Contactors; Installation Of A Can Communication System - Zapi EPS-AC0 SWs&ENC User Manual

7.5 Contactors

According to EN1175 5.9.6, a contactor to cut the line to the eps-ac0 is not strictly
required. In fact in an AC system, the steer is automatically de-energized when a
power failure occurs. In a DC system with permanent magnet motor instead, a short
circuit in a power device, gets the steering motor rotates at maximum speed (and so
it is necessary to cut off the line from the controller).
U
A power contactor is still useful to remove the battery from controller when a
power failure occurs. This is useful in order to limit the time in which a
damaged controller remains battery connected. When a power contactor is
used, the contactor coil shall be connected to a power supply through the
eps-ac0 safety contact.

7.6 Installation of a CAN Communication System

4
CAN stands for Controller Area Network. It is a communication protocol for real time
control application. CAN operates at data rate of up to 1 Megabits per second.
It was invented by the German company Bosch to be used in the car industry to
permit communication among the various electronic modules of a vehicle,
connected as illustrated in the figure below:
The best cable for can connections is the twisted pair; if it is necessary to increase
the immunity of the system to disturbances, a good choice would be to use a cable
with a shield connected to the frame of the truck. Sometimes it is sufficient a simple
double wire cable or a duplex cable not shielded.
In a system like an industrial truck, where power cables carry hundreds of Ampere,
there are voltage drops due to the impedance of the cables, and that could cause
errors on the data transmitted through the can wires.
AEMZP0EA - EPS-AC0 SWs&ENC - User Manual Page - 29/95