Remy International Inc., manufacturer and distributor of Delco Remy heavy-duty starters and alternators, has released the Delco Remy 55SI alternator, rated at 420 amps at 12 volts and up to 275 amps at 24 volts.

The 12-volt, 420 amp 55SI model is commonly used on fire and rescue trucks due to its compact design and high output performance at idle. The 55SI also is used on utility and work trucks to power inverters and plug-in tools, lights and other electrical equipment where it can replace a dual alternator system. The new model also supports the electrical load requirements of long haul trucks equipped with multiple battery auxiliary power units (APUs), the maker said.

24-volt 55SI alternator models rated at 250 and 275 amps are designed to meet the high electrical load demand of transit buses, mining equipment and other off-highway vehicles. The 55SI high output alternator currently is standard equipment on wheel loader and grader applications with one off-highway vehicle OEM, according to Remy International.

High efficiency alternators translate to less engine horsepower requirements, resulting in substantial fuel savings, noted Eric Bippus, senior vice president of Aftermarket Sales and Marketing. “The 55SI is the highest output Delco Remy alternator, not to mention the highest output unit in its class,” he said.