Omron LY4 24VDC General Purpose Relay Technical Guide

The Omron LY4 24VDC general purpose relay is a four-pole electromechanical relay designed for industrial control systems, relay logic panels, machine automation, and electrical interface circuits. As part of the Omron LY bi-power relay family, this model is valued for its practical plug-in structure, transparent case, and dependable switching performance in control cabinet environments.

This relay uses a 24 VDC coil, one of the most common control voltages in industrial automation. It features a 4PDT contact arrangement, also known as four-pole double-throw. That means a single coil signal can switch four independent changeover circuits at the same time. This makes the relay useful for control systems that require coordinated switching, status feedback, interlock logic, alarm routing, or multiple auxiliary outputs from one control command.

Technical Characteristics

The Omron LY4 24VDC relay is specified as a plug-in relay with 14 pins, four poles, a 10 A rated carry current, silver alloy contacts, and a transparent case. Omron also lists the coil current as 69 mA and the coil resistance as 350 ohms for the DC24 version. The relay is designed for socket mounting, which helps simplify replacement, inspection, and maintenance without rewiring the whole circuit.

Its contact ratings include 10 A for resistive loads and lower ratings for inductive loads, depending on voltage and load behavior. This distinction matters because inductive devices such as solenoids, contactor coils, motors, and transformers can generate electrical stress when switched off. For those circuits, protective components may be required to support contact life and stable operation.

Common Applications

The Omron LY4 24VDC general purpose relay is commonly used in industrial automation panels, machine control systems, PLC output expansion, alarm circuits, safety-related auxiliary logic, test equipment, and building control systems. Its 24 VDC coil makes it especially suitable for use with modern control power supplies and programmable logic controllers.

Because the relay provides electrical separation between the coil and contact circuits, it can be used as an interface between low-voltage control devices and separate load circuits. The plug-in format also helps maintenance teams replace the relay quickly when troubleshooting, provided the correct socket and wiring standard are used.

Selection and Installation Notes

Before using this relay, engineers should verify the coil voltage, contact configuration, socket type, load current, switching voltage, ambient temperature, and duty cycle. The LY4 24VDC model is often associated with the PTFZ-14-E socket, but socket compatibility should always be confirmed against the final panel design.

For more technical context, visit Omron relay information.

FAQ

What is the Omron LY4 24VDC relay?

It is a general purpose electromechanical relay with a 24 VDC coil, plug-in terminals, and a 4PDT contact configuration.

What does 4PDT mean?

4PDT means four-pole double-throw. The relay can switch four separate changeover circuits simultaneously when the coil is energized.

Is the Omron LY4 24VDC suitable for PLC systems?

Yes. Its 24 VDC coil voltage matches many PLC control systems, but output current capacity and interface protection must be checked.

What socket can be used with this relay?

Omron lists compatibility with the PTFZ-14-E socket for DIN rail or surface mounting with screw terminals.

Can it switch inductive loads?

Yes, within the correct inductive load ratings. Inductive circuits should be reviewed carefully because they can reduce contact life if no suppression is used.