442-3418 (4423418) is a 24V 5-pin electromagnetic relay designed specifically for Caterpillar equipment. Classified as a general-purpose control relay, it is widely utilized in heavy machinery—such as excavators and loaders—to manage high-power circuits for functions including engine starting, cooling fans, lighting, and hydraulic pumps, thereby enabling low-current signals to drive high-current loads. I. Core Parameters and Specifications

Model: 442-3418 / 4423418

Type: Electromagnetic Control Relay (5-Pin / 5-Terminal)

Rated Voltage: 24V DC (Standard voltage for heavy machinery)

Contact Configuration: 1 Normally Open (NO) + 1 Normally Closed (NC) + Common Terminal (COM) (Changeover Type)

Protection Rating: IP67 (Dustproof, waterproof, and vibration-resistant; suitable for harsh construction site environments)

Material: Polyurethane housing + Copper alloy contacts; resistant to high temperatures and corrosion

Operating Temperature: -40°C to +125°C

Contact Capacity: 30A/24V (Suitable for high-current devices such as starter motors, cooling fans, etc.)

II. Compatible Models (Mainstream)

Excavators: 320D2, 323D2, 326D2, 330D2, 336D2, 320GC, 336GC, etc.

Loaders / Dozers: 950GC, 962K, D6N, D6T, etc.

Engines: C4.4, C6.6, C7.1, C9 Series

Others: Motor graders, road rollers, generator sets, and all other 24V Caterpillar equipment series

IV. Alternative Models and Procurement

1. OEM / Equivalent Specification Alternatives

Caterpillar OEM: 442-3418 (Original Part)

Equivalent Specification Alternatives: 161-3128, 3E-6477, 111-4871 (All are general-purpose 24V 5-pin Caterpillar relays and are directly interchangeable)

General Industrial Alternatives: 24V 5-pin 30A Electromagnetic Relay (Requires verification of pin configuration and mounting dimensions)

V. Selection and Installation Guidelines

Voltage Matching: Must be 24V DC; strictly prohibited for use in 12V systems

Pin Verification: Strictly adhere to... Wiring (Terminals 85/86/30/87/87a): Ensure correct connections to prevent coil or contact burnout caused by miswiring.

Load Matching: Verify that the contact current rating is greater than or equal to the device's operating current (e.g., ≥ 30A for a starter motor).

Installation & Protection: Keep away from high-temperature and oil-contaminated areas; ensure proper waterproofing, sealing, and secure mounting.