Omron MY4 6VDC (S) Miniature Power Relay Technical Guide
The Omron MY4 6VDC (S) miniature power relay is a compact plug-in electromechanical relay designed for control panels, automation circuits, machine interfaces, and low-voltage DC switching systems. Built within Omron’s MY relay family, it combines a practical 4PDT contact arrangement with a 6 VDC coil, making it suitable for applications where multiple isolated circuits must be switched from one DC control signal.
This relay is commonly used in industrial control cabinets, electronic control assemblies, test equipment, small machinery, signal distribution circuits, and replacement work in legacy systems. The MY4 format is especially valued because it allows four independent changeover contacts in a compact housing, reducing panel space while maintaining flexible circuit design.
Core Technical Features
The Omron MY4 6VDC (S) miniature power relay uses a 4PDT contact form, also known as four Form C contacts. Each pole includes a common terminal, normally open terminal, and normally closed terminal. This structure allows one relay coil to control four circuits at the same time, which is useful for control logic, indication circuits, auxiliary switching, and interlock functions.
Omron’s MY series is described as a miniature power relay range with plug-in terminals, socket compatibility, optional indicators, and arc barriers on four-pole versions. The MY4 family is commonly associated with a maximum switching current of 5 A for four-pole models, along with dielectric strength of 2,000 VAC between coil and contacts. These characteristics support dependable use in control environments where electrical separation and serviceability matter.
6 VDC Coil Operation
The 6 VDC coil makes this relay suitable for systems powered by low-voltage DC control boards, regulated DC supplies, or battery-assisted control circuits. A DC relay coil must be supplied with the correct polarity when indicators or suppression components are included. This is especially important when replacing an existing relay, because using an AC coil in a DC circuit, or using the wrong DC voltage, can cause chatter, overheating, or failure to operate.
In practical installations, the coil supply should be stable and within the relay’s rated operating range. Voltage drop across long wiring runs, weak power supplies, or overloaded control transformers can prevent reliable operation. For this reason, technicians should confirm the measured voltage at the relay socket, not only at the power source.
Applications and Engineering Use
The Omron MY4 6VDC (S) miniature power relay is useful where a low-voltage DC signal must switch several independent outputs. Typical examples include PLC interface circuits, alarm panels, small automation machines, signal conversion panels, battery-powered control systems, monitoring equipment, and test benches.
Because it is a plug-in relay, it can be installed with compatible PY or PYF series sockets. This makes troubleshooting and replacement faster than hardwired or soldered relay solutions. In maintenance environments, socket-mounted relays reduce wiring disturbance and help keep panel work organized.
Selection and Replacement Notes
Before selecting this relay, confirm the exact coil voltage, coil type, terminal layout, contact rating, socket type, and accessory requirements. The “S” designation is commonly associated with models supplied with specific MY series features, so the full part number should always be matched against the existing component or machine documentation.
For contact loads, engineers should check whether the circuit is resistive or inductive. Resistive loads are generally easier to switch, while inductive loads such as solenoids, relay coils, contactor coils, and small motors create electrical stress during opening. Proper surge suppression may improve contact life and reduce electrical noise.
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FAQ
What is the Omron MY4 6VDC (S) used for?
It is used for low-voltage DC control circuits where one relay must switch four independent circuits. It is common in automation panels, machine control systems, alarms, and signal interface circuits.
Is the Omron MY4 6VDC (S) an AC or DC relay?
It is a DC coil relay. The coil is rated for 6 VDC, so it should be powered by a suitable 6 VDC control supply.
Can it replace an Omron MY4 6VAC relay?
No. A 6 VDC relay and a 6 VAC relay are not direct substitutes. The coil voltage type must match the control circuit.
Omron MY4 6VDC (S) What does 4PDT mean?
4PDT means four-pole double-throw. It allows four separate circuits to change state at the same time when the relay coil is energized.
Why should socket compatibility be checked?
Socket compatibility affects wiring layout, current capacity, mounting style, and replacement safety. A relay may physically fit one socket style but still require rating verification.
Is this relay suitable for PLC interface circuits?
Yes, it can be used in PLC interface circuits when coil voltage, output capacity, load type, and suppression requirements are correctly matched.
What should be checked if the relay does not operate?
Check the coil voltage at the socket, polarity if applicable, wiring continuity, socket condition, control signal strength, and whether the relay contacts are loaded within their rated capacity.