XMD4 220VAC — Industrial PCB / Plug-in Power & Signal Relay (4PDT, 220V AC Coil)

Ambiguous P/N · Likely 4PDT 220VAC Coil · Interposing / Signal Relay

The XMD4-220VAC is an industrial-grade relay with a 220V AC coil, most commonly interpreted as a 4PDT (4-pole double-throw) PCB-mount or plug-in signal/power relay. It is widely used as an Allen-Bradley / Omron / Mitsubishi panel-builder equivalent for interposing relay duties inside PLC output cards, control cabinets, motor starters, and machine-tool interfaces. Because the exact datasheet for "XMD4" is not a recognized major-brand catalog number, we list the most likely electrical and mechanical envelope below and ask the buyer to confirm with a photo of the relay plus its existing footprint and any markings on the housing.

Common look-alikes and equivalents held in stock at KOEED include the Omron MY4 220VAC-style 14-pin plug-in relay, the Siemens 3TX7002 style 4PDT coupling relay, and IDEC-style RU / RH 4PDT relays. The XMD4 ships via DHL or FedEx with full tracking and is quoted within 24 hours when you send your inquiry to Moritta@KOEED.COM.

1. Key Technical Specifications & Overview

The XMD4 designation is most consistent with a Chinese / third-party industrial 4PDT relay with a 220V AC coil. The "XMD" prefix is a short, non-standard form used by several OEM manufacturers of Panasonic-style, Omron MY-style, and IDEC RU-style plug-in relays. The trailing "4" almost always indicates 4PDT contact arrangement (4 changeover / Form-C poles), and "-220VAC" indicates the coil voltage. If your relay is actually a 4-pin / 4-contact SPDT or DPDT device, or if the coil is DC, the electrical envelope below will differ — please confirm with us before ordering.

2. Application Scenarios & Where It Fits

A 4PDT 220VAC coil relay sits at the seam between low-current control logic and higher-current field devices. It is a generic building block that appears in almost every factory automation panel, and is the kind of part that KOEED sources for both new build-out and legacy equipment repair. Typical fit-points include:

• PLC output interposing — boosting the switched capacity of an Allen-Bradley MicroLogix / SLC 500 / CompactLogix transistor output, or a Siemens S7-200 / S7-1200 relay output, to drive contactors, solenoid valves, or indicator lamps.
• Signal relay in control panels — replicating a status, a permissive, or a logic decision inside a Schneider Modicon M340 or Mitsubishi MELSEC-Q cabinet.
• Intermediate relay in motor control — between a Yaskawa Σ-7 servo drive fault output and a contactor coil, or as a stop-circuit seal-in for a VFD-protected motor.
• Machine-tool interface — buffer between a Fanuc 0i / 30i CNC I/O Link output and a 24V / 110V / 220V field device on a lathe, mill, or grinder.
• Vision system handshake — passing a trigger or result signal from a KEYENCE CV-5000 / XG-8000 vision controller to a downstream PLC, robot, or reject mechanism.
• Robotics cell E-stop chain — used as one rung in a safety relay chain feeding an Omron NE1A safety controller or equivalent.
• Building-management & HVAC panels — fan, damper, and pump control where the controller outputs 24V DC and the field load is 220V AC.
• Legacy equipment repair — direct swap-in for an aging Omron MY4, IDEC RU4, or Panasonic HC4-H 4PDT that has reached end-of-life in a 1990s-era machine.

3. Integration & Wiring Notes

Wiring a 4PDT 220VAC coil relay looks simple, but the small details determine whether the relay lives for ten years or for ten weeks. The most common mistakes we see in the field are mis-wired coil polarity (for DC-coil variants), missing flyback protection on the contactor coil downstream, and undersized socket wiring. Use the following notes as a checklist when integrating an XMD4 220VAC into your cabinet.

