What is DC Contactor?

A DC Contactor is an electrical switching device that has the ability to handle high current levels. The contactor functions by applying a voltage to the coil, this creates a magnetic field which moves the contacts to the closed position and completes the circuit. Once voltage is removed from the coil, the contacts will open back up and disconnect the circuit. The large contact surface and the high amount of contact pressure allows the contactor to handle the higher in-rush currents typically seen in the mobile equipment markets.

Core Features of DC Contactors

Full Silver Powerseal

  • Uniquely designed for high-amperage applications
  • Ability to withstand tough environmental conditions


  • Hermetically sealed to ensure switching functions under harsh conditions
  • Designed to provide low-current switching while in low-temperature situations

Reverse Polarity

  • Cost-effective solution 
  • Built with a compact and economical approach


  • Features a high current capacity
  • Proven rugged design

200A Latching Battery Separator 

  • Ability to monitor voltage levels of two batteries and connect both to the alternator for charging 
  • Built to endure harsh conditions 

Plastics Family

  • Enhanced sealed options
  • Built with a compact and economical approach

PowerSeal Family

  • Optimized for high-performance at a competitive price
  • Includes a sealed construction

Solid State Relay

  • Long lifespan compared to other contactor in its class
  • Tolerates harsh environmental factors, including vibration, moisture, debris and a large range of operating temperatures

Metal Family

  • Traditional DC contactor that is still used in a variety of application

Smart Contactor

  • Programmable rating
  • Ultra lightweight
  • Improved reliability 
  • Environmentally sealed

Most Common Application

DC Contactors are best suited for high current applications such as:

  • Heavy duty heating
  • Motor
  • Energy storage systems
  • Vehicle battery systems (Agriculture, construction, heavy trucking, lawn and garden and marine equipment)

SMP’s DC Contactors are designed and constructed to be robust and cost-effective. We offer a broad selection of the best performing standard DC contactor designs that can be customized to meet a customer’s exact specifications, including coil operation and mounting bracket configuration. They can be used as components in new systems or as OEM replacement parts in existing systems.

Frequently Asked Questions About Our DC Contactors

What are the key features of SMP Trombetta’s DC Contactors? Our long-lasting life DC Contactors are durable and designed to withstand harsh environmental conditions.

What is the life expectancy of a DC Contactor? Life cycle varies by family, but it is regularly varied by testing. 

Will DC Contactor work in a lithium-ion battery application? Yes, but a special input voltage circuit is required. Please refer to our smart contactor for more information. 

For pricing or other details about one of our products, contact us today, and view our Product Families above.