Category: Company Updates

How to Choose an Automotive Relay

When searching for an automotive relay, it is important to follow the steps below to ensure you make the correct choice.

  • Determine the Voltage: Begin by identifying the voltage requirement for your automotive relay. Common voltages for automotive relays are 12V, 24V, or higher. Check the requirements of the electrical system to determine the correct voltage. 
  • Determine the Relay Layout: Automotive relays come in various layouts, with the two most common being Single Pole Single Throw (SPST) and Single Pole Double Throw (SPDT). An SPST relay has four pins, while an SPDT has five pins. 
  • Determine the Footprint: Automotive relays have different footprints or socket types for installation. The commonly used footprints include ISO Ultra Micro, ISO Micro 280, ISO Micro, ISO Mini, or ISO Maxi. Additionally, some automotive applications use PCB layouts. Refer to the layout diagrams below.

  • Determine the Continuous Rating: Consider the continuous rating of the relay, which refers to the maximum current that can flow through the contacts without causing damage. Automotive relays typically have continuous ratings ranging from 20A to 75A.
  • Specify Mounting Options: Determine whether your relay requires a bracket for mounting or if it can be installed without one. Some relays come with integrated mounting brackets, while others may require separate brackets for secure installation. Ensure compatibility with your vehicle’s mounting requirements.
  • Determine the Suppression: Automotive relays often require suppression to protect against voltage spikes and other electrical disturbances. Suppression options include resistors, diodes, or no suppression.

By following this process, you can narrow down the search for a suitable automotive relay. It is crucial to match the coil voltage, meet or exceed the current rating, and select the suppression type. By prioritizing these factors, one can enhance the overall efficiency and reliability of a system, ultimately leading to improved satisfaction and success within the industry.