• Coil terminals (A1 / A2): connect to 220V AC L and N. On 14-pin plug-in variants the coil pins are almost always pins 13 and 14; on PCB variants they are the two through-hole pads marked "+" / "−" or "A1" / "A2". The relay is not polarized for AC coils — direction does not matter.
• Contact commons, NO, and NC: the four poles share a common (C), a normally-open (NO), and a normally-closed (NC) terminal each. For 220V AC switched loads, the common is the supply feed and the NO is the switched feed to the load.
• Socket selection: if your relay is the 14-pin plug-in style, match it to a PYF14A / SR3P-05 / 14-pin octal-style DIN-rail socket. Verify the socket's rated voltage (most are 300V AC / 10 A) and that the wire-clamp screws are tight to ~0.8 N·m.
• Snubber & RC network: when switching a contactor or solenoid coil, add an RC snubber (typically 100 Ω + 0.1 µF, 630V) or a varistor (275V AC) across the load coil to suppress back-EMF and extend contact life.
• Separation of power and signal: route 220V AC switched wiring in a separate duct from any 24V DC logic or encoder cables, especially near Yaskawa Σ-7 or Schneider Lexium servo drives, to avoid conducted noise.
• PLC interposing pattern: many Mitsubishi MELSEC and Omron CJ2M installations use one XMD4 pole per PLC output, freeing the remaining three poles for auxiliary status, lamp, and seal-in wiring.
• Dielectric & creepage: maintain at least 8 mm of creepage between the 220V AC coil terminals and any 24V DC wiring on the same socket; on a 14-pin plug-in socket this is provided by the moulding but should be verified after the relay is seated.
• Spare-pole strategy: if the design only uses three of the four poles, leave the unused pole unconnected rather than wiring it back to a common — it gives the relay a margin of life in the field and simplifies troubleshooting.

4. Installation & Commissioning Tips

The XMD4 is a "fit and forget" device once it is wired correctly, but a five-minute commissioning check catches the issues that would otherwise only show up at 03:00 on a production line. Use the checklist below when you bring a new cabinet online or swap a relay on an existing line.

• Visual verification before power-on: confirm pin 1 alignment with the socket key, check that the relay sits flush (no pin overhang), and verify the LED indicator window is facing outward for easy observation.
• Coil voltage measurement: with the panel energised, measure 220V AC across A1 / A2 with a true-RMS multimeter. Anything below ~198V AC risks coil dropout under load.
• Mechanical test with the test button: press the momentary test lever; you should hear a clean click and see the LED change state. If the click is weak or absent, the coil is under-voltage or the relay is damaged in transit.
• Contact resistance check: with the relay de-energised and isolated, measure across each common-to-NO pair — a healthy contact reads below ~50 mΩ. Anything above 200 mΩ indicates pitted or oxidised contacts.
• Functional test from the PLC: force the output bit on for 5 s, watch the LED, listen for the click, and measure the switched 220V AC at the load. Repeat for each pole in use.
• Thermal soak: leave the relay continuously energised for 30 minutes and feel the case with the back of your hand. Warm is normal; hot enough to be uncomfortable suggests an underrated contact or a loose socket screw.
• Documentation in the panel: label the relay with its function (e.g. "K7 — spindle fan interlock") and add a row in the panel legend referencing the BOM line. This is the cheapest reliability win on a plant floor.
• Spare inventory: keep at least one spare XMD4-220VAC plus one spare 14-pin socket in the panel drawer. A 4PDT relay swap takes less than a minute and avoids a line stop that costs more in 30 minutes than a year of spare inventory.

5. Procurement, Warranty & Lead Time

KOEED sources the XMD4 220VAC relay through our China Sourcing Company supply chain, with multi-batch QC and shipment via DHL or FedEx worldwide. Because the part number is ambiguous (the "XMD" prefix is not a major-brand catalog number), the procurement process is slightly different from a confirmed-brand part — please send the information listed below so we can match the exact relay you need on the first shipment.

• What to send: (1) a clear photo of the relay (top + side), showing the markings on the housing, the pin count, and the LED / test-button layout; (2) a photo of the existing footprint or socket (so we can match pin-out); (3) any datasheet PDF or page snapshot you have; (4) the project context (machine model, panel builder, country of installation).
• What we confirm: contact arrangement (4PDT / DPDT / SPDT), coil voltage (AC vs DC, exact voltage), contact rating (5 A / 10 A), mounting (PCB vs 14-pin plug-in), and any approvals required by your end customer.
• Quote turnaround: within 24 hours on business days, sent to your inbox. The quote includes part specification, lot origin, lead time, and shipping options (DHL / FedEx).
• Warranty: 12-month replacement warranty against manufacturing defect, in line with our standard return policy. Units are inspected for coil resistance, contact resistance, dielectric strength, and mechanical action before shipment.
• Lead time: in-stock lots ship within 2–3 business days via DHL or FedEx; factory orders for unusual variants typically 7–14 days, depending on coil voltage and quantity.
• BOM quotation: if you are also sourcing the socket, the snubber, the wiring duct, or the surrounding Allen-Bradley / Siemens / Mitsubishi / Omron / Fanuc / Schneider / Yaskawa / Panasonic / KEYENCE parts in the same cabinet, send the full list and we will quote the lot in a single email.
• Cross-reference on request: if you have a known-equivalent part (e.g. an Omron MY4-02 220VAC, an IDEC RU4S-A220, or a Finder 55.34), tell us and we will confirm functional and mechanical compatibility before you order.