Schneider LV429407 Undervoltage Release — Specs & Buying Guide

By Abdullah Zahid
15 min read
Schneider LV429407 MN undervoltage release coil for Compact NSX circuit breakers 220-240VAC industrial control panel

Schneider LV429407 Undervoltage Release MN, ComPact NSX, 220/240VAC 50/60Hz, 208/277VAC 60Hz — Specifications, Compatibility and Alternatives

If you are sourcing a voltage release coil for a Compact NSX, PowerPact Multistandard, or EasyPact CVS circuit breaker and need MN-type undervoltage functionality, the Schneider LV429407 is the accessory that monitors control circuit voltage and automatically opens the breaker when voltage drops below 35% of rated value. It is UL Listed, CSA Certified, and compliant with IEC 60947-2, covering both 220/240VAC 50/60Hz and 208-277VAC 60Hz control circuits in a single part number. The only thing standing between a correct installation and a costly mistake is voltage rating confirmation before the order ships.

If you have already confirmed this is the right part, check current pricing and availability for the LV429407 at LeadTime.ca — ships worldwide.

Who Should Buy the LV429407 — and Who Should Not

The LV429407 is the right choice for engineers and technicians who need MN-type undervoltage protection on a confirmed-compatible Schneider circuit breaker. This part is appropriate if all of the following apply to your installation:

  • Your circuit breaker is a Compact NSX (frame size 100, 160, 250, 400, or 630 A), PowerPact Multistandard, or EasyPact CVS — confirmed from the breaker nameplate
  • Your control circuit voltage is 220-240VAC at 50/60Hz or 208-277VAC at 60Hz — measured at the installation point, not assumed from facility drawings
  • Your application requires MN-type coil function (automatic opening when control voltage is lost or drops below threshold) rather than MX-type shunt release
  • Your installation accepts screwless spring terminal connections for control circuit wiring
  • Your project specification requires IEC 60947-2 compliance and UL Listed / CSA Certified components

If your circuit breaker is from a different Schneider family (C120, Masterpact, or TeSys), if your control voltage falls outside both rated ranges, or if you already have an MX coil installed in the only available coil slot, the LV429407 is not the correct part — confirm the right variant with a distributor before ordering.

On this page:

What the LV429407 Actually Does in a Live System

The LV429407 is an MN-type undervoltage release coil — a plug-in cartridge accessory that mounts into the dedicated coil slot on compatible Compact NSX circuit breakers. Its function is straightforward but safety-critical: it holds the circuit breaker closed only while control voltage is present above the threshold. The moment control circuit voltage drops below 35% of the rated value, the coil releases its hold and the breaker trips open automatically, isolating the load without requiring any operator action or PLC logic to intervene.

This behavior is fundamentally different from a standard overcurrent trip or a shunt release (MX coil). The MN coil is a fail-safe device — loss of voltage is the trigger, not the presence of a trip signal. That distinction matters enormously when wiring emergency stop circuits, load shedding schemes, or remote isolation stations. If the control cable is cut, if the upstream supply fails, or if the emergency stop button breaks the control voltage supply, the LV429407 will open the breaker. A shunt release (MX) would not respond to that same condition.

The LV429407 covers two voltage ranges in a single part number: 220-240VAC at 50/60Hz for European and many Asian facilities, and 208-277VAC at 60Hz for North American control circuits. IEC 60947-2 compliance confirms the trip threshold and performance characteristics meet recognized international standards, while the UL Listed and CSA Certified marks satisfy contractual requirements for installations in the United States and Canada. The screwless spring terminals accept standard control wire gauges and eliminate the torque-sensitive connections that cause intermittent faults in vibration-prone environments.

Where the LV429407 Sits in Your Control System Architecture

The LV429407 sits between your control voltage supply and the circuit breaker's internal release mechanism — it is the component that translates a voltage condition into a mechanical trip event.

