TYPICAL EV WIRING is shown below. Our large EVMTC controller is used with an external
power drop contactor. This contactor is driven by the Key-switch and a micro-switch on the Potbox. The
Contactor has a precharge resistor to power the controller capacitors before high-current is connected.
The 12V Accessory Battery is used to power the Key-switch. This is possible due to Controller Isolated
Also, our Cross Charger is used to keep 12V accessory battery charged. Note the accessory battery
negative is connected to vehicle chassis but the traction battery negative is not.
ElectroCraft EV Systems
EV Circuit Diagrams
SMALL EV (SCOOTER) WIRING:
Diagram below shows a scooter wiring using our EVMTC24V-55A controller. This controller uses
a Hall-effect type throttle. A 5K-pot type controller has similar wiring diagram.
SMALL MOTOR DIRECTION CONTROL:
A single DPDT relay can be used to reverse the direction of a
small permanent magnet motor. The contact rating of the relay
should be around maximum motor current.
For Large Motors, usually, 2 high-current SPST relays
(Contactors) are used. The Circuits are shown next, in this
SEPEX MOTOR REVERSAL:
A DPDT relay could also be used in SEPEX motor
reversal. This is because SEPEX motor has low
field current and DPDT relays normally can meet
the contact rating requirement.
Here, the controller drives the relay ON or OFF.
As a result, the relay contacts change the battery
voltage polarity applied to the motor field winding.
SERIES AND PERMANENT-MAGNET MOTOR REVERSAL:
Single DPDT relays have low contact ratings. For large motors, two Large SPDT Contactor relays are used. The
circuits are given below for Series and Permanent Magnet type large motors (they do need high current reversal).
For Series motor, the polarity of the field is changed with respect to the armature. For PM motor, the overall
current is reversed. Our EVMTC controller can be customized to output drive signals for two (R1 and R2)
relays. This is commanded either by a toggle switch input to the controller or a center-stop pot.
LARGE MOTOR DIRECTION CONTROL: