Omron MY4 220/240VAC (S)

Omron MY4 220/240VAC (S) General Purpose Relay: Technical Guide for Control Panels

The Omron MY4 220/240VAC (S) general purpose relay is a compact electromechanical relay designed for industrial control, automation panels, machine interfaces, and auxiliary switching circuits. It belongs to Omron’s MY series, a widely used relay family known for plug-in installation, dependable contact behavior, and compatibility with socket-based panel wiring. This model uses a 220/240 VAC coil and provides a 4PDT contact arrangement, making it suitable when one control signal must switch multiple independent circuits.

According to Omron’s published product data, the MY4 AC220/240 version is a miniature power relay with plug-in terminals, a 4PDT contact form, single contacts, Au-clad silver alloy contact material, and rated loads of 3 A at 220 VAC for resistive loads and 0.8 A at 220 VAC for inductive loads. Its DC load ratings include 3 A at 24 VDC for resistive loads and 1.5 A at 24 VDC for inductive loads. The coil current is listed as 4.8 mA at 220 VAC 50 Hz, 4.2 mA at 220 VAC 60 Hz, 5.3 mA at 240 VAC 50 Hz, and 4.6 mA at 240 VAC 60 Hz. The coil resistance is 18,790 ohms, and the operate voltage is 80% maximum. :contentReference[oaicite:0]{index=0}

Where This Relay Fits Best

The Omron MY4 220/240VAC (S) relay is especially useful in control systems where the available control voltage is mains-level AC. Typical use cases include industrial control cabinets, HVAC control panels, pump control systems, lighting control circuits, machine interlocks, alarm circuits, and auxiliary command logic. Because it is a plug-in relay, maintenance teams can replace the relay quickly without rewiring the entire circuit, provided the correct socket and wiring layout are used.

The 4PDT configuration gives the relay four changeover contacts. In practical terms, this allows one coil to operate four separate switching paths at the same time. For example, one contact may be used for a signal lamp, another for an interlock, another for a PLC input, and another for a control circuit. This makes the relay useful when designers want clean circuit separation while still using a single control command.

Key Technical Characteristics

  • Brand and model: Omron MY4 220/240VAC (S)
  • Product type: General purpose electromechanical relay
  • Coil voltage: 220/240 VAC
  • Contact form: 4PDT
  • Terminal structure: Plug-in terminal
  • Contact material: Gold-clad silver alloy
  • Rated resistive load: 3 A at 220 VAC
  • Rated inductive load: 0.8 A at 220 VAC
  • Typical application: Industrial control panel switching

Design Notes for Engineers and Maintenance Teams

When selecting the Omron MY4 220/240VAC (S) general purpose relay, the most important starting point is the coil voltage. This version is intended for 220/240 VAC control circuits, so it should not be substituted with 24 VAC or 24 VDC versions unless the control circuit is redesigned. Contact ratings should also be reviewed carefully. Resistive loads are generally easier for relay contacts to switch, while inductive loads such as coils, solenoids, and contactors can create voltage spikes during turn-off. In those applications, proper suppression and load derating help improve service life.

The plug-in format is a strong advantage in production environments. It supports faster replacement, cleaner cabinet layouts, and easier troubleshooting. For broader Omron relay options and related components, see Omron industrial automation components.

Omron MY4 220/240VAC (S) FAQ

What is the Omron MY4 220/240VAC (S) used for?

It is used for switching multiple control circuits from one 220/240 VAC coil signal. Common applications include automation panels, machine control systems, HVAC control circuits, auxiliary relays, alarm circuits, and electrical interlocking systems.

Is Omron MY4 220/240VAC (S) a 4PDT relay?

Yes. This relay has a 4PDT contact arrangement, meaning it provides four changeover contact sets. This allows one relay coil to switch four independent circuits at the same time.

Can this relay switch inductive loads?

Yes, but inductive loads must be handled carefully. Omron lists an inductive load rating of 0.8 A at 220 VAC. Loads such as solenoids, contactor coils, and electromagnetic valves may require surge suppression to reduce arcing and extend contact life.

What is the difference between 220/240VAC and 24VDC MY4 versions?

The main difference is the coil voltage. The 220/240VAC version is energized by mains-level AC control voltage, while the 24VDC version is designed for low-voltage DC control systems, often used with PLC outputs and industrial power supplies.

Omron MY4 220/240VAC (S) Why is the plug-in terminal structure important?

A plug-in relay can be removed from its socket without disconnecting every wire. This reduces downtime, simplifies replacement, and supports organized control cabinet maintenance.

Is this relay suitable for PLC interface circuits?

It can be used in PLC-related control systems when the coil voltage, contact load, and wiring design match the application. However, many PLC systems use 24 VDC outputs, so engineers must confirm that a 220/240 VAC coil is appropriate before installation.

Does the Omron MY4 220/240VAC (S) have gold-clad contacts?

Yes. Omron specifies Au-clad silver alloy contacts for this version, which helps support reliable signal transfer in suitable control applications.

What should be checked before replacing an existing relay with this model?

Check the coil voltage, contact form, socket compatibility, terminal layout, load type, load current, operating environment, and any required approvals. Matching the physical socket alone is not enough; the electrical specifications must also fit the circuit.