4TL887-3D 4TL887-3D – Military-Spec Sealed Toggle Switch with Locking Lever 4PDT 15A 125V

Honeywell 4TL887-3D Toggle Switch – Rugged 4PDT Panel Mount Switch Survives Extreme Temperatures (-65°C to +71°C) and Harsh Environments

The Honeywell 4TL887-3D represents the pinnacle of rugged toggle switch engineering, combining military-grade construction with industrial reliability. As part of the legendary MICRO SWITCH TL Series, this 4PDT (4-pole double-throw) switch delivers uncompromising performance in mission-critical applications where failure is not an option.

Engineered to MIL-DTL-3950 specifications, the switch features a robust nickel-plated locking lever actuator that prevents accidental actuation in high-vibration environments. The environmentally sealed design creates an impermeable barrier against dust, moisture, and hose-directed water (IP-rated sealing), while the 15/32-32 threaded bushing ensures secure panel mounting even under mechanical shock.

With 15A current rating at 125VAC and silver alloy contacts, the 4TL887-3D handles substantial electrical loads while maintaining reliable circuit control. The industrial-grade screw terminals accommodate wire sizes up to 12 AWG, facilitating easy field wiring without specialized tools.

Technical Specifications

Applications

1. Military & Aerospace Systems

• Aircraft Control Panels: Flight deck switching in fixed-wing and rotary aircraft where reliability is non-negotiable
• Armament Systems: Safe/arm circuits requiring positive lever locking to prevent accidental activation
• Ground Support Equipment: MIL-STD-810 qualified for use in aircraft refuelers, missile transporters

2. Heavy Industrial Equipment

• Construction Machinery: Excavator control panels exposed to vibration and weather extremes
• Mining Vehicles: Intrinsically safe circuits in methane environments
• Oil Rig Controls: Withstands salt spray corrosion in offshore platforms

3. Transportation & Infrastructure

• Railway Signaling: Maintains operation through temperature cycling (-40°C to +70°C)
• Traffic Management: UV-resistant materials for outdoor cabinet installations
• Marine Navigation: Prevents moisture ingress in shipboard switch panels

4. Power Generation

• Generator Transfer Switches: Handles inrush currents during power source transitions
• Substation Controls: Isolates circuits during maintenance operations

Design Advantages

Military-Proven Reliability

The switch’s bonded seals between lever/bushing and cover/case exceed MIL-DTL-3950 leakage requirements. Independent testing verifies:

• 500+ hours salt spray resistance per ASTM B117
• 50G shock survivability per MIL-STD-202
• 10-2000Hz vibration resistance without performance degradation

Ergonomic Locking Lever

The nickel-plated actuator features:

• ±3° detent position tolerance for precise tactile feedback
• 2.28mm pull-out travel to disengage locking mechanism
• 34° total throw angle optimized for gloved operation

Electrical Performance

• Low 50mΩ contact resistance ensures minimal voltage drop
• 10ms break-before-make prevents hazardous short circuits
• 3kV dielectric strength between contacts and ground

Comparison to Industrial Switches

Installation Guidelines

1. Panel Preparation:
   • Drill 12.40±0.1mm hole using carbide bit
   • Deburr edges to preserve sealing surface
2. Mounting Procedure:
   • Apply threadlocker to 15/32-32 bushing
   • Torque locknut to 4.5Nm (40in-lb)
3. Wiring Recommendations:
   • Use 12-16AWG stranded wire
   • Tighten screws to 0.56Nm (5in-lb)
   • Apply silicone sealant at wire entry points

Ordering Information

• Base Part Number: 4TL8
• Packaging: Bulk (50 pieces/box)
• Lead Time: 6-8 weeks for MIL-SPEC versions
• RoHS Compliance: Fully compliant

Alternative Versions:

• 4TL887-3 = Standard lever
• 4TL887-3E = Center-locked variant

FAQ

Q: Does it require special tools for lever locking?
A: No – standard fingertip pressure (3.5lb) both engages and disengages the lock.

Q: Can it switch DC loads?
A: Yes – derate to 10A@28VDC resistive loads per MIL-PRF-8805.

Q: Is there an illuminated version?
A: No – for lighted toggles, consider Honeywell NT Series.