Page 317 - Electronic Mechanic - TP - Volume - 2

ELECTRONICS MECHANIC - CITS

EXERCISE 214: Understand all the information on a motor
template

Objectives

At the end of this exercise you shall be able to:
• to study information on a motor template.

Note: A nameplate contains a large amount of useful information relating to the motor including the type
RPM frame size and power of the motor. By the template we can easily recognize which type motor we
are using.

Procedure

1 Number of Phases: This shows the type of power supply for which the motor is designed. There are single
phase and three phase motors.

2 Rated Operating Voltage: This shows at which voltage is the motor is designed to operate most efficiently.
Motors are designed to operate at +/-10% tolerance of this value.
Other parameters show on the nameplate including power factor efficiency, torque and current are at rated
voltage and frequency. Using the motor at rated voltage and frequency. Using the motor outside this tolerance
will most probably lead to different performance.
3 Service Duty: In this case S1 shows that this is a continuous duty motor that works at a cinstant load for
enough time to reach temperature equilibrium.
The parameter Duty/Time rating represents the period of time during which the motor can run a its nameplate
rating/rated load safely and indicates whether the motor is rated for continuous duty.
This is shown as “CONT” for continuous duty 24/7 but they can also have a short-time rating form 5 to 50
minutes. Most motors are rated for continuous duty.

The rating of the motor is the ambient temperature vs. the time it can operate at that temperature. The ELC
break this down into ten ratings.
4 Efficiency Code: This shows the percentage of the input power that is actually converted to work output form
the motor shaft. The motor will have a nominal efficiency shown on the plate. This is the average efficiency.
The closer this value is to 100% the low the electricity consumption cost is going to be.
The four levels if motor efficiency are
• IE - Standard Efficiency
1
• IE - High Efficiency
2
• IE - Premium Efficiency
3
• IE - Super Premium Efficiency
4
5 Frame Size: This shown the frame size. The frame size determines the mounting dimensions such as the foot
openings pattern and the shaft height.
The dimension of the electric motor based on the NEMA system for fractional hp motors have two digits and
represent the shaft height from the base’s bottom in sixteenths of one inch.
For large motors the frame size has three digits. The first two digits stand for the shaft height in on quarter of an
inch. The third digit is the bolt mounting holes dimension. The longer the motor body. The longer the distance
between mounting bolt holes in the base. Finally, the letter is the type of frame.
The same concept applies for IEC type motors but the height is measured in millimetres instead of inches.

6 Degree of Protection: The IEC uses a two-digit ingress protection rating to measure how well the motor is
protection form the environment. NEMA uses an enclosure description that is of a similar standard.

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