SR2912 24V Forklift Starter Relay for Heavy-Duty & Large Capacity Forklifts

The SR2912 is a heavy-duty 24V DC electromagnetic starter relay engineered for 5-25 ton large-capacity internal combustion forklifts, container handlers, reach stackers, and heavy industrial equipment operating on 24-volt electrical systems. Unlike the more common 12V relays found on 1-5 ton forklifts, the SR2912 is purpose-built for the higher current demands and more demanding duty cycles of large-capacity material handling equipment where 24V electrical architecture is standard — providing half the current draw for the same power output compared to 12V systems, which reduces cable gauge requirements and minimizes voltage drop across long cable runs typical in large-frame forklifts and port equipment. The relay switches the 150-300 ampere surge current from the dual-battery 24V system to the heavy-duty starter motor solenoid, enabling reliable cold starts of 6-12 liter displacement diesel engines even in sub-zero temperatures where battery capacity is significantly reduced.

The relay is constructed around a robust electromagnetic coil wound with heavy-gauge enameled copper wire rated for 24V DC continuous duty, generating sufficient magnetic force to positively close the silver-alloy main contacts against spring pressure. The contact surfaces are manufactured from silver-cadmium oxide composite material specifically formulated for high-voltage DC arc suppression — the 24V arc at contact break is significantly more energetic and persistent than a 12V arc, requiring enhanced contact material composition and contact gap geometry to prevent arc restrike and ensure clean interruption. The relay housing is a rugged metal or high-temperature thermoplastic enclosure with weather-resistant sealing that protects internal components from moisture, salt spray (critical for port and marine terminal applications), diesel exhaust particulate, and the extreme vibration of large-displacement diesel engines. The main current terminals are heavy-gauge M10 or M12 copper studs with stainless steel nuts and lock washers, capable of handling continuous currents of 100-150A with surge capacity to 300A. A dedicated ground stud ensures reliable coil return path even on equipment with painted or corroded chassis mounting points.

Direct OEM replacement for Konecranes, Kalmar, Hyster, Yale, Linde, Toyota, Komatsu, HELI, Hangcha, and other 5-25 ton large-capacity forklifts, reach stackers, empty container handlers, and terminal tractors using 24V electrical systems with SR2912-type starter relays. Also compatible with 24V heavy equipment including excavators, bulldozers, wheel loaders, mobile cranes, and large industrial generator sets using 24V starter circuits. Before replacement, always verify the 24V electrical system is in good condition: battery voltage should be 24.8-25.4V at rest (two 12V batteries in series), and should not drop below 19.2V during cranking. Clean all cable terminals and inspect the battery disconnect switch for high resistance — both can produce identical symptoms to a failed relay. For compatible 24V starter motors, alternators, battery isolators, and complete heavy equipment electrical system components, visit our Forklift Engine Parts section. For 24V electrical system specifications and wiring diagrams, refer to Kalmar heavy equipment documentation.

Technical Specifications

• PN: SR2912
• Type: 24V DC Heavy-Duty Electromagnetic Starter Relay
• Contact Rating: 150-300A Surge, 100-150A Continuous
• Contact Material: AgCdO Silver-Cadmium Oxide, 24V Arc-Rated
• Coil: 24V DC Heavy-Gauge Copper, Continuous Duty
• Terminals: M10/M12 Copper Studs with Stainless Hardware
• Housing: Metal / High-Temp Thermoplastic, Weather-Sealed
• Application: 5-25 Ton Large Capacity Forklifts & Heavy Equipment

Compatible Forklift & Heavy Equipment Brands

Each SR2912 relay undergoes QC: coil resistance at 20°C, contact closure at 18V minimum, contact resistance <5 milliohms, dielectric test at 1000V AC, and 100-cycle endurance test at rated current. Ships in anti-static packaging. 12-month warranty. Safety note: 24V systems carry higher available short-circuit current than 12V — always disconnect battery negative before servicing and use insulated tools. Contact our team for heavy equipment electrical support.