General Electric 26F1650 2,5µF/370VAC 35x55x85mm motor run capacitor with 4x 6,3x0,8mm faston terminals

A motor capacitor, such as a start capacitor or run capacitor is an electrical capacitor that alters the current to one or more windings of a single phase AC induction motor to create a rotating magnetic field. Commonly motor capacitors are categorized as a motor run capacitors and motor start capacitors. Motor run capacitors are intended for continuous operation and as the name suggest motor start capacitor helps motor to start up. Ie some motors do only have one motor run capacitor and some do have motor run capacitor and motor start capacitor (separately or as a combination capacitor). The units of capacitance are labeled in microfarads (µF or uF or "mfd" or "MFD", which still refers to "micro", not "milli" or "mega").

Typical motor capacitor fault symptoms:

• Capacitor is swollen/cracked/blown/leaked
• Motor is weak
• The motor makes an exceptionally high vibration / buzz (may also indicate a bearing failure, for example)
• Motor does not start spinning without help (although spins freely by itself when spun manually, ie nothing caches to anything internally)
• The charge capacitance µF value of the motor capacitor differs from the value stated value by more than the given tolerance when measured with a LCR meter or a multimeter capable measuring  capacitors
• Motor smells burned (could also be a motor failure)
• Motor blows a fuse (could also be a motor failure)

Capacitor technical details:

• Capacitance:
  • 2,5µF
• Intended use:
  • Electric motor run capacitor
• Max operating voltage:
  • 370VAC 60Hz
• Climatic conditions according to IEC 60068 standard:
  • Not stated
• Mounting:
  • Use your imagination
• Overall dimensions:
  • 35x55x85mm
• Connectors:
  • 4x 6,3x0,8mm faston terminals

Below is an indicative table of capacitor size classes for motors. Primarily check/follow the motor manufacturer's instructions/values. If you need to round the value to a suitable capacitor then we recommend rounding up to the next closest suitable, as long as you do not have to deviate more than 5% from that correct value. The aged capacitors we have encounter lose their charge capacity with age (µF value decreases) therefore we recommend rounding up.

Download general info about AC motor capacitors and how to size and calculate motor capacitor by Kemet