  • Control voltage source (facility 220-240VAC or 208-277VAC supply) feeds the LV429407 coil terminals through the control circuit
  • Emergency stop button, remote shutdown relay, or load shedding contactor interrupts or maintains the control voltage supply to the coil
  • LV429407 coil monitors that voltage continuously and holds the Compact NSX breaker in the closed position while voltage is above 35% of Un
  • When control voltage drops below threshold — whether from deliberate E-stop actuation, a grid disturbance, or a wiring fault — the coil releases and the Compact NSX breaker opens immediately
  • Downstream load (motor, HVAC system, process equipment, or distribution panel) is de-energized until an operator manually resets and closes the breaker

Typical Applications and Industries for the LV429407

Emergency stop circuits represent the most common application. The LV429407 is wired so that the control voltage supply to the coil passes through one or more E-stop buttons. Breaking that circuit — from any station in a plant — trips the main or section breaker instantly, without relying on a PLC or relay to generate a shunt trip signal. This is particularly valuable in water treatment facilities, chemical processing, and food and beverage plants where hard-wired emergency isolation is a code or insurance requirement.

Remote opening from multiple field locations is another primary use case. In large manufacturing facilities, mining operations, or utilities, operators need to isolate sections of a distribution system from multiple points. Rather than running mechanical linkages or requiring personnel to physically reach the breaker handle, the LV429407 enables any break in the control voltage loop to initiate isolation — clean, logged, and auditable.

Load shedding during grid disturbances is a third well-established deployment. When facility incoming voltage sags severely during a grid event, the LV429407 will open non-critical breakers if their control voltage is derived from the monitored supply. This prevents downstream equipment damage from prolonged undervoltage conditions and allows controlled restart sequencing once the grid recovers.

Maintenance isolation and integration with soft-start or VFD systems round out the common deployment picture. The LV429407 provides a hard-wired trip independent of any programmable controller, which satisfies safety requirements in facilities where a PLC fault must not prevent equipment de-energization.

Application Typical Deployment
Emergency stop circuit Control voltage routed through E-stop button chain; any break trips Compact NSX breaker immediately
Remote multi-station shutdown Multiple remote field stations interrupt shared control voltage loop to isolate distribution section
Load shedding on grid disturbance Control voltage derived from monitored bus; voltage sag below 35% Un opens non-critical feeders automatically
Maintenance isolation (confined/elevated locations) Remote de-energization without physical access to breaker handle in difficult-access locations
VFD and soft-start backup trip Hard-wired control voltage break provides independent trip path if PLC or drive fault disables normal shutdown logic
HVAC and building management systems BMS output relay interrupts coil control voltage on fire alarm or emergency signal to isolate HVAC distribution

LV429407 Key Specifications and Variant Comparison

Specification LV429407 Value
Coil Type MN (Undervoltage Release)
Rated Control Voltage (Primary) 220-240VAC, 50/60Hz
Rated Control Voltage (Secondary) 208-277VAC, 60Hz only
Trip Voltage Threshold Below 35% of rated voltage (Un)
Control Circuit Type AC (direct voltage monitoring, not pulsed DC)
Terminal Connection Type Screwless spring terminal
Compatible Frame Sizes NSX 100, 160, 250, 400, 630 A
Protection Standard IEC 60947-2
Certifications UL Listed / CSA Certified
Coil Positions Per Breaker 1 MN or 1 MX — not stackable; only one type per breaker

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

The MN versus MX decision is the most consequential variant choice for this product family. The table below summarizes the critical difference:

Feature LV429407 (MN — Undervoltage Release) MX Type (Shunt Release)
Trip Trigger Loss of or drop in control voltage (below 35% Un) Application of a voltage pulse to coil terminals
Fail-Safe Behavior Yes — trips on loss of power (fail-open) No — requires active voltage signal to trip
Emergency Stop Wiring Direct series wiring in control voltage loop Requires relay or PLC output to generate trip pulse
Breaker Family Compact NSX, PowerPact Multistandard, EasyPact CVS Compact NSX, PowerPact Multistandard, EasyPact CVS
Can both be installed simultaneously? No — only one coil type (MN or MX) per breaker
Certification IEC 60947-2, UL Listed, CSA Certified IEC 60947-2 (verify certifications on specific MX model)

If your application requires the breaker to trip on a positive command signal rather than on voltage loss, the MX shunt release is the correct type — contact the LeadTime.ca team to confirm the correct MX variant for your breaker model and voltage.

