Glossary

The list below contains some common terms and abbreviations used in the electric motor industry

Belly Band- Also called a spider mount. A mount that goes around a round body motor that uses friction to hold the motor in place and has flanges to mount to the equipment.

Enclosure- How the motor is protected from exterior forces like rain and dust. The most common enclosures are OPD, TEFC, TENV, TEAO, and OAO. For explanations on these enclosures, go to their place in the glossary.

Frame- Either a 2 or 3 digit number giving information about the mounting and shaft dimensions. Examples are 48 or 324

Frame Suffix- Letters AFTER the frame. The give more information about the shaft and mounting dimensions. If the letters are before the frame, they have no standardized meaning, and can be ignored for the most part. Examples are 48YZ or 324T.

HP- Horsepower. A unit of measurement of power. Usually expressed as either a fraction or an integer.

Mount- How the motor is mounted. Common mounts include rigid base, resilient base, belly-band, stud mount. See each term for a more detailed explanation.

OAO- Open Air Over. An enclosure for a motor that is not totally enclosed, and must be mounted in the air-stream to maintain proper operating temperature.

ODP- Open Drip-proof. An enclosure for a motor that is not totally enclosed, and does not need to be mounted in an air-stream to maintain proper operating temperature.

Resilient Base- Also known as a cradle or cushion mount. A base the motor sits in that cradles the entire length of the motor body. It is used to cut down on vibration noise, and is commonly used in fractional horsepower motors.

Rigid Base- Also known as foot mount, or welded base. A foot, with mounting holes, welded to the barrel of the motor.

RPM- Revolutions Per Minute. Also see Pole. This measures the speed that the shaft spins. Most motors are either 3600, 1800, 1200, or 900 (rounded). A more accurate way of measuring the RPM of a motor is by how many poles the motor has. Your motor may not be labeled with an even number like the examples. Just round up (always up) to the next closest RPM value.

TEAO- Totally Enclosed, Air Over. An Enclosure for a motor that is totally enclosed from exterior forces like water and/or dust. Air over motors must be mounted in the air-stream to maintain proper operating temperatures.

TEFC- Totally Enclosed, Fan Cooled. An Enclosure for a motor that is totally enclosed from exterior forces like water and/or dust, but has a built in fan on the opposite shaft end to cool the motor down while in operation.

TENV- Totally Enclosed, Non-Ventilated. An Enclosure for a motor that is totally enclosed from exterior forces like water and/or dust, and does not need a fan to maintain proper operating temperature.