It is important to check the design letter when replacing a motor in an existing application. This is known as slip. The standard frequency is 60 Hz in North America and usually 50 Hz elsewhere. Bearings Bearings are the component in an AC motor that requires the most maintenance. Some common markings are: Most motors have a duty factor of 1.
After motor cools,thermal protector automatically restores power.
However, given the proper information about the ASD and application, a motormanufacturer can design a motor, or properly apply an existing design, and stamp the approvedparameters on the nameplate.
Some motors might have a higher value and others might belower, but the average of all units tested is shown as the nominal nameplate value. Full length of shaft is round. Such information is usually given for both the drive-end bearing and the bearing opposite the drive end.
Can indicate a special base, face or flange. Synchronous speed is the speed at which the motor would run if it were fixed to the ac power line frequency; that is, if it turned at the same speed as the rotating magnetic field created by the combination of winding pattern and power line frequency.
The most important ones are: The nameplate lists the maximum ambient temperature at which the motor can operate and still be within the tolerance of the insulation class at the maximum temperature rise.
Sequential, identical cycles of starting,running at constant load and running with no load. The letter designation describes the torqueand current characteristics of the motor.
This in turn affects the overall life span of the motor. The number describes the mounting dimensions, including foot holemounting pattern, shaft diameter, shaft height, etc.
On larger 3-digit frame size motors, T through T, a slightly different system is used where the first two digits represent the shaft height in quarters of an inch. The FF flange has through bolt holes, and isavailable for frame sizes from 56 to Most motors are design B because of their comparatively high efficiency and torque characteristics.
However, unless a drip cover is used for shaft-up or shaft-downapplications, drip-proof motors must be mounted in the horizontal or sidewall position to meet theenclosure definition. Contains a temperature-sensing device that disconnects one leg of its powersource if temperature becomes excessive due to failure-to-start or overload.
Sequential, identical dutycycles run at constant load and given speed, and then run at other constant loads and speeds. The NEMA definition for short-time motors is as follows: This is useful for applications with brief heavy overloads. In recent years, this type of mounting has become widely used on auger drives in poultry feeders.
In dual-voltage motors, one voltage value is typically twice the other one. Mount motors securely to the mounting base of equipment or to a rigid, flatsurface, preferably metallic.
UL indicates that the manufacturing system and the motorcomponents meet the standards of, and are continually reviewed by, Underwriters Laboratories. Heavy-duty motors for general mechanical loads, which are typically hard to start.
In many cases, valves are rarely opened and closed. It provides much information about the bearings and lets you buy bearings from a local distributor. NEMA defines standard voltage rating for three-phase motors. Power factor for a motor changes with its load.Interpreting Motor Nameplate Data typical motor nameplate.
’ Identify the information listed on typical motor nameplates. Manufacturer Phase/Frequency NEMA Design Letter Induction motors are able to operate at +/- 5% of the rated frequency with no deviation from rated. Motor nameplate is normally located on all produced electric motors.
Understanding nameplate information can be hard sometimes, but is essential. In most countries it is a requirement for manufacturers to display all information on the motor’s nameplate, but often this is not the case. Description: fresh-air-purifiers.com PDH Course E fresh-air-purifiers.com Page 1 of 21 Understanding Motor Nameplate Information Like this book?
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What Do All Those Things on an AC Motor Nameplate Mean? Introduction: Ever order a motor on power, speed, and enclosure?
"Nameplate Marking for Medium Single-Phase and Polyphase Induction Motors," of the NEMA standard requires that "The following minimum amount of information shall What Do All Those Things on an AC Motor Nameplate.
The U.S. motor industry has worked on a standardized basis for more than three-quarters of a century. The standardization agency National Electrical Manufacture. Knowing how to read the information on a motor nameplate will allow you to identify performance characteristics and applications of an electric motor.
Nominal efficiency mist be included on polyphase induction motor name-plates when required by NEMA.
Service Factor (SF). Other Terms That Might Show On An Electric Motor Template: .Download