Omron LY2-0 24VAC General Purpose Relay

The Omron LY2-0 24VAC general purpose relay is a two-pole electromechanical relay intended for control circuits that operate from a 24 VAC supply. This voltage is common in building automation, HVAC equipment, panel controls, low-voltage AC control transformers, and machine interface circuits where safer control voltage is preferred over mains-level switching.

Technical Overview

The LY2-0 24VAC relay belongs to the Omron LY family and uses a DPDT, or 2 Form C, contact arrangement. Available product data for the LY2 AC24 version identifies it as a general purpose relay with a 24 VAC coil, 10 A contact rating, silver alloy contact material, plug-in or socketable mounting, and 25 ms operate and release times. Commonly listed electrical data includes 46 mA coil current, 180 ohms coil resistance, 19.2 VAC must-operate voltage, and 7.2 VAC must-release voltage.

Why 24 VAC Is Common in Control Systems

Many control systems use 24 VAC because it can be generated by a control transformer and routed through thermostats, switches, safety devices, and controller outputs. This relay allows a 24 VAC signal to operate contacts that can switch separate loads within the relay’s ratings. It is especially relevant in HVAC panels, fan control circuits, pump control, and auxiliary machine logic.

Omron LY2-0 24VAC DPDT Contact Function

With DPDT contacts, the relay can change the state of two circuits at the same time. For example, one pole may switch a load while the second pole sends feedback to a controller or indicator. This makes the relay useful where compact panel space and simple control architecture are important.

Application Considerations

Relay selection should never be based on coil voltage alone. The installer or engineer should confirm contact voltage, current, load type, operating temperature, switching frequency, socket type, and approval requirements. For inductive loads, proper suppression may reduce contact wear and improve long-term reliability.

Practical Installation Notes

The relay should be installed in a compatible socket or mounting arrangement and wired according to the circuit diagram. Before energizing the panel, verify coil terminals, contact terminals, protective devices, and conductor sizing. For additional Omron resources, visit Omron information.

FAQ

What is the Omron LY2-0 24VAC relay used for?

It is used to control electrical circuits from a 24 VAC coil signal. Common applications include HVAC systems, automation panels, auxiliary control circuits, and low-voltage AC control systems.

Is 24 VAC the same as 24 VDC for this relay?

No. AC and DC coil versions are not interchangeable. A 24 VAC relay must be used with a compatible AC control supply, while a 24 VDC version is intended for direct-current control.

What does must-operate voltage mean?

Must-operate voltage is the minimum voltage level at which the relay is expected to operate reliably under specified conditions. For the 24 VAC version, commonly listed data shows 19.2 VAC.

Omron LY2-0 24VAC What does must-release voltage mean?

Must-release voltage is the voltage level below which the relay should release and return to its normal contact state. This value helps designers understand drop-out behavior.

Can this relay be used in HVAC equipment?

Yes, 24 VAC relays are commonly used in HVAC control circuits. The final design must still match the relay’s load rating, wiring requirements, and environmental conditions.

Why choose a DPDT relay instead of SPDT?

A DPDT relay provides two changeover contacts instead of one. This is useful when two circuits must be controlled together from one coil signal.