- Industry: Electrical equipment
- Number of terms: 4774
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Rating life, L10 (Bl0), is the life in hours or revolutions in which 90% of the bearings selected will obtain or exceed. Median life (average life), L50(B50)
Industry:Electrical equipment
A figure of merit which indicates how much rectified current departs from pure (non-pulsating) DC. A large departure from unity form factor (pure DC, expressed as 1.0) increases the heating effect of the motor and reduces brush life. Mathematically, form factor is the ratio of the root-mean square (rms) value of the current to the average (av) current or Irms/lav.
Industry:Electrical equipment
An external device or accessory that brings a running motor to a standstill and/or holds a load. Can be added to a motor or incorporated.
Industry:Electrical equipment
A type of coil in which each winding is individually formed and placed into the stator slot. A cross sectional view of the winding would be rectangular. Usually form winding is used on high voltage, 2300 volts and above, and large motors (449T and above). Form winding allows for better insulation on high voltage than does random (mush) winding.
Industry:Electrical equipment
The torque required to bring a motor down to a standstill. The term is also used to describe the torque developed by a motor during dynamic braking conditions.
Industry:Electrical equipment
A motor usually built in a frame smaller than that having a continuous rating of one horsepower, open construction, at 1700 -1800 rpm. Within NEMA frame sizes FHP encompasses the 42, 48 and 56 frames. (In some cases the motor rating does exceed 1 HP, but the frame size categorizes the motor as a fractional.) The height in inches from the center of the shaft to the bottom of the base can be calculated by dividing the frame size by 16.
Industry:Electrical equipment
The supporting structure for the stator parts of an AC motor; in a DC motor the frame usually forms a part of the magnetic coil. The frame also determines mounting dimensions (see frame size).
Industry:Electrical equipment
The maximum torque a motor will develop at rated voltage without a relatively abrupt drop or loss in speed.
Industry:Electrical equipment
Refers to a set of physical dimensions of motors as established by NEMA. These dimensions include critical mounting dimensions. 48 and 56 frame motors are considered fractional horsepower sizes even though they can exceed 1 horsepower, 143T to 449T are considered integral horsepower AC motors and 5000 series and above are called large motors. (For definition of letters following frame number, see Suffixes.
Industry:Electrical equipment
