Schneider Electric LV432693 Spare for Masterpact NT/NW

Schneider Electric LV432693 Spare for Masterpact NT/NW Automation

The Schneider Electric LV432693 is an original MICROLOGIC 6.0A electronic trip unit designed for Masterpact NT and NW series air circuit breakers (ACBs). As a critical protection and measurement component within medium-voltage distribution and industrial power control systems, the LV432693 governs overload, short-circuit, earth fault, and ground fault protection functions. For maintenance engineers managing aging switchgear or executing planned shutdowns, having a verified original spare on hand is the single most effective strategy to minimize unplanned downtime and restore system availability within hours rather than days.

Whether you are conducting routine control cabinet inspections, responding to a nuisance trip event, or executing a lifecycle replacement on an aging Masterpact NT/NW frame, the LV432693 is a plug-and-replace solution that preserves your existing protection settings and communication architecture. This unit is sourced as an original Schneider Electric component, inspected, and tested before shipment to ensure full functional compliance with factory specifications.

Spare Maintenance Table

Maintenance Planning for Continuous Operation

When replacing the LV432693 MICROLOGIC 6.0A trip unit during a planned or emergency maintenance window, a thorough inspection of the surrounding electrical circuit is essential to prevent repeat failures and ensure system integrity. Maintenance engineers should treat this replacement as an opportunity to audit the full ACB assembly and its upstream/downstream components.

Begin by verifying the condition of the Masterpact NT/NW cradle and draw-out mechanism — worn racking contacts or damaged shutters can introduce resistance and cause erratic trip behavior even after a trip unit replacement. Inspect the BCM ULP communication module (if installed) for firmware version compatibility with the new trip unit, as mismatched firmware can cause Modbus communication faults on the SCADA or BMS network.

Check the MicroLogic A9 auxiliary power supply module or any 24 VDC auxiliary supply feeding the trip unit — a degraded power supply is a common root cause of false earth fault alarms. Inspect all CT (current transformer) connections on the ACB for corrosion or loose terminals, as poor CT contact directly affects the accuracy of Ir and Ig protection thresholds.

For panels with downstream motor control centers, verify the condition of TeSys D or TeSys K contactors and associated LR2 or LR9 thermal overload relays — these components share the same fault-clearing duty cycle and often degrade in parallel with the ACB trip unit. If the panel includes Vigirex RH series residual current relays for earth leakage protection, confirm their test function and sensitivity settings remain within specification.

Review the terminal blocks and busbar connections within the switchgear compartment for signs of thermal discoloration or micro-arcing, which indicate sustained overload conditions that may have contributed to the original trip unit failure. Where Sepam series protection relays are used in parallel protection schemes, cross-check relay coordination settings after the LV432693 is reinstalled to ensure selectivity is maintained.

Finally, if the installation includes a PowerLogic PM series power meter or EcoStruxure Panel Server for energy monitoring, re-synchronize the metering configuration after replacement to restore accurate kWh and demand data logging. Keeping a documented spare inventory that includes the LV432693, a BCM ULP module, and a set of ACB auxiliary contacts ensures your team can execute a full ACB restoration within a single maintenance shift.

Site Replacement Workflow

Step 1 — Isolation & Lockout: Open and rack out the Masterpact NT/NW breaker to the isolated position. Apply LOTO (Lockout/Tagout) per site safety procedures. Confirm zero energy state with an approved voltage tester on both line and load terminals.

Step 2 — Trip Unit Removal: Press the release tabs on the front face of the existing MICROLOGIC trip unit and slide it forward out of the breaker chassis. Note the existing protection settings (Ir, Isd, Ii, Ig) displayed on the LCD before removal — photograph or record these values for reconfiguration.

Step 3 — LV432693 Installation: Align the LV432693 with the breaker chassis guide rails and slide it firmly into position until the retention tabs click. The plug-in design requires no tools and ensures correct CT and communication connector seating automatically.

Step 4 — Settings Restoration: Power up the trip unit and navigate the LCD menu to restore Ir, Isd, Ii, and Ig settings to the previously recorded values. If a BCM ULP module is connected, verify Modbus address and baud rate match the existing network configuration.

Step 5 — Functional Test: Use the MICROLOGIC test button to perform a local trip test. Confirm the breaker trips and resets correctly. If a Modbus network is present, verify the trip unit appears online in the SCADA or EcoStruxure system before returning the breaker to service.

Step 6 — Documentation: Record the replacement in the equipment maintenance log, including the new unit serial number, date of installation, and restored protection settings. Update the spare parts inventory to trigger reorder of a replacement LV432693 for future readiness.

Spare Parts Support FAQ

Q1: Is the LV432693 a direct plug-in replacement for all MICROLOGIC 6.0A units in Masterpact NT and NW breakers?
Yes. The LV432693 is the standard MICROLOGIC 6.0A trip unit for Masterpact NT (400–800A) and NW (800–6300A) frames. It is a direct plug-in replacement for any existing MICROLOGIC 6.0A unit in these frames without requiring breaker disassembly or rewiring. Always confirm the frame rating and existing trip unit model number before ordering to ensure full compatibility.

Q2: What pre-shipment testing is performed on the LV432693?
Each unit undergoes functional verification including power-up self-test, LCD display check, protection threshold response, and communication port continuity before shipment. Units are shipped with original packaging and documentation where available. A 12-month warranty covers manufacturing defects and functional failures under normal operating conditions.

Q3: How should the LV432693 be stored as a long-term spare?
Store in original anti-static packaging in a dry, temperature-controlled environment (0°C to +40°C, <85% RH non-condensing). Avoid storage near strong magnetic fields or high-vibration areas. Inspect annually for any signs of physical damage or connector corrosion. For critical facilities, maintain at least one LV432693 per installed Masterpact NT/NW ACB as a minimum spare holding.

Q4: Can the LV432693 be used to upgrade from a lower MICROLOGIC version (e.g., 2.0A or 5.0A)?
The MICROLOGIC 6.0A adds earth fault (Ig) and power/energy measurement functions not present in 2.0A or 5.0A variants. While the physical form factor is compatible with the same Masterpact NT/NW chassis, upgrading from a lower version requires reconfiguration of protection settings and, if Modbus communication is used, updating the SCADA register map to reflect the expanded measurement data set. Consult the Masterpact NT/NW user manual or contact our technical team before proceeding with a cross-version upgrade.

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