Schneider RXM4AB2BD — 24VDC 4PDT Relay Specs & Socket Guide

By Abdullah Zahid
13 min read
Schneider Electric RXM4AB2BD 4PDT 24VDC miniature plug-in relay with LED indicator for automation panel mounting

Schneider RXM4AB2BD — Miniature Plug-In Relay, Harmony Electromechanical Relays, 6A, 4CO, with LED, Lockable Test Button, 24V DC

If you are specifying a compact 4-pole changeover relay for a 24VDC automation panel and you have landed on the Schneider RXM4AB2BD, you are likely at the final confirmation stage: validating the contact rating against your load voltage, confirming socket compatibility, and checking availability before raising the purchase order. This article gives you every specification and ordering detail you need to make that call with confidence. The RXM4AB2BD is a socket-mounted miniature electromagnetic relay with a 24VDC coil, 4PDT contact configuration rated at 6A at 277VAC, an integrated LED indicator, and a lockable test button — all in a 40x27x21mm footprint designed for tight panel layouts.

If you have already confirmed this is the right part, check current pricing and availability at LeadTime.ca — ships worldwide.

Who Should Buy the RXM4AB2BD — and Who Shouldn't

The RXM4AB2BD is the right relay for automation engineers and panel builders who need a verified 4-pole changeover relay on a standardized 24VDC control platform. Confirm these criteria match your application before ordering:

  • Your control power supply is 24VDC — this relay does not support 24VAC, 120VAC, or 240VAC coil inputs under any configuration
  • Your load current does not exceed 6A at 277VAC, or 8A at 28VDC
  • Your application requires 4 changeover pairs (4PDT) for complex multi-output switching logic
  • You have a compatible RXZE series socket on your bill of materials — the relay is not DIN-mountable without it
  • Your panel environment is indoor industrial, with IP40 protection sufficient for the installation
  • Operating temperature stays within -40 to +55 degrees C

If your load exceeds 6A at AC voltage, the RXM3AB2BD with its 8A contact rating at 277VAC is the correct alternative. If you need only 2 poles, the RXM2AB2BD reduces footprint further. If your control supply is AC-only, you must move to the Harmony RX2 series — the RXM4AB2BD will not function on AC coil voltage.

On this page:

What the RXM4AB2BD Actually Does in a Control Panel

The RXM4AB2BD sits at the interface between a low-power logic circuit and the higher-current load circuits that do physical work in a machine or building system. A PLC discrete output, a thermostat signal, or a sensor relay energizes the 24VDC coil — which draws only 10mA at 0.9W — and the relay switches up to four independent load circuits simultaneously through its 4PDT contact arrangement. Each contact pair handles up to 6A at 277VAC or 8A at 28VDC, covering a broad range of typical automation loads including motor starter coils, solenoid valves, fan contactors, and indicator circuits.

The integrated green LED confirms coil energization without requiring a separate indicator module. The orange mechanical status flag provides a visual confirmation of contact state that is readable even when panel lighting is poor. The lockable test button allows technicians to manually hold the relay in the energized position during commissioning — a feature that eliminates the need for a temporary jumper on the coil terminals and significantly speeds up wiring verification. With a maximum switching capacity of 1500VA and a rated duty cycle of up to 1200 cycles per hour under load, the RXM4AB2BD is suited to frequent-cycle applications including conveyor sequencing, zone switching, and staged HVAC control.

Typical System Architecture

The RXM4AB2BD occupies the interface layer between the controller output and field devices in a standard automation cabinet. Here is where it typically sits in the signal chain:

  • PLC or controller provides a 24VDC discrete output signal to the relay coil circuit
  • RXM4AB2BD coil energizes, switching all four contact pairs simultaneously
  • RXZE socket base (ordered separately) provides the physical DIN rail mount and terminal connections for both coil and contact wiring
  • Contact outputs switch load circuits — motor starter coils, contactor coils, solenoid valves, or indicator lamps — at up to 6A at 277VAC
  • Optional RXZE1SRE suppression module installed on the socket protects contacts when switching inductive loads

Where Engineers Deploy the RXM4AB2BD

In automation control panels, the RXM4AB2BD most commonly appears as a PLC interface relay — converting a low-current PLC output into a contact closure capable of driving motor starter coils or contactors at line voltage. The 4PDT configuration is particularly useful here because a single relay can simultaneously control start logic, a brake circuit, a directional indicator, and an interlock signal from one coil command.

HVAC engineers use the RXM4AB2BD for zone control and multi-stage compressor staging, where the 24VDC thermostat or building automation controller signal must switch multiple fan and compressor circuits. The relay's -40 to +55 degrees C operating range accommodates both mechanical room and rooftop unit applications without derating.

