Run Start Capacitor, Round, 70/7.5 MFD, 440/370

Mars 12166 – 70/7.5 MFD 440V Dual Run Capacitor, Round Case

The Mars 12166 is a dual-section motor run capacitor rated at 70/7.5 microfarads (MFD) with a voltage rating of 440 VAC. It is engineered for use in permanent split capacitor (PSC) single-phase motor circuits, where it supports both compressor and condenser fan motors in HVAC systems. This unit is suitable for use in air conditioning and heat pump applications requiring dual capacitance values in a compact, round aluminum canister.

Manufactured to meet EIA-456-A performance specifications, the Mars 12166 offers reliable service life and consistent performance under high-cycle operating conditions. The capacitor is oil-filled, non-PCB, and includes a pressure-sensitive interrupter for integrated safety shutdown in case of internal fault.

Technical Specifications

• Capacitance: 70/7.5 MFD ±6%
• Voltage Rating: 440 VAC, 50/60 Hz
• Type: Dual Motor Run Capacitor
• Shape: Round aluminum shell
• Terminals: ¼" male quick-connect, clearly labeled C, FAN, and HERM
• Dielectric: Oil-filled, non-PCB
• Temperature Range: -40°C to +70°C

Physical Dimensions

• Diameter: Approx. 2.5 inches
• Height: Approx. 5.0 inches (without terminals)

Installation Requirements

The Mars 12166 should be installed by trained HVAC professionals. Proper installation includes verifying the original capacitor ratings, safely discharging the failed unit, and confirming wire placement in accordance with system wiring diagrams. Use appropriate mounting hardware and ensure terminal leads are secured to avoid vibration damage or arcing.

HVAC System Application

This capacitor is commonly used in dual-motor systems within residential and light commercial condensing units. It supports both compressor and condenser fan motors and eliminates the need for two separate capacitors, reducing component count and simplifying panel layouts.

Contractor-Oriented Advantages

• ✅ Dual Capacitance Support: 70 MFD for compressor / 7.5 MFD for condenser fan
• ✅ 440V Rating: Rated for high-stress electrical environments with fluctuating voltage
• ✅ UL Recognized: Complies with industry safety and reliability standards
• ✅ Built-In Interrupter: Provides internal circuit disconnect under overpressure conditions
• ✅ Round Form Factor: Compatible with OEM capacitor brackets and standard installation locations