ANL325 - Limiter 32VAC-80VDC 325A

ANL325 – Limiter 32VAC-80VDC 325A

Available now on the Airparts.aero Marketplace.

Overview

The ANL325 is a high-amperage, non-time-delay current limiter, engineered to provide catastrophic overcurrent protection in high-energy DC electrical systems, including those found in modern aircraft. Manufactured by industry leaders like Eaton Bussmann, this 325-amp limiter acts as a high-capacity fuse, designed to isolate major faults and protect main battery busses, alternator outputs, and other heavy-gauge wiring from the destructive effects of a massive short circuit. Its robust, bolt-down design ensures a secure connection in high-vibration environments, making it a critical safety component for primary power distribution.

Key Features

• High Interrupt Capacity: Engineered with a very high interrupt rating—2,700 Amps at 80 VDC and 6,000 Amps at 32 VAC. This means it can safely open a circuit experiencing a catastrophic short circuit without exploding or creating a hazardous arc flash.
  
• Fast-Acting Protection: As a non-time-delay limiter, it is designed to open almost instantaneously when subjected to a major fault current, providing rapid protection for downstream wiring and components.
• Visible Element Window: Features a clear mica or glass window that allows for immediate visual inspection. A broken or melted internal link provides a clear indication that the limiter has opened the circuit due to a fault.
  
• Bolt-Down Design: The blade-style terminals are designed to be securely bolted to a fuse block or bus bar. This ensures a low-resistance connection and prevents the limiter from coming loose under severe vibration.
  
• Silver-Plated Copper Link: The internal fusible link is made from silver-plated copper, which provides excellent electrical conductivity and stable, predictable fusing characteristics.
  

Technical Specifications

• Part Number: ANL325
• Component Type: Current Limiter / Limiter Fuse
• Current Rating: 325 Amps
• Voltage Rating: 32 VAC / 80 VDC
  
• Interrupt Rating:
  • 2,700 Amps @ 80 VDC
  • 6,000 Amps @ 32 VAC
    
• Body Material: Melamine / Glass-Melamine Composite
  
• Link Material: Silver-Plated Copper
• Mounting Style: Bolt-Down / Stud Mount
• Agency Approvals: UL Recognized, CSA Certified, SAE J1171 Compliant
  

Aircraft Compatibility

The ANL325 is a universal electrical system component used in various aircraft where high-amperage circuit protection is required. Its use is specified by the aircraft manufacturer based on the electrical system's architecture and fault current analysis.

• Common System Applications:
  • Main Battery Bus Protection: Installed in-line with the main battery cable to protect the entire electrical system from a battery short circuit.
  • Alternator/Generator Output Protection: Used on the main output line of high-amperage alternators or starter-generators.
  • Ground Power Unit (GPU) Circuit: Protects the aircraft's ground power receptacle and associated wiring.
  • High-Load Sub-Busses: Can be used to protect entire sub-panels that feed high-draw equipment like air conditioning or de-ice systems.

Applicable Textron Aircraft

• Premier Model 390

List not comprehensive, may be applicable on other models.

Applications

The ANL325 is a critical safety device for managing high-energy electrical systems:

• Catastrophic Fault Isolation: Its primary function is to act as a "last line of defense," isolating a catastrophic short circuit to prevent a major electrical fire or the complete destruction of the main electrical bus.
• Protecting Heavy-Gauge Wiring: Safeguards the large, heavy, and expensive main power cables from melting during a fault condition.

Why Choose ANL325?

While circuit breakers protect individual circuits, a current limiter like the ANL325 protects the entire electrical backbone of the aircraft. Its extremely high interrupt rating is a critical safety feature that standard circuit breakers cannot provide. In the event of a dead short on a main power bus, the ANL325 is designed to absorb the immense energy and safely open the circuit. Using a high-quality, certified limiter from a manufacturer like Eaton Bussmann is a non-negotiable requirement for ensuring the safety and integrity of any high-amperage aircraft electrical system.

Order Your ANL325 Limiters Now

Provide the ultimate protection for your aircraft's high-power electrical system with a certified, high-interrupt capacity current limiter. Visit Airparts.aero to order your ANL325 limiters today.

A current limiter like the ANL325 is fundamentally different from a resettable circuit breaker in its role. A thermal or magnetic circuit breaker is designed to protect a specific appliance and its associated wiring from functional overloads. A current limiter, however, is designed to protect the source of power and the main distribution wiring from a fault of massive proportions. Its interrupt rating of 2,700 amps signifies its ability to handle the enormous available fault current from a large aircraft battery. When a short circuit occurs, the silver-plated copper link vaporizes in a fraction of a second, creating an arc within the silica-filled melamine body. The silica sand melts and quenches the arc, safely interrupting the flow of current without allowing a sustained, destructive electrical arc.

Note: This is a flight-critical electrical safety device. It must only be replaced with a limiter of the exact same amperage rating. Installation must be performed by a certified A&P mechanic or avionics technician. Ensure all power is disconnected before replacement. Bolt-down terminals must be torqued to the specified value to ensure a low-resistance connection.