Delco Remy 55SI™ High Output Heavy Duty Brushless Alternator

55SI Brushless Alternator
From 12 volt applications such as utility & work trucks, fire trucks, and long haul trucks with auxiliary power units to 24 volt applications like wheel loaders, graders and mining equipment, the Delco Remy 55SI is designed to take on the demanding electrical loads of today's heavy duty vehicles. The 55SI produces up to 430 amps at 12 volts and up to 275 amps at 24 volts.  

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Performance Output 12 Volts 430 Amps
24 Volts 250 & 275 Amps
Maximum Speed 8,000 RPM Continuous
9,000 RPM Intermittent
Rotation Clockwise
Temperature Rating 12V 430A 93°C / 200°F
24V 250A 125°C / 257°F
24V 275A 110°C / 230°F
Mounting Pad
Polarity Negative Ground
Efficiency 12 Volts 73%
24 Volts 80%
Weight 43.2 lbs / 19.6 kg
Stator Diameter 6.89 in / 175 mm
Length 11.25 in / 285.9 mm
Remote Sense Standard
*(US /Canada Only)
3 year / unlimited miles


55SI Dimensions

Remote Sense

Remote Sense can reduce battery charge time by 50%. Some 35SI models are equipped with Remote Sense which utilizes a second wire that reads the actual to boost its output to compensate for the voltage drop, ensuring 14 Volts at the battery. The proper voltage forces more current into the battery bringing it to a full state of charge between vehicle stops.

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