ABB O4LE Series Control Relay Modules: O4LE 1KHL015545R0002

Technical Dossier

Product Details And Specifications

ABB O4LE Series: Comprehensive Module Range and Technical Overview

The ABB O4LE series represents a family of auxiliary and control relay modules deployed extensively across global heavy industry verticals, including petrochemical refineries, nuclear power generation facilities, offshore platforms, and continuous-process chemical plants. Manufactured under ABB's SACE and Low Voltage Products division, O4LE relays are engineered to IEC 60947-5-1 standards and are routinely specified in safety-critical switching, motor protection, and interlocking circuits where contact reliability and coil insulation class directly affect plant uptime. Their compact DIN-rail footprint and standardized terminal layout have made them a default choice for panel builders integrating ABB contactors (A-series, AF-series) and circuit breakers (Tmax, SACE Emax) into MCC and PCC assemblies. Installed base across EMEA, Asia-Pacific, and the Americas runs into the millions of units, meaning lifecycle support for older catalog numbers remains a persistent operational requirement for maintenance engineering teams.

The Evolution of O4LE Architecture

The O4LE designation identifies ABB's auxiliary contact block and control relay range within the broader OA/OE/O4 accessory ecosystem. Early-generation O4LE units introduced in the 1990s used silver-alloy bifurcated contacts rated for resistive loads up to 10 A at 240 V AC, with coil voltage options spanning 24 V DC to 240 V AC. These units were designed for direct mechanical coupling to A9–A95 contactor frames, establishing a modular interlocking architecture that persisted across subsequent generations.

Mid-generation revisions introduced gold-flashed contact surfaces for low-energy signal circuits (≤100 mA), expanded the operating temperature range to -25°C / +70°C, and added IEC 60068-2 vibration and shock ratings suitable for marine and rail applications. Coil suppression circuits (RC networks and varistors) were integrated to reduce inductive switching transients on 24 V DC bus systems common in PLC-controlled panels.

Current-generation O4LE modules maintain backward-compatible terminal geometry with legacy A-series contactors while meeting RoHS 2 (2011/65/EU) and REACH compliance requirements. Catalog numbers incorporating the 1KHL prefix (e.g., O4LE 1KHL015545R0002) reflect ABB's unified global ordering system introduced post-2005, replacing earlier regional part numbering schemes. For installations where original O4LE units have reached end-of-production, ABB's CA5 and CAL series auxiliary contact blocks provide the primary migration path, though terminal adapter plates are required in most retrofit scenarios.

O4LE Full Catalog & Functionalities (SKU List)

The following SKUs represent verified catalog entries within the ABB O4LE and directly associated auxiliary relay range. Units are classified by primary function:

Control & Auxiliary Relays

• O4LE 1KHL015545R0002: 4-pole auxiliary relay, 2NO+2NC contact configuration, standard coil, DIN-rail mount
• O4LE 1KHL015545R0001: 4-pole auxiliary relay, 4NO contact configuration, standard coil, DIN-rail mount
• O4LE 1KHL015545R0003: 4-pole auxiliary relay, 4NC contact configuration, standard coil, DIN-rail mount
• O4LE 1KHL015545R0004: 4-pole auxiliary relay, 2NO+2NC, gold-flashed contacts for low-level signal circuits
• O4LE 1KHL015545R0005: 4-pole auxiliary relay, 24 V DC coil, integrated varistor suppression, 2NO+2NC

Contactor-Mounted Auxiliary Contact Blocks

• CA5-10: 1NO front-mount auxiliary contact block, compatible with A9–A75 contactors
• CA5-01: 1NC front-mount auxiliary contact block, compatible with A9–A75 contactors
• CA5-11: 1NO+1NC front-mount auxiliary contact block, A9–A75 frame
• CA5-22: 2NO+2NC front-mount auxiliary contact block, A9–A75 frame
• CAL5-11: 1NO+1NC lateral auxiliary contact block, A9–A95 frame, left or right mount
• CAL5-01: 1NC lateral auxiliary contact block, A9–A95 frame
• CAL18-11: 1NO+1NC lateral auxiliary contact block, A110–A185 frame
• CAL18-01: 1NC lateral auxiliary contact block, A110–A185 frame

Timing & Interface Relays

• CT-AHD.22: On-delay timer relay, 0.05 s–300 h range, 2CO output, 24–240 V AC/DC universal coil
• CT-SDS.22: Star-delta timer relay, adjustable transition delay, 2CO output, panel or DIN-rail mount
• CT-ERD.22: Off-delay timer relay, 0.05 s–300 h, 2CO output, 24–240 V AC/DC
• CR-M024DC2L: Interface relay, 24 V DC coil, 2CO contacts, LED indicator, plug-in base
• CR-M230AC2L: Interface relay, 230 V AC coil, 2CO contacts, LED indicator, plug-in base

Sourcing Hard-to-Find & Obsolete O4LE Parts

ABB has progressively consolidated its auxiliary relay catalog, and several O4LE 1KHL-prefix part numbers have transitioned to limited-availability or end-of-production status. For maintenance teams operating legacy switchgear panels where direct replacement is the only viable option — due to panel space constraints, certification boundaries, or insurance requirements — DriveKNMS maintains a dedicated inventory program for obsolete ABB control components.

Our sourcing process for O4LE units includes cross-referencing ABB's historical catalog archives, direct procurement from decommissioned panel assemblies, and verified new-old-stock (NOS) channels. Each unit is individually cataloged with its original ABB part number, date code (where visible), and contact configuration before entering our inventory. For customers requiring documentation, we provide original ABB datasheet references and, where available, test certificates traceable to the specific production batch.

For plant operators running extended maintenance cycles (5–15 year intervals between major overhauls), we recommend establishing a consignment stock agreement to ensure O4LE availability aligns with scheduled shutdown windows rather than emergency procurement timelines.

Quality Control for the O4LE Range

All O4LE and associated auxiliary relay units processed by DriveKNMS undergo a structured inspection and functional test protocol before dispatch:

• Visual Inspection: Housing integrity check, terminal condition assessment, coil label verification against ordered part number, contact bridge inspection via transparent cover where applicable.
• Coil Resistance Measurement: DC resistance measured and compared against ABB published coil resistance specifications for the applicable voltage rating. Deviation >10% triggers rejection.
• Contact Continuity Test: Each NO and NC contact path tested for continuity in both energized and de-energized states using a calibrated milliohm meter. Contact resistance threshold: <50 mΩ for silver-alloy contacts, <100 mΩ for gold-flashed contacts.
• Insulation Resistance Test: 500 V DC applied between contact circuits and coil circuit. Minimum acceptable insulation resistance: 100 MΩ per IEC 60947-5-1.
• Operational Cycle Test: Minimum 10 energize/de-energize cycles under rated coil voltage, with contact state verified at each cycle via automated test fixture.
• Dimensional Check: Terminal pitch and mounting geometry verified against ABB dimensional drawings to confirm compatibility with target contactor frame or DIN-rail assembly.