Leach International Equipment and Relays

Leach International power distribution hardware for aerospace, rail transit and heavy energy infrastructure: engineered units and replacement components selected to application requirements.

Leach International: engineering heritage and global profile since 1919

Leach International Corporation has designed and manufactured power distribution equipment and switching devices since 1919. Operating under TransDigm Group, the company provides dependable hardware for aerospace, space missions, rail transit and high-demand energy infrastructure.

Founded in 1919 by break-in keying relay pioneer Val Leach in the USA
Operating unit of TransDigm Group with sites in North America and Europe
Core portfolio: hermetic relays, contactors and aviation PDU assemblies
Main manufacturing centers in Buena Park, California and Sarralbe, France

Leach electromagnetic and hermetic relays: Balanced-Force and Balanced-Armature

Military-qualified miniature, subminiature and crystal-can relays switch dry circuits and loads up to 75 amps DC and AC. Hermetically sealed enclosures shield contacts from pollutants, moisture and extreme temperatures, withstanding vibration and mechanical shock levels up to 200G.

Switching low-level signal paths and heavy loads up to 75 amps DC/AC
Hermetically sealed enclosures rated for vibration and shock up to 200G
Balanced-Force and balanced armature actuators with low contact bounce
Established series X, XL, Y, YA, YL, JA, JS, KA across multiple contact layouts

Heavy-duty DC and AC power contactors: ratings from 25 to 1000 amps

Leach power contactors switch high-current electrical circuits in demanding aerospace and rail environments. Current ratings span 25 to 1000 amps, offering latching and non-latching mechanisms, busbar-mount layouts and plug-in LRU configurations for rapid line-level replacement.

Switching heavy-duty AC, DC and high-voltage DC circuits up to 1000 A
Ratings for 28 VDC buses and 115 VAC 400 Hz three-phase aircraft networks
Line Replaceable Unit (LRU) plug-in bases and busbar-mount geometries
Field-proven series 9123, 9124, HC, HCD, HCP with auxiliary status loops

Solid State Power Controllers (SSPC): semiconductor switching and protection

Leach solid-state power controllers in the EPM and P series replace conventional circuit breakers and relays. They deliver high-speed electronic I²t fault clearing, thermal memory, zero-voltage turn-on for AC devices, arcless operation and real-time digital current monitoring.

Semiconductor channel switching from 12 to 150 A without contact degradation
True I²t inverse-time overcurrent curves with internal thermal memory
Zero-voltage turn-on and zero-current turn-off minimizing voltage transients
Dedicated controller lines EPM-109, EPM-110, EPM-111, EPM-112, P600, P800

Power Distribution Units (PDU): primary and secondary electrical assemblies

Integrated Leach PDU assemblies combine power contactors, relays, current sensors and logic controllers into compact enclosures. The assemblies incorporate multi-tier Built-in-Test (PBIT at startup, continuous CBIT and manual IBIT) to isolate electrical faults before downtime occurs.

Primary and secondary AC/DC electrical distribution assemblies for aircraft
Comprehensive Built-in-Test hierarchy: startup PBIT, running CBIT, manual IBIT
Parallel arc detection, phase imbalance isolation and short circuit protection
Integration of thrust reverser relays, windshield anti-ice and warning panels

Mounting sockets, headers and hardware: connection bases for relays

Leach manufactures specialized mounting sockets, mating receptacles and mounting hardware designed for its relay and contactor families. Termination styles include solder hooks, crimp pins, PCB thru-hole leads and track-mounting bases for convenient replacement during scheduled overhauls.

Dedicated mounting sockets matched to miniature and subminiature relay housings
Connection geometries: solder lugs, removable crimp contacts, PCB solder pins
High-grade dielectric insulation materials rated for wide thermal ranges
Positive locking mechanisms and retaining clips preventing vibration detachment

Leach electromagnetic and hermetic relays: switching design and parameters

Leach International Corporation designs and manufactures high-reliability electromagnetic relays engineered for severe airborne and ground electrical systems.

The product catalog features military-qualified miniature, subminiature and crystal-can relays capable of switching dry-circuit low-level telemetry lines as well as power demands up to 75 amps across 28 VDC and 115 VAC 400 Hz electrical networks.