Expert Verdict: Is the LV429407 Right for Your Project?

The LV429407 is the correct and specific choice for any engineer or technician who needs MN-type undervoltage release functionality on a Compact NSX, PowerPact Multistandard, or EasyPact CVS circuit breaker. Its IEC 60947-2 compliance is not a checkbox item — it defines the trip threshold at 35% of rated voltage (Un) and the performance envelope that safety system designers and AHJs rely on. The UL Listed and CSA Certified marks make it the only compliant option for many North American industrial and commercial specifications. If you are replacing a failed MN coil in an existing Compact NSX installation, this is a direct drop-in and the decision is straightforward. If you are specifying for a new panel, the dual voltage rating (220-240VAC 50/60Hz and 208-277VAC 60Hz) in a single part number simplifies inventory management across facilities with different supply standards.

Where the LV429407 reaches its limits is equally clear. It will not fit or function in any Schneider breaker family outside Compact NSX, PowerPact Multistandard, and EasyPact CVS — attempting to install it in a C120 or Masterpact will result in a physical or functional mismatch. If your control circuit voltage falls outside both rated ranges, a different voltage release model must be sourced. And if the coil slot on your breaker already has an MX coil installed, you cannot add the LV429407 without first removing the MX unit — only one coil type per breaker is supported. Buyers who need a positive-command trip rather than a fail-safe voltage-loss trip should evaluate MX shunt release options instead.

From a procurement standpoint, the LV429407 is stocked by specialist electrical distributors worldwide and is generally available with short lead times under normal conditions — though emergency maintenance situations can put pressure on local stock. Sourcing through a distributor with trained technical staff matters here because voltage rating confirmation before shipment eliminates the most common and costly ordering mistake. LeadTime.ca ships worldwide and can support both single-unit maintenance orders and bulk panel-build quantities. Check current availability and pricing for the LV429407 at LeadTime.ca before your installation window opens.

For volume pricing, lead time confirmation, or help verifying the correct coil type before committing to a panel build, contact the LeadTime.ca team directly — we ship worldwide.

What Engineers Need to Know Before Ordering the LV429407

Because the LV429407 is a specialized B2B component procured through direct distributor relationships rather than general retail channels, publicly available community discussions on this specific part number are sparse. What exists instead is a well-documented pattern of ordering and installation mistakes that specialist distributors encounter regularly — and that the right distributor relationship can prevent entirely.

The most consequential pre-order step is voltage measurement, not voltage assumption. The LV429407 covers 220-240VAC at 50/60Hz and 208-277VAC at 60Hz, but the correct operating range for your installation must be confirmed by measuring the actual control circuit voltage at the panel with a multimeter. Facility nominal voltage and electrical drawings do not always reflect the true voltage at the coil connection point, particularly in older installations or facilities that have undergone supply upgrades. A mismatch between coil rating and actual control voltage results in incorrect trip threshold calibration — the breaker may fail to open at the intended threshold or may nuisance-trip under normal operating conditions. Neither failure mode is acceptable in a safety-critical circuit.

The MN versus MX coil confusion is the second most frequently encountered issue. Both coil types occupy the same physical slot on a Compact NSX breaker, and both are described as voltage release accessories — but their operating logic is opposite. The MN coil (LV429407) opens the breaker on loss of voltage; the MX shunt release opens the breaker on application of voltage. Ordering the wrong type requires a full coil removal and replacement on-site, which in a time-critical maintenance scenario means extended downtime. Verifying the coil type required — from the existing installation label, the electrical drawing, or the circuit breaker manual — before placing the purchase order eliminates this risk. When in doubt, providing the circuit breaker nameplate model number to your distributor and asking them to confirm compatibility is the correct approach. LeadTime.ca technical staff can assist with this confirmation before the order ships.

