Explanation of Function
Explanation of Function
The Mini-Hybrid system (see Figure 1) consists of
variable-speed electric fans and an EMP TMC
system controller. The Mini-Hybrid system replaces
the OEM mechanical fan and shroud, while
mounting directly to the OEM radiator with no need
to replace the radiator or charge air cooler.
Powering the Mini-Hybrid system
The Mini-Hybrid system configuration varies by
vehicle make, model, and year.
•
Each FIL15 fan can draw up to 70 Amps.
•
Each FIL11 fan can draw up to 30 Amps.
•
The OEM alternator must be replaced with a
high-output alternator. EMP will provide
recommendations.
•
Wire and alternator sizing must be suitable
for a maximum power draw scenario.
However, Mini-Hybrid systems rarely draw
maximum power in day-to-day operations.
Controlling the Mini-Hybrid system
Fan speeds are controlled automatically by the
EMP TMC system controller using three inputs:
1.
Engine coolant temperature controls fan
speeds based on temperature reported by the
ECU over J1939 CAN.
2.
Intake manifold temperature controls fan
speeds based on temperature reported by the
ECU over J1939 CAN.
3.
The air conditioning high-pressure fan switch
controls fan speeds based on AC system
pressure measured via hardwire to the
pressure switch.
Fans can be manually reversed to backflush dust
and debris from the cooling system. Fan reversal is
controlled via a momentary pushbutton located
inside the cab. Push and release the button to
activate a fan reversal.
Power consumed by the Mini-Hybrid system is
minimized by running fans only as fast as
necessary to maintain inputs at optimal values.
Power consumption is also reduced through
individual control of fans. For example, if two fans
have coverage of the AC condenser, only those two
fans will run when AC system pressure requires air
flow. In daily operations on refuse vehicles, Mini-
Hybrid systems consume less than 0.5 hp on
average.
Figure 1 - Mini-Hybrid System for 2013 Peterbilt 320
© 2016 EMP, Inc.
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