Compressor Starting Relays and Capacitors) Hard Start Kits

 

Purpose and Usage

• Application: Converts moderate or low starting torque motors (e.g., PSC) to capacitor start-capacitor run motors.
• Reasons to Add:
  • Low voltage issues in systems (e.g., window air conditioners).
  • Older air conditioning systems with reciprocating compressors.
  • Compressors that may seize up due to dry cylinder walls (common in systems used infrequently).

Components and Wiring

• Components:
  • PTC relay.
  • Start capacitor.
• Wiring:
  • Wired from line voltage and placed across run capacitor terminals.
  • PTC relay heats up, breaking power to start capacitor, then current flows through run capacitor.

Benefits and Applications

• Low Voltage: Helps with starting under low voltage conditions.
• Tight Compressors: Assists in starting compressors that may be tight or seized.
• Life Expectancy: Can potentially extend compressor life.

Example Setup

• Existing Run Capacitor: Hard start kit wired across terminals.
• PSC Motor Operation:
  • Full current through PTC relay and capacitor in series with start winding.
  • PTC relay heats up, increasing resistance, breaking start capacitor circuit.
  • Motor runs like a PSC motor with run capacitor.

Hard Start Kit Variants

• Solid State Current Relay Kit:
  • Similar to hard start kit.
  • Includes start capacitor and current relay.
  • Used on systems without a run capacitor, wired directly from run to start windings.
• Three-in-One Kits:
  • Include PTC relay, start capacitor, and overload protector.
  • Replaces starting relay and adds start capacitor.
  • Easy wiring with color-coded terminal connections.

Wiring Instructions

• Connections:
  • Line voltage to hard start kit.
  • Blue wire to run winding.
  • Black wire to neutral or line two.
  • Red wire to start winding.
  • PTC relay and start capacitor in series with start winding.