North American Electric Inverter Duty Motor are suitable for wye-delta start on 213T frame and above. Feet are dual drilled on most frames for mounting flexibility. Cast iron frame construction on 254T frame and above and stainless steel nameplate and zinc plated hardware with corrosion resistant paint finished. Dual voltage ratings 254T and above are suitable for part wind start on lower voltage. Class F insulation system, class B rise at full load, NEMA premium® efficiency. - North American Electric Inverter Duty Motor, Bearing Type: Ball, Construction: Heavy Duty Cast Iron, Duty: Continuous, Enclosure Type: Open Dripproof, Frequency Rating: 50 Hz, Insulation Type: Class F, Mounting Type: F1 Assembly - Foot, Phase: 3-Phase, Rotation: Reversible, Service Factor: 1, Temperature Rating: 40 °C, Voltage Rating: 480V.