In conveyor and packaging machinery, the relay handles sequencing tasks — triggering start signals, brake release, direction commands, and indicator lamps from a single PLC output — where the 4-pole configuration eliminates the need to stack two 2-pole relays, reducing panel footprint and wiring complexity.

Motor starter bypass circuits use the RXM4AB2BD to manage star-to-delta transition logic, where isolated contact pairs control independent contactor coils through the acceleration sequence. Emergency stop and safety circuit designs use it to provide independent control paths with physical contact separation, though designers specifying safety-rated circuits should verify the relay against their specific SIL requirements with the manufacturer documentation.

Application Typical Deployment
PLC Interface Relay Bridges 24VDC PLC output to 120VAC or 277VAC motor starter coil
HVAC Zone Control Switches 24VDC thermostat signal to multi-stage compressor and fan contactors
Conveyor Sequencing Controls start, brake, direction, and indicator lamp from single control signal
Motor Starter Bypass Manages star-to-delta transition logic with isolated contact pairs per contactor
Building Automation Interfaces 24VDC BAS controller output to line-voltage HVAC and lighting loads
Emergency Stop Logic Provides independent 4-pole contact isolation in multi-path safety circuits

Specifications That Drive the Purchase Decision

Specification Value
Coil Voltage 24VDC only — no AC variant available
Coil Current 10mA
Coil Power Consumption 0.9W (1.2VA)
Contact Configuration 4PDT (4 changeover pairs)
Contact Rating (AC) 6A at 277VAC (resistive load)
Contact Rating (DC) 8A at 28VDC
Maximum Switching Capacity 1500VA / 168W
Body Dimensions 40 x 27 x 21mm
Operating Temperature -40 to +55 degrees C
IP Rating IP40 (IEC 60529)

Full technical specifications are available on the product page at LeadTime.ca.

RXM4AB2BD vs. RXM3AB2BD vs. Alternatives: Which Relay Do You Need?

Model Coil Poles Contact Rating (AC) Key Difference Typical Use
Schneider RXM2AB2BD 24VDC 2PDT 6A at 277VAC 2 poles only; smaller footprint Simple dual-output logic
Schneider RXM3AB2BD 24VDC 3PDT 8A at 277VAC 3 poles; higher amperage contacts 3-phase or triple switching
Schneider RXM4AB2BD 24VDC 4PDT 6A at 277VAC 4 poles; this model Complex multi-output control
Crouzet CoDL-402 24VDC 4PDT 6A at 250VAC Compact alternative; different socket ecosystem European supply chain sourcing
Finder 46 Series 24VDC 4PDT 6A at 250VAC Wider availability; slimmer design General-purpose industrial use
ABB CR-P024DC4 24VDC 4PDT 10A at 277VAC Built-in surge protection; higher contact rating Inductive load switching without external suppressor

If your load current exceeds 6A at AC voltage, the RXM3AB2BD's 8A contact rating is the correct step up — and if you are switching inductive loads without wanting to add an external suppression module, the ABB CR-P024DC4 includes built-in surge protection as standard. Confirm current availability and pricing at LeadTime.ca before finalizing your BOM.

Expert Verdict: Is the RXM4AB2BD the Right Relay for Your Build?

The RXM4AB2BD earns a straightforward recommendation for automation engineers and panel builders working within the Harmony ecosystem on a standardized 24VDC control platform. Its 4PDT configuration handles the kind of multi-circuit switching logic — start, brake, direction, interlock — that would otherwise require stacking two 2-pole relays and consuming nearly twice the panel real estate. The 0.9W coil power consumption is a genuine advantage in control panels with a lean 24VDC budget, and the integrated LED plus lockable test button measurably reduce commissioning time by eliminating the need for separate diagnostic modules. At rated duty of up to 1200 cycles per hour under load and a maximum switching capacity of 1500VA, this relay covers the majority of PLC interface, HVAC staging, and conveyor sequencing applications without performance compromise.

There are three situations where this relay is the wrong choice and a different model should be specified. First, if your control power is AC-only — even at 24VAC — the RXM4AB2BD will not function; the Harmony RX2 series is the correct alternative. Second, if your switching load regularly exceeds 6A at AC voltage, the RXM3AB2BD's 8A contacts are the appropriate upgrade, and attempting to push the RXM4AB2BD beyond its 6A AC rating will cause premature contact failure. Third, if your application requires a latching or memory function, this relay family does not support it — you will need to source from a different product family entirely.

