Measures Required For Specific Signals; Additional Measures - Sevcon Gen4 Applications Reference Manual

Measures required for specific signals

Battery power cables
Cables should be as short as possible. Minimise the loop area of the B+ and B- wiring. A
common mode ferrite choke may be required.
Motor power cables
Cables should be as short as possible. Minimise the loop area of the M1 M2 M3 wiring. A
common mode ferrite choke may be required
Motor encoder connection
The encoder cable must be as short as possible. A multi-core screened cable should be used.
The inner cores should be used for the encoder supply and encoder ground and the AB or UVW
signals. The cable screen should be connected to the B- terminal. Ensure that the screen does
not connect the motor chassis back to the B- terminal to avoid motor power cable current
returning through the encoder cable screen.
CAN bus
A multi-core screened cable should be used. The inner cores must be twisted pairs. One twisted
pair should be used for CANH and CANL. The other twisted pair should be used for CAN supply.
Ensure that there is a common ground connection for all nodes on the CAN bus. If there is a
node on the bus which is galvanically isolated from the Gen4 controller then the CAN ground on
this node must be connected to the Gen4 controller B-. The cable screen should be connected to
the B- terminal at the Gen4 controller
Keyswitch
The keywire should be as short as possible. Minimise the loop area of the loop formed by the
traction battery, keyswitch, keyswitch supply on the Gen4, and the B- return wire to the battery.
Do not connect additional battery loads to the keyswitch wire.
Contactor drivers
Minimise the loop area formed by the contactor driver output and the contactor supply +. Use of
twisted pair will reduce emissions. Use of screened cable with the screen connected to B- will
further reduce emissions.
Throttle input
The throttle input is referenced to the controller B- connection, it is therefore very important that
the throttle ground connection goes directly to the B- terminal on the controller. Ensure that there
is no common ground path for the throttle with the battery power connection or any other power
or switching loads on the vehicle. Screened cable for the throttle supply and wiper may be
required for higher levels of immunity, the screen should be connected to B-.

Additional measures

Where it has not been possible to meet the required EMC specifications using the standard
measures listed above it may be necessary to use one or more of the following measures:-

Use of screened cable for all control connections

Use of a Faraday cage around the controller and motor
Doc. # 177/52701
Rev. 3.3
Installation
3-7