Start & Run Capacitors

Start Capacitors

• Used to increase starting torque 300 to 500%
  
  
• High micro farad ratings 75 to 600 MFD
  
  
• Intermittent duty in circuit during start up
  
  
• Voltage supplied to capacitor must never exceed 150% of capacitor rating
  
  
• Rated voltage may be greater than Name plate Voltage due to BEMF
  
  
• Strength of replacement capacitor must be within 20% of OEM
  
  
• Bleed resistor 15000 to 20000 ohms (prevents arcing and sparking across staring device switch
  
  
• Phenolic plastic housing
  
  
  
  
  

Run Capacitor

• Used to improve power factor and reduce current drive
  
  
• Relatively low micro farad rating 2 to 6 mfd
  
  
• Continuous duty
  
  
• Voltage applied to capacitor must never exceed 110% of capacitor rating
  
  
• Rated voltage of a capacitor must be greater than the applied
  
  
• Strength of replacement capacitor must be within 10 % of OEM of + 5 mfd
  
  
• Identified terminal must be connected to line(ground) side (dab of paint) (if capacitor shorts it goes to ground)
  
  
• Drawn metal case

Bleed Resistors

• Purpose of a bleed resistor is to discharge the capacitor during the off cycle
  
  
• Bleed resistor helps to save the contacts on a start device