From a procurement standpoint, the RXM4AB2BD is a well-stocked, competitively priced part available through multiple authorized channels worldwide. The one sourcing discipline that separates a smooth commissioning from a project delay is this: always order the RXZE socket simultaneously. Relay and socket are separate line items, and ordering one without the other is the most frequently reported ordering mistake with this product family. A specialist distributor who stocks both and ships them together eliminates that risk entirely. View current pricing and confirm socket availability at LeadTime.ca — we ship worldwide.

For volume pricing or to confirm lead time before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

What Engineers Need to Know Before Ordering the RXM4AB2BD

Because community discussion specific to this model number is limited in publicly indexed forums, the guidance in this section comes from the documented field patterns and specification details that experienced engineers and specialist distributors consistently flag before a purchase order is placed. These are not edge cases — they are the three points that separate a clean installation from a commissioning delay or a field failure.

The socket-mounting requirement is the most critical point to internalize before ordering. The RXM4AB2BD relay body has Faston quick-connect terminals on its base — it does not mount independently to a DIN rail. It requires an RXZE series socket base, which is a separate catalog item. The socket is available in three terminal configurations: screw clamp (RXZE2S114M), push-in (RXZE2P114M), and screw connector (RXZE2C114M). Your choice of socket terminal type must match your panel's existing wiring infrastructure. First-time buyers who receive the relay without having ordered the socket face a project hold of two to three days while the socket ships separately — a completely avoidable delay if both line items are on the original purchase order.

The second recurring issue is inductive load protection. The RXM4AB2BD has no internal transient suppression. When it switches inductive loads — motor coils, contactor coils, solenoid valves — the voltage spike generated at contact opening can cause contact erosion and welding over time. The RXZE1SRE surge suppression module clips directly onto compatible RXZE sockets and provides the required protection without external components. If your application switches any inductive load, include the RXZE1SRE on your BOM alongside the relay and socket. The third point engineers must verify is coil voltage: 24VDC is non-negotiable. Facilities with mixed or legacy AC control systems where 24VAC is available at the panel must not substitute this relay without verifying the supply is DC. A voltmeter set to AC/DC measurement is the definitive check before wiring the coil terminals.

Wiring and Installation Overview

The following points summarize the key requirements for installing the RXM4AB2BD. For complete wiring diagrams and step-by-step procedures, refer to the Schneider Electric installation documentation for the RXM relay series and RXZE socket family.

  • Insert the RXM4AB2BD into the RXZE socket base with the keyed connector aligned — the relay clicks into the locked position when fully seated
  • Connect 24VDC with correct polarity to the coil terminals on the socket — the green LED illuminates immediately upon successful coil energization; no LED response indicates incorrect polarity or supply absence
  • Connect load circuits to the socket contact terminals — verify load current and voltage do not exceed 6A at 277VAC or 8A at 28VDC before applying power
  • If switching inductive loads (motor coils, contactor coils, solenoids), install the RXZE1SRE suppression module or an external varistor across the load — the relay provides no internal surge suppression
  • Use the lockable test button to manually verify contact closure during commissioning — press to switch contacts, flip the green tab to lock the position, and confirm the orange mechanical flag changes state before releasing

Socket and Accessory Requirements

The RXM4AB2BD relay requires the following accessories to be fully installed and protected. None of these are included with the relay body and must be ordered as separate line items.

  • RXZE2S114M — RXZE socket with screw clamp terminals; standard configuration for most panel wiring
  • RXZE2P114M — RXZE socket with push-in terminals; faster wiring assembly and reduced installation time
  • RXZE2C114M — RXZE socket with screw connector terminals; modular wiring with fixed terminal blocks
  • RXZE1SRE — Surge suppression module; clips directly onto compatible RXZE socket; required when switching inductive loads to prevent contact erosion and premature failure

Wrong-Part Prevention Checklist

Before submitting your purchase order for the RXM4AB2BD, verify every item on this checklist. These are the confirmed ordering errors that cause installation delays and field failures with this relay family.

  1. Verify 24VDC coil voltage only - relay does not support 24VAC, 120VAC, or 240VAC coil inputs
  2. Confirm RXZE socket is ordered separately - relay alone is not DIN-mountable without socket accessory
  3. Check contact rating is 6A at your application voltage (not 8A at any voltage; 8A limited to 28VDC only)
  4. Ensure 4PDT (4 changeover pairs) is the required configuration - if only 2 poles needed, RXM2AB2BD is correct alternative
  5. Specify terminal type when ordering RXZE socket: screw clamp, screw connector, or push-in terminal options
  6. Do not assume internal surge protection - external varistor or transient suppression required if switching inductive loads

If any item on this checklist raises a question about your specific application, contact the LeadTime.ca team before ordering — confirming the right relay and socket combination takes minutes and prevents days of delay.

