How to Choose Between a Relay, Solenoid, and Contactor: A Simple Guide to MurCal’s Products
Published on
November 22nd, 2024
When working with electrical systems, choosing the right component is key. Whether you're building a marine engine, an industrial machine, or an automotive system, deciding between a relay, solenoid, or contactor will affect your system's performance. At MurCal, we carry a range of these components, each designed for specific uses. Here’s a simple guide to help you choose the right one.
What Are Relays, Solenoids, and Contactors?
Before diving into which one to use, let’s quickly go over what each part does:
Relay: A relay is an electrically operated switch that controls smaller circuits. It uses a small current to switch a larger one on or off.
Solenoid: A solenoid is an electromagnet that creates mechanical motion when electricity flows through it. It’s used to move objects like valves or locks.
Contactor: A contactor is similar to a relay but built for high-power applications. It’s used to control large electrical loads, such as motors and heavy machinery.
When to Use a Relay, Solenoid, or Contactor
Each of these components works best in different situations. Here’s when you should choose each one:
1. Relays: For Low-Power Circuits
Relays are perfect when you need to control low-power electrical systems. They’re commonly used in:
Automotive: Relays control things like headlights, fuel pumps, and wipers. MurCal carries relays for automotive applications, offering great reliability and performance.
Marine: In boats, relays are used to control lights, alarms, and other small accessories.
Industrial: Relays are great for controlling small motors and sensors in industrial systems.
MurCal offers relays that are easy to install and feature Deutsch™ connectors for better reliability, especially in tough environments.
2. Solenoids: For Mechanical Movement
Solenoids are best for mechanical tasks like moving a valve or locking a door. They're used in:
Valve Control: Solenoids are often found in HVAC systems, machines, or boats to control the flow of fluids or gasses.
Locking Systems: Many electronic locks use solenoids to open or close doors.
Automotive: Solenoids also help manage fuel injectors and other engine components.
At MurCal, we offer durable solenoids that perform reliably, even in harsh conditions like saltwater environments.
3. Contactors: For Heavy-Duty Electrical Switching
Contactors are designed for high-power applications, such as:
Motor Control: If you need to control large machines or motors, a contactor is the right choice. MurCal’s contactors are built to handle industrial equipment and marine systems.
Lighting Systems: Contactors are also used in large lighting systems for commercial buildings or outdoor setups.
Power Systems: Contactors are used to manage large electrical systems, like generators.
MurCal offers heavy-duty contactors that are weather-sealed to ensure they can handle exposure to moisture, salt, and harsh environments.
Key Differences to Remember
Power Handling: Relays are for small to medium electrical loads, while contactors are designed for large, high-power circuits. Solenoids are for mechanical tasks.
Environment: MurCal's relays and contactors are sealed for harsh conditions, making them great for marine and industrial environments.
Function: Relays are for switching small electrical loads, solenoids are for moving objects, and contactors are for controlling large electrical systems like motors.
The Bottom Line
Choosing between a relay, solenoid, and contactor depends on your specific application.
By understanding the differences and when to use each, you’ll be able to make an informed choice that keeps your systems running smoothly and reliably.
------------------
For Technical Support, Please Call Us At 661-272-4700, Contact Us Or Email Us At Sales@Murcal.Com
-----------------
Don't Miss a Thing!!! 🤩
Subscribe to our newsletter, follow us on Instagram, LinkedIn, Twitter/X, Facebook, TikTok & Threads to keep up to date with our latest News, Sales, Trends and more! Don't forget to check out our Blog archives for more expert informational content.
A Decades-Long Tradition Meets the Future: MurCal at the 2026 World Ag Expo
For the MurCal team, the annual trip to Tulare, California, for the World Ag Expo is more than just a business trip—it’s a piece of our history. Our founders, Art and Essie Murphy, were there at the very beginning, attending the very first show back in 1968. Nearly 60 years later, we are still proud to be a part of the world’s largest outdoor agricultural show.
EGIS Thermal Circuit Breakers: Built for Reliable Marine Power
At MurCal, we’re proud to highlight EGIS Mobile Electric as our Brand of the Month. Their thermal circuit breakers are built for reliability and tough marine conditions. Made with precision American engineering and backed by a 4-year warranty, these breakers protect your boat’s electrical system with proven quality.
Spotlight on EGIS Mobile Electric: Remote Sealed Relay Switches!
At MurCal, we’re excited to spotlight EGIS Mobile Electric as our Brand of the Month for January 2026, with a special focus this week on their standout Remote Sealed Relay Switches (Single 160A / Dual 80A Outputs). These innovative switches are popular for their rugged design that tackles the toughest power management challenges in mobile environments, making them a go-to for professionals who can’t afford downtime.
Tech Jargons Explained Part 2: Industrial Controls Guide
In Part 1 of “Tech Jargons Explained: A Simplified Guide to Industrial Controls and Instrumentation from MurCal,” we covered the core terms behind Swichgages®, gauges, and basic controllers. Now in Part 2, we’re diving deeper into advanced concepts from MurCal’s full product range—J1939 CAN modules, engine controllers, battery chargers, level maintainers, solenoids, and remote monitoring systems—so you can tackle complex systems with total confidence.
EGIS Mobile Electric: Built Tough, Engineered Smart for Real-World Reliability
At MurCal, we hand-pick brands that deliver real reliability for our customers’ tough jobs. That’s why we’re excited to spotlight EGIS Mobile Electric as our January 2026 Brand of the Month. Based in Bellingham, Washington, EGIS makes rugged electrical parts that keep power flowing in the harshest conditions—like bumpy trucks, wet boats, and dusty job sites.