Overview
The Dayton 340-408MFD motor start capacitor is engineered for intermittent duty in single-phase AC motor starting circuits. With a 340–408 microfarad rating and 110/125VAC voltage specification, this unit provides dependable starting torque for fractional horsepower motors in HVAC systems, refrigeration compressors, water pumps, and similar industrial and commercial equipment. Factory-tested and UL recognized for US and Canada operation.
Key Features
- 340–408 microfarad (µF) capacitance rating with ±6% tolerance
- Hermetically sealed phenolic resin case protects against oil, dirt, grease, and moisture
- 50/60 Hz dual frequency operation for worldwide compatibility
- Rated for 20 motor starts per hour with 3-second start capability
- Non-polarized aluminum electrolytic construction for intermittent motor duty
- Standard dual blade connectors enable quick terminal connection
- UL Recognized (E224674) certification for safety compliance
- Made in the U.S.A. to EIA standards for quality assurance
Technical Specifications
- Capacitance Rating: 340–408 microfarads (µF)
- Voltage Rating: 110–125VAC
- Frequency: 50/60 Hz
- Capacitor Type: Motor start (intermittent duty)
- Case Material: Phenolic resin (hermetically sealed)
- Case Height: 3.38 inches
- Width/Diameter: 1.44 inches
- Terminal Type: 2 standard dual blade connectors
- Operating Temperature Range: −40°C to +65°C (−40°F to 149°F)
- Starts Per Hour Rating: 20 starts/hour
- Certifications: UL Recognized (E224674) for US and Canada
Typical Applications
Motor start capacitors in the 340–408 microfarad range are ideal for:
- Single-phase AC motor starting torque enhancement
- Soft-start applications in compressors and pump motors
- HVAC system blower and condenser motor circuits
- Fractional horsepower electric motors in residential and commercial systems
- OEM replacement in existing motor equipment with equivalent ratings
Compatibility & Replacements
Compatible With
- Single-phase AC motor circuits rated 110–125VAC
- Fractional horsepower compressor and pump motors
- HVAC blower and condenser motor starting circuits
- Standard dual-blade capacitor terminal connectors
- Motors requiring 340–408 microfarad start capacitors
Replaces / Drop-In Replacement For
- Aerovox Dayton 4X067
- MARS 11022
- JARD 11922
- PMJ340 and PMJ340A (Packard)
- Vanguard BC-340
- Global 1022
- Mallory PSU34015
- Other 340–408 µF / 110–125VAC motor start capacitors
Works With
- Any AC motor system designed for 340–408 microfarad capacitors at 110–125VAC
- OEM replacement applications across HVAC, refrigeration, and general motor equipment
- Standard motor mounting brackets and phenolic case-compatible terminals
- Verify compatibility with your system integrator before ordering for non-standard applications