Balanced-Force and balanced-armature magnetic actuators reduce moving mass and eliminate contact bounce.

Hermetically sealed metallic enclosures protect contact assemblies against atmospheric moisture, dust and oxidation across operating temperatures from -65 to +125 degrees Celsius, enduring mechanical shocks and vibration up to 200G.

Engineers select replacement devices by specifying the exact manufacturer part number (including X, XL, Y, JA and KA families) or electrical circuit parameters such as operating current, coil voltage and contact arrangement.

Heavy-duty DC and AC power contactors from Leach International

Leach power contactors provide reliable remote switching for high-amperage electrical equipment on aircraft, locomotives and heavy industrial machinery. The contactor portfolio includes latching and non-latching models spanning current ratings from 25 to 1000 amps.

Units are engineered for 28 VDC main power buses, 270 V high-voltage DC distribution, and three-phase 115/200 VAC 400 Hz aviation networks meeting stringent electromagnetic compatibility guidelines.

To accelerate maintenance turnarounds, Leach developed contactors as Line Replaceable Units (LRU) featuring quick-disconnect plug-in interfaces alongside lightweight busbar-mount geometries. Auxiliary contact loops report real-time pole positions back to digital control systems.

Unit selection is completed using contactor nameplate markings, mounting envelope dimensions and load circuit electrical ratings.

Solid State Power Controllers (SSPC): semiconductor power routing

Leach solid-state power controllers in the EPM and P series provide an advanced semiconductor alternative to electromechanical relays and thermal circuit breakers.

Operating across current ratings from 12 to 150 amps, these solid-state units eliminate mechanical moving contacts, preventing electrical arcing and physical contact wear to extend maintenance intervals in primary and secondary distribution panels.

Embedded microelectronics execute precise I²t inverse-time overcurrent trip curves while preserving thermal memory across operational cycles, safeguarding wire harnesses from thermal damage during repeated startups.

For alternating-current circuits, the controllers incorporate zero-voltage turn-on algorithms to minimize electromagnetic interference. Diagnostic status outputs continuously stream channel telemetry to supervisory digital buses.

Power Distribution Units (PDU): primary and secondary electrical integration

Integrated Leach Power Distribution Units assemble contactors, relays, current sensing devices and supervisory electronics into unified modular enclosures.

These assemblies manage primary and secondary electrical distribution for 28 VDC and 115 VAC 400 Hz buses across aircraft platforms, railway rolling stock and heavy industrial facilities.

Leach distribution assemblies feature comprehensive multi-tier Built-in-Test (BIT) architecture: automatic power-on BIT (PBIT) validates system readiness at startup, continuous BIT (CBIT) monitors operational health during run time, and initiated BIT (IBIT) enables maintenance personnel to execute focused diagnostic routines.

Modules integrate parallel arc fault protection, ground fault interrupters and windshield anti-ice controllers.

Mounting sockets, headers and connection hardware from Leach

Leach manufactures dedicated mounting sockets, mating headers and installation hardware designed to match its miniature and subminiature relay families. Termination options include solder hooks, removable crimp contacts, through-hole printed circuit board pins and track-mount bases.

Utilizing manufacturer mounting sockets streamlines unit replacement during scheduled maintenance overhauls without requiring wiring harness rework.

Socket bodies are molded from flame-retardant dielectric polymers resistant to aviation hydraulic fluids, lubricants and fuels. Positive locking mechanisms and heavy-duty spring clips prevent unit disconnection under intense airframe vibration.

Socket selection is determined by relay pole count, pin spacing and conductor wire gauge.

Component selection, technical verification and international delivery

We provide engineering selection, technical verification and direct supply of Leach International relays, power contactors, solid-state controllers and replacement parts.

Component cross-referencing is performed using manufacturer part numbers, military specifications (such as MIL-PRF-83536 and MIL-PRF-6106) or electrical parameters recorded on unit documentation.

All orders are processed through formal contracts with full commercial documentation and export compliance. Prior to dispatch, components undergo incoming inspection to verify part numbers, lot codes and packaging integrity.

Shipments are transported by international carriers to designated terminals or customer manufacturing facilities globally.

Leach International and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of Leach International and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.