Wiring and Installation Overview for the LV429407

The following points cover the key requirements for a correct LV429407 installation. For full step-by-step procedures, refer to the Schneider Electric circuit breaker installation manual for your specific Compact NSX, PowerPact, or EasyPact CVS model.

  • De-energize the circuit breaker fully before installing the coil cartridge — confirm zero voltage using a calibrated multimeter or voltage tester before handling the coil slot
  • Insert the LV429407 coil cartridge into the designated coil slot on the circuit breaker; the keyed interface prevents incorrect orientation — push until the cartridge seats fully and is retained positively
  • Connect control circuit conductors (control voltage phase and return) to the screwless spring terminals on the coil; terminals accept standard control wire gauges and do not require torque tools — insert wire and verify seating depth
  • Before restoring load power, apply control voltage to the coil terminals and measure voltage across them to confirm the supply matches the coil rating (220-240VAC or 208-277VAC as applicable)
  • Perform a commissioning test by interrupting the control voltage supply to confirm the circuit breaker opens as expected; document the test result in facility maintenance records before returning the breaker to service

Compatible Circuit Breaker Families and System Expansion Notes

The LV429407 is designed exclusively for the following Schneider Electric circuit breaker families. Do not attempt to install this coil in any other breaker family — the physical interface and internal mechanism are not compatible outside this group.

  • Compact NSX — Frame sizes 100, 160, 250, 400, and 630 A; the primary target family for this coil
  • PowerPact Multistandard — Multi-standard design confirmed compatible with LV429407 MN coil type
  • EasyPact CVS — Compatible including load switch and motor protection switch variants within this family
  • MX Shunt Release Coil — Mutually exclusive with LV429407; only one coil (MN or MX) can occupy the coil slot at one time; if MX is present, it must be removed before installing LV429407
  • MicroLogic and Micrologic trip units — The LV429407 operates as an independent auxiliary; it functions alongside electronic trip units without direct integration or configuration interaction

The LV429407 is not compatible with Schneider Electric C120, Masterpact, or TeSys product families. Different breaker families use different coil interface designs and cannot accept this cartridge.

Wrong-Part Prevention Checklist Before Ordering the LV429407

Run through every item on this checklist before submitting your purchase order. Each check corresponds to a real failure mode that results in receiving the wrong part or a failed installation:

  1. Confirm circuit breaker base model is Compact NSX, PowerPact Multistandard, or EasyPact CVS (LV429407 does NOT fit other Schneider breaker families)
  2. Verify control circuit voltage matches available rating: 220-240VAC 50/60Hz OR 208-277VAC 60Hz (single product covers both; verify which is ordered)
  3. Confirm circuit breaker frame size is NSX 100, 160, 250, 400, or 630 A (check breaker nameplate)
  4. Confirm the position slots on circuit breaker allow MN type coil (Compact NSX, PowerPact, EasyPact CVS allow either MX or MN, not both simultaneously)
  5. Verify terminal connection type needed is screwless spring (this model); some installations may require cage clamp or screw terminals (different SKU)
  6. Check that control voltage monitoring is the actual requirement (if only emergency stop is needed, local mechanical solenoid may be simpler alternative)

If any item on this checklist raises a question, contact LeadTime.ca before ordering — confirming compatibility takes minutes and prevents a costly return or installation delay.

Frequently Asked Questions

Can I install the LV429407 in the same breaker that already has an MX shunt release coil?

No. The Compact NSX, PowerPact Multistandard, and EasyPact CVS circuit breakers accept either one MN coil or one MX coil in the coil slot — never both simultaneously. If an MX coil is currently installed and you require MN-type undervoltage release functionality, the MX coil must be physically removed first. Plan for this step in your maintenance schedule and verify the MX removal procedure in the circuit breaker installation manual before beginning work.