Frequently Asked Questions

Does the RXM4AB2BD include the RXZE socket, or does it need to be ordered as a separate part?

The RXZE socket is a separate catalog item and is not included with the RXM4AB2BD relay. The relay body uses Faston quick-connect terminals on its base and requires an RXZE socket for DIN rail mounting and terminal connection. You must select the correct socket terminal type for your panel: RXZE2S114M for screw clamp, RXZE2P114M for push-in, or RXZE2C114M for screw connector. Always order both part numbers on the same purchase order to avoid installation delays.

Can the RXM4AB2BD be wired with a 24VAC control signal instead of 24VDC?

No. The RXM4AB2BD coil is rated for 24VDC only. Applying 24VAC or any AC coil voltage to this relay will result in non-responsive or erratic operation — the relay will not energize correctly. If your control power supply is AC, you must specify an alternative relay family such as the Harmony RX2 series, which supports AC coil voltages. Always measure your control supply with a voltmeter on the DC setting to confirm voltage type before ordering.

Is the 6A contact rating the same for both AC and DC loads, or does it change by voltage?

The contact rating is voltage-dependent. The RXM4AB2BD is rated at 6A at 277VAC for AC resistive loads, and 8A at 28VDC for DC loads. These are not interchangeable: specifying this relay for a 10A AC load or applying DC current beyond the 28VDC maximum will cause premature contact failure or contact welding. If your AC load current exceeds 6A, the RXM3AB2BD with its 8A AC contact rating is the correct alternative.

What happens if I switch inductive loads (motor coils, contactor coils) without adding surge protection?

The RXM4AB2BD provides no internal transient suppression. Switching inductive loads generates voltage spikes at the moment of contact opening, which causes contact erosion and can lead to contact welding — where the contacts fuse together and the relay fails to open. The RXZE1SRE suppression module clips directly onto compatible RXZE sockets and provides the required protection. An external varistor across the inductive load is an acceptable alternative. Either approach should be treated as mandatory, not optional, when switching inductive loads.

What is the difference between the RXM4AB2BD and the RXM3AB2BD, and how do I choose?

The RXM4AB2BD has 4 changeover contact pairs (4PDT) rated at 6A at 277VAC, while the RXM3AB2BD has 3 changeover pairs (3PDT) rated at 8A at 277VAC. If your application requires switching four independent circuits simultaneously, the RXM4AB2BD is correct. If you need only three circuits but require higher contact current per pole, the RXM3AB2BD is the right choice. Both use 24VDC coil voltage and are compatible with the RXZE socket family.

How does the lockable test button work, and what does it confirm during commissioning?

The lockable test button on the RXM4AB2BD allows a technician to manually force the relay contacts into the energized position without applying a coil signal. Pressing the button momentarily switches all four contact pairs. Flipping the green tab upward locks the contacts in the switched position until released — this allows the technician to verify downstream load circuits without needing a live control signal. The orange mechanical indicator flag provides a visual confirmation of contact state. This feature eliminates the need for temporary coil jumpers during commissioning and speeds up contact wiring verification considerably.

Why Order From LeadTime.ca

  • Ships worldwide — no regional restrictions on orders for the RXM4AB2BD relay or RXZE socket accessories
  • Stocks both relay and socket accessories, allowing a single purchase order to cover all required components without fulfillment gaps
  • Specialist team available to confirm relay-socket compatibility and terminal type selection before your order is placed
  • Volume pricing available for panel builders and OEMs — contact directly for project quantities
  • Sourcing support for hard-to-find parts, accessories, and replacement components across the Harmony RXM series

At-a-Glance Summary

  • Coil voltage: 24VDC only — no AC variant; coil draws 10mA at 0.9W
  • Contact configuration: 4PDT (4 changeover pairs) rated at 6A at 277VAC and 8A at 28VDC
  • Maximum switching capacity: 1500VA / 168W
  • Rated duty: up to 1200 cycles per hour under load; up to 18000 cycles per hour no-load
  • Body dimensions: 40 x 27 x 21mm — socket-mounted via RXZE series (ordered separately)
  • Operating temperature: -40 to +55 degrees C; IP40 per IEC 60529
  • Integrated features: green LED indicator, orange mechanical status flag, lockable test button
  • Compliance: CE, CSA C22.2, UL 508, WEEE
  • Manufacturer warranty: 18 months from purchase
  • RXZE socket must be ordered separately — specify terminal type (screw clamp, push-in, or screw connector)
  • External surge suppression (RXZE1SRE or varistor) required when switching inductive loads

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