Honeywell 3888058-7 Ignition Exciter

Honeywell 3888058-7 High-Voltage Turbine Ignition Exciter

The Honeywell 3888058-7 Ignition Exciter (co-manufactured/supported by Champion Aerospace) is a high-energy, capacitor-discharge ignition unit engineered specifically for aerospace auxiliary power units (APUs) and industrial gas turbine installations. As a vital line-replaceable unit (LRU) under ATA Chapter 49, this exciter converts low-voltage aircraft or marine electrical bus power into high-voltage, high-frequency intermittent pulses capable of firing stubborn fuel-air mixtures under extreme thermal, vibrational, and altitude/pressure variances.

From a marine and industrial gas turbine operations perspective, maintaining reliable ignition sequencing during cold cranking or emergency restart phases is non-negotiable. This unit delivers precision thermal and electrical tolerance, minimizing spark plug erosion while securing instantaneous flame propagation.

Model Details

• Manufacturer: Honeywell Aerospace / Champion Aerospace
• Manufacturer Part Number (MPN): 3888058-7
• Superceded Part Numbers: 3888058-5
• Primary Application: Gas Turbine Auxiliary Power Units (APUs)
• Design Configuration: Single Input / Single Output (SISO) solid-state storage discharge architecture

Compatible Equipment Models

• Honeywell APU Series: 331-600, 131-9A, 131-9B
• Airframe/Engine Integration: Utilized across various commercial transport category aircraft and heavy industrial gas turbine generator setups.

Part Number Cross-References

• Boeing / OEM ID: 3888058-5 (Legacy version, directly upgraded to -7)
• Alternative Catalog Codes: HMR-3888058-7

Key Features

1. Hermetically Sealed Housing: Completely potted internal circuitry prevents short-circuiting caused by high humidity, salt-mist environments, or hydraulic fluid contamination.
2. Optimized Spark Energy: Delivers high-voltage peak discharge to guarantee rapid light-off while preventing premature degradation of igniter plugs.
3. Direct Interchangeability: Drops straight into legacy 3888058-5 footprints without requiring structural harness or mounting bracket modifications.
4. Solid-State Reliability: Eliminates moving parts, rendering the unit exceptionally resistant to high-frequency compressor vibration.
5. Advanced Thermal Management: Internal heat dissipation architecture supports extended crank cycles during cold-weather operations.

Primary Industrial Applications

• Commercial and regional aircraft auxiliary power unit (APU) starting circuits
• Marine gas turbine auxiliary generator ignition systems
• Ground power units (GPUs) utilizing Honeywell turbine cores
• Industrial stationary gas turbine peaking units

Engineer Expert’s Guide

Marine/Aerospace Maintenance Tip: When replacing the 3888058-7 exciter, always inspect the high-tension output coaxial lead for microscopic dielectric breakdown or carbon tracking. A degraded ignition lead will short the high-voltage pulse before it reaches the spark igniter, even if a brand-new exciter is installed. Apply a thin layer of approved high-temperature compound to thread interfaces to avoid galvanic corrosion in marine-adjacent installations. Always ground the unit thoroughly before performing continuity checks to protect sensitive internal storage capacitors from static discharge damage.

Frequently Asked Questions

What is the difference between part number 3888058-5 and 3888058-7?

Part number 3888058-7 is the direct backward-compatible OEM upgrade superseding the older -5 variant. It features enhanced internal component stability against thermal soaking and vibration fatigue.

Can this ignition exciter be repaired in the field?

No. Due to the high-voltage internal potting and vacuum sealing required to prevent arcing at high altitudes or damp conditions, these units are non-field-repairable sealed LRUs. Faulty units must be swapped and sent to an authorized overhaul facility.