclosure protection against dust and water jets
• Hazardous Duty™ motors division 2 UL certification nameplate
• Division 2/zone 2 class 1 (gases), groups A, B, C, D
• Horizontal motor orientation
• Squirrel cage induction run

Specs:

• Variable Torque Speed Range: 10:1
• Constant Torque Speed Range: 2:1
• Service Factor: 1.15
• Special Features: Inverter Ready
• Application Type: Jet Pump (JM/JP) Motors
• Insulation Class: Class F
• Shaft Size: 1-1/4 in Dia x 5-1/4 in L
• Torque Rating: 37.5 ft-lb
• Phase: 3 ph
• Horsepower: 20 hp
• Number of Speeds: 1
• Rotation: Reversible
• Frame: 256JM
• Bearing Type: Ball
• Temperature Rating: 40 deg C
• Enclosure Type: Totally Enclosed Fan Cooled (TEFC)
• Speed: 3537 rpm
• Frequency Rating: 60 Hz
• Mounting Type: Rigid Base
• Amperage Rating: 47/23.4 A
• Voltage Rating: 230/460 VAC
• Dimensions: 27.27 in L x 17.11 in W x 14.43 in H
• Material: Aluminum
• Type: 2-Pole Continuous Duty