Service conditions - Unless otherwise specified, motors conforming to this specification shall be suitable for operation in accordance with their rating under the following service conditions:

Ambient temperature in a range of -40C to 40C (-40F to 104F).

Maximum altitude of 1000 meters (3300 feet) above sea level.

Indoor or outdoor installations in hostile duty applications.

Variable Frequency Drive (VFD) or Full voltage, across-the-line starting.

Standards - All motors shall be in accordance with NEMA Standard MG1-1993, or the latest revision in so far as it is applicable. Motors shall also comply with the applicable portions of the 1997 National Electric Code, the Canadian Standards Association, and the Energy Policy Act of 1992.

Electrical Requirements

Voltage and Frequency

Standard motors shall be dual voltage through 405 frame and single voltage 444 frame and above. Motors will be rated for operation on 3 phase, VFD power supply.

Motors shall operate successfully under running conditions at rated load with variation in the voltage or the frequency not exceeding the following conditions:

+/-10% rated voltage at rated constant volts/hertz ratio except for specific torque boost situations.

Motors shall operate successfully under running conditions at rated load and volts/hertz ratio when the voltage unbalance at the motor terminals does not exceed one percent.

Operating Characteristics - With rated volts/hertz ratio applied, motor performance shall be as follows for critical operating characteristics:

Torques - Motors shall meet or exceed the minimum locked rotor (starting) and breakdown torques specified in NEMA Standard MG1 Part 12 for Design B for the rating specified when on sine wave power.

Currents - Locked rotor (starting) currents shall not exceed NEMA Design B values for the specified rating on 5:1 constant torque or less and variable torque motors. NEMA Design A values are allowed for 6:1 constant torque or higher value constant torque rated motors. Motors shall be capable of a 20 second stall at six times full load current without injurious heating to motor components.

Efficiency - Motors 600 volts and below shall have a nameplate minimum and nominal full load efficiency which will meet or exceed the values listed in Table 1 for motors when tested in accordance with NEMA standard MG1 Part 12, IEEE Test Procedure 112 Method B, using accuracy improvement by segregated loss determination including stray load loss measurements.

Temperature Rise - The temperature rise, by resistance, shall be 80 degrees C or less when measured at rated load on sine wave power, on inverter power ratings shall be 105 degrees C or less.

Service Factor and Ambient - Standard motors shall be rated for a 1.15 service factor on sine wave power and 1.0 service factor on VFD power in a 40C ambient.

Insulation

Standard motors shall utilize the US Electrical Motors Inverter Grade insulation system which consists of at a minimum Class F or better insulation materials with additional phase insulating material, extra end-turn bracing and Class H spike resistant wire. The resultant system shall withstand 2000 volt transients without premature motor failure and have no cable limitations in motor application.

Standard motors shall be given US Electrical Motors Insulife 2000 an additional insulation treatment to increase moisture resistance.

Mechanical Requirements

Frame Size

The horsepower to frame relationship shall conform to the latest NEMA MG 13 Standard for T frame motors for frames 143 - 447 frames. 10:1 constant torque speed range motors may exceed frame standard by one frame rating.

All motors 600 volts and below 182 - 447 frame shall be capable of field modification of NEMA F1 to F2 mounting assembly.

Motors covered by this specification are 143 - 447 frame sizes.

Enclosure

Motors shall be totally enclosed fan cooled (TEFC) or totally enclosed non-ventilated (TENV) construction and convertible for severe environments.

Motor frame, endshields and inner bearing caps shall be cast iron construction. Conduit box and Fan Cover may be of steel construction but with field modifiable kits for cast iron fan cover and conduit box on 182-447 frames.

Bearings

All motors 250 frame and above shall have fully re-greasable, anti-friction bearings. 140 frame shall be sealed and lubed for life, 180-360 frame shall be double shielded and 400-440 frame bearings will be open..

All motors 182 frame and above shall have cast iron inner bearing caps.

All motors shall have a charged lubrication system to inhibit moisture condensation.

Standard motors in frames 254-447 shall have extended grease fittings on the opposite drive-end to facilitate re-lubrication. Grease ports shall be located on the periphery of the motor endshield.

Motor shall be fitted with a shaft slinger for a minimum of IP-54 protection.

Ventilating Fans - shall be corrosion resistant, non-sparking material. All fans shall be suitable for bi-directional rotation.

Conduit Box - shall be gasketed between the conduit box halves. A grounding provision shall be provided in the conduit box. The conduit box shall be oversize as compared to NEMA requirements and diagonally split and rotatable in 90 degree increments. The conduit box shall be field convertible to cast iron.

External screws and bolts - shall be grade five, hex heads and be plated to resist corrosion.

Motor Shaft - shall be provided with an external recessed slinger at the drive end of the motor to provide additional (minimum IP-54) protection from moisture and foreign material.

Rotor and stator air gap surfaces - shall be coated so as to prevent corrosion.

External Paint - shall be corrosion resistant - mill and chemical duty paint.

Nameplate - shall be of stainless steel and stampted per NEMA Standard MG1 Part 10 and Part 31. Nameplate information shall include as a minimum, the nominal efficiency value per NEMA Standard MG1 Part 12, the bearing identification numbers, power factor, Torque values with speed range and amps for that torque value. Nameplate also shall include Full Load Slip RPM, Magnetizing amps and (if included) encoder PPR and Voltage rating.

Motor Vibration - shall not exceed .08 inches/second velocity.

Noise Levels

Sound pressure levels shall be average expected values in accordance with values listed in Table 1. Sound pressure dBA shall be measured in a free field with average reading at three feet.

Tests

Tests shall be performed on each design to assure compliance with the critical design criteria of this specification for inverter duty motors.

Encoder tests, if included, all encoders shall be tested after assembly to the motor. Testing shall include verification of complete quadrature output and index pulse at a full range of speed.

Warranty

Motor components shall have a full three year performance warranty on inverter or sine wave power.