Single Run Capacitor, Round, 35/370 uF

Mars 12218 – 35 MFD 370V Round Run Capacitor for HVAC Systems

The Mars 12218 is a 35 microfarad (MFD), 370 VAC-rated single-value round run capacitor designed for use in residential and light commercial HVAC systems. This component provides continuous voltage regulation to fan motors and compressors in air conditioning and refrigeration units, ensuring consistent performance and extended equipment life.

Part of the Mars Blue Box capacitor line, the 12218 is constructed with non-PCB dielectric material and features a built-in pressure-sensitive interrupter for added system protection in overpressure conditions. Its compact aluminum case design allows for straightforward integration into existing control compartments.

Application Overview

Engineered to meet UL and EIA standards, this capacitor supports permanent split capacitor (PSC) motor designs in condenser fan and compressor circuits. Its 35 MFD capacitance and ±6% tolerance rating ensure compatibility with a wide range of OEM and aftermarket equipment specifications.

Key Technical Features

• ✅ Capacitance Rating: 35 microfarads (MFD) ±6%
• ✅ Voltage Rating: 370 VAC, 50/60 Hz
• ✅ Case Material: Rolled aluminum with plastic top
• ✅ Terminals: Four-terminal design for simplified field wiring
• ✅ Dielectric: Non-PCB, oil-filled with built-in physical interrupter
• ✅ Operating Temp Range: -40°C to +70°C

Product Dimensions

• Case Diameter: 1-3/4 inches
• Case Height: 3-3/4 inches
• Overall Height: 4-1/4 inches

Installation Requirements

This capacitor should be installed by qualified HVAC personnel. Correct polarity and secure terminal connections are essential to prevent electrical faults. Verify all electrical power is disconnected before servicing equipment. Mount only in approved enclosures or brackets per system manufacturer's instructions to maintain compliance with UL standards and local codes.

Contractor Notes

The Mars 12218 is suitable for use in OEM equipment replacements and as a general-purpose run capacitor in PSC-driven systems. Its physical interrupter and non-PCB dielectric support both safety and environmental standards required in modern field service. The compact form factor and terminal configuration make it ideal for fast replacements in constrained service panels.

Summary of Attributes

• ✅ Reliable Motor Start/Run Support – Maintains system efficiency by stabilizing current flow to motor windings.
• ✅ Safety Interrupter – Provides fail-safe function by disconnecting capacitor internally upon pressure buildup.
• ✅ UL Recognized (EIA-456 Compliant) – Verified for safety and longevity under HVAC operational loads.
• ✅ Service-Grade Construction – Meets field performance demands with consistent capacitor stability.