RZT-S Zero
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In this system the VCM is the central computer that controls everything on the mower and acts as the user inter-
face for most of the system. The VCM receives constant power from the battery pack, by a lead from the contactor
assembly on the control panel. A constant 48 volts passes through the VCM going to the key switch. If the key switch
is in the “ON” position, the 48 volts will return to the pin 9 of the VCM’s 16 pin connector VCM. When the VCM
senses the voltage at pin 9, it will turn on and display the starting procedure.
Once the operator completes the starting procedure (charger disconnected, PTO off, foot off of the drive pedals,
brake depressed, press the start button), The VCM will send 48 volts through a white wire to all of the controllers on
the control panel to turn them on. The VCM will also start monitoring all of the switches and sensor on the mower.
Most of the inputs to the VCM are doubled up for safety reasons. If the VCM senses a discrepancy in any of the
sensor inputs, the VCM will show a fault code and will either shut down the mower or limit its functionality, depending
which sensor is causing the fault.
The components of the RZT-S Zero’s electrical system
and their function:
•
Vehicle Control Module (VCM): The VCM is the
brains of the system. It receives various inputs
from the tractor, performs the necessary calcu-
lations and sends signals to the individual con-
trollers on the control panel. See Figure 5.2.
•
Control panel: The control panel consists of:
• A contactor assembly. The contactor is a
large constant duty relay similar in appear-
ance to a starter solenoid. The contactor is
enclosed in a housing with five fuses. The
contactor assembly is serviced as an entire
assembly.
• Four controllers. The VCM sends a signal to
each controller, telling them how fast and in
what direction each motor is supposed to
spin. The controllers then control the power
going to the motors, to make them spin as
directed by the VCM.
• A master ground bus. This is just a stud, insu-
lated from the panel, that is used as a com-
mon connection point for the negative wires
from the controllers and the battery pack.
See Figure 5.3.
IMPORTANT:
The controllers are connected to the
VCM in a daisy chain computer net-
work. If communication is lost with
one of the controllers, a communica-
tion fault will appear.
NOTE:
The 16 pin connector on each controller is the network connection. The white wire is power to turn the
controller on. The yellow and gray wires are the actual communication lines. Each 16 pin controller
connector has one or two jumpers in it. These jumpers set the network address for each controller. The
network address tells the controller which motor it will be controlling.
Figure 5.2
VCM
Figure 5.3
Control panel
Summary of Contents for RZT-S Zero
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