ARCO Zeus A275L Vortec Alternator with Terminal Block

Description

The ARCO Zeus A275L Vortec Alternator with Terminal Block is a high-output externally regulated charging solution for GM pad-mount marine engines and other demanding 12V systems. It is engineered for marine, RV, military, and commercial applications that need rapid charging of large battery banks and substantial electrical production at both cruising and idle speeds.

Heat management allows the A275L to sustain its output under heavy load. Heat-shedding E-Coat or Cerakote finishes, an externally mounted rectifier, dual cooling fans, and OEM components help the unit operate 8-20% cooler than incumbent alternators. By keeping internal temperatures down, the alternator can maintain higher amperage for longer periods and potentially reduce the amount of generator runtime needed aboard a vessel.

This large-frame model uses a 138mm stator, 16-pole P-type field, and external-only regulation. A terminal block and P-type harness are included, and the alternator requires an external regulator such as the ARCO Zeus Bluetooth Alternator Regulator. The externally regulated architecture is particularly useful for lithium charging and systems requiring programmable charging behavior. Default output voltage is 14.1V.

ARCO publishes up to 311A cold output at 9,000 alternator RPM, 227A sustained hot output at 6,000 RPM, and 198A sustained hot output at 3,000 RPM. Cut-in speed is 1,061 RPM, maximum alternator speed is 19,000 RPM, and maximum continuous operating temperature is 110°C.

The alternator uses an M8 side-mount battery post, 49K6 six-groove 49mm pulley, 17mm shaft threaded M17 x 1.5, included pulley nut and washer, and six positive plus six negative 50A avalanche-rated diodes.

The Vortec/GM pad-mount pattern replaces Mando-type alternators used on many MerCruiser and Volvo Penta GM-block engines, including listed 3.0GLM, 3.0GLP, 4.3GXi, 5.7GiL, and 5.7GXiL applications. It is SAE J1171 certified and made in the USA. See what else we carry in marine alternators.