Delco Remy Alternator Designed with Power for Commercial Transit Vehicles

Today’s mega and charter buses and other commercial transit applications are outfitted with lots of door operation, lighting, AC and other electrical-based amenities. While these ensure a comfortable user experience, they also put a demand on the system and require an alternator that’s up to the job. 

The 55SI High Output Heavy Duty Brushless Alternator from Delco Remy, a business unit of BorgWarner, has been used on specialty vehicles such as oil rigs, utility trucks, vocational vehicles for years and proven that it can withstand dust, dirt, clay and other debris. Originally geared toward off-road applications, the air-cooled 55SI has recently been improved to better survive the difficult, corrosive environment encountered in transit applications where durability and high output are essential. 

“While no physical magnets are utilized in it, the alternator does rely heavily upon mechanical physics and electromagnetic principles to generate the necessary power for the vehicle electrical system,” according to Rob Steele technical product lead for alternator engineering at BorgWarner in Noblesville, IN. 

“Our commercial vehicle alternators are based upon the Lundell machine design consisting of a field coil controlled by the integrated regulator that generates the magnetic field that is induced into the stator when rotating.  The generated AC voltage is converted to a usable DC voltage by the rectifier bridge.”   

“Traditionally, transit applications have used alternators that are so heavy they require a mechanical lift to install. Plus, they take up a lot of space and are limited on where they can be installed,” explains Steele. “The 55SI, which I like to refer to as the big brother to our popular 40SI, is smaller and more lightweight than what’s traditionally been used in this power range. This allows it to be installed by one person. Additionally, it can be used in a single or dual alternator application.” As a brushless heavy-duty alternator, it is one of the highest output air-cooled machines on the market with 33% more output than any other alternator in its class, noted Steele. 

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