What happens if my control circuit voltage sits between the two rated ranges — for example, at 250VAC?

250VAC falls within the 220-240VAC range at its upper tolerance and also within the 208-277VAC range, so the LV429407 covers this voltage. The critical step is measuring actual control circuit voltage at the installation point with a multimeter and confirming the measured value falls within one of the two rated bands. Do not rely on facility nominal voltage alone — confirm with a measurement before installation.

Does the LV429407 trip the breaker if the control wire is physically cut or disconnected?

Yes. The MN coil is a fail-safe undervoltage device — it holds the breaker closed only while sufficient control voltage is present above 35% of rated voltage (Un). If the control wire is cut, the coil loses its energizing voltage, drops below the threshold, and the breaker opens automatically. This fail-safe characteristic is a core reason the MN coil is specified for emergency stop and safety isolation circuits rather than an MX shunt release.

Is the LV429407 a direct replacement for a failed MN coil in an existing Compact NSX installation?

Yes, provided the voltage rating matches. The LV429407 is a plug-in cartridge designed for the Compact NSX coil slot. Before ordering the replacement, confirm the voltage rating on the failed coil label or from the original electrical drawings, and verify it matches either the 220-240VAC 50/60Hz or 208-277VAC 60Hz rating on the LV429407. If both match, it is a direct drop-in replacement with no wiring modifications required beyond reconnecting the control conductors.

Does the LV429407 require any configuration or programming after installation?

No. The LV429407 is a passive electromechanical device with a fixed trip threshold defined at below 35% of rated voltage (Un) per IEC 60947-2. There is no parameter setting, software configuration, or communication interface required. Installation is physical mounting plus control circuit wiring, followed by a commissioning test to verify the breaker opens when control voltage is removed. No programming tools or software are needed.

Will the LV429407 work with Schneider MicroLogic or Micrologic electronic trip units in the same breaker?

Yes, they operate independently. The LV429407 functions as an independent auxiliary release mechanism — it does not interfere with or replace the electronic trip unit's overcurrent, ground fault, or other protective functions. Both the LV429407 and the electronic trip unit can be installed in the same Compact NSX breaker simultaneously, each performing its own protection role. There is no direct signal integration or configuration interaction between the two.

Why Order the LV429407 From LeadTime.ca

  • Ships worldwide — suitable for facilities in North America, Europe, Asia-Pacific, and beyond with no regional sourcing restrictions
  • Technical staff available to confirm voltage rating and coil type compatibility before the order ships — preventing the most common and costly ordering mistake for this part
  • Stocks specialized Compact NSX accessories including voltage release coils for both maintenance replacement and new panel build quantities
  • Volume pricing available for bulk orders — contact for current pricing on multi-unit procurement for facility standardization projects
  • Fast response for emergency maintenance scenarios where a disabled circuit breaker creates an urgent production or safety situation

LV429407 At-a-Glance Summary

  • MN-type undervoltage release coil — trips Compact NSX breaker when control voltage drops below 35% of rated voltage (Un)
  • Rated control voltages: 220-240VAC at 50/60Hz and 208-277VAC at 60Hz — both covered by single LV429407 part number
  • Compatible circuit breaker families: Compact NSX (100, 160, 250, 400, 630 A frames), PowerPact Multistandard, EasyPact CVS only
  • Not compatible with Schneider C120, Masterpact, or TeSys families — confirm breaker nameplate before ordering
  • Terminal type: screwless spring — no torque tools required for control circuit connections
  • Certifications: IEC 60947-2 compliant, UL Listed, CSA Certified — meets North American industrial and commercial installation requirements
  • Only one coil (MN or MX) per breaker — existing MX coil must be removed before LV429407 can be installed
  • Fail-safe operation: breaker opens on loss of control voltage, not on application of a trip signal — correct type for emergency stop and load shedding circuits
  • Commissioning requires a voltage reduction test to below 35% of Un to verify correct trip operation before returning breaker to service

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