User Manual

Connecting Power and Motors to the Controller
30 Advanced Digital Motor Controller User Manual V2.0, July 8, 2019
Controllers with sensors on the motor terminals provide accurate motor current sensing in
all conditions, and provide a good estimate battery current value. Some controller models
have sensors on the motor and on the battery terminals, and provide the most accurate
current sensing as all are actually measured values.
Whether sensors are on the motor or/and battery terminals can be found in the product’s
datasheet
Important Warning
Do not connect a motor that is rated at a higher current than the controller.
Power Regeneration Considerations
When a motor is spinning faster than it would normally at the applied voltage, such as
when moving downhill or decelerating, the motor acts as a generator. In such cases, the
current will flow in the opposite direction, back to the power source.
It is therefore essential that the controller is connected to rechargeable batteries. If a pow-
er supply is used instead, the current will attempt to flow back in the power supply during
regeneration, potentially damaging it and/or the controller.
Regeneration can also cause potential problems if the battery is disconnected while
the motors are still spinning. In such a case, the energy generated by the motor will
keep the controller On, and depending on the command level applied at that time, the
regenerated current will attempt to flow back to the battery. Since none is present, the
voltage will rise to potentially unsafe levels. The controller includes an overvoltage pro-
tection circuit to prevent damage to the output transistors (see “Using the Controller
with a Power Supply” below). However, if there is a possibility that the motor could be
made to spin and generate a voltage higher than 40V, a path to the battery must be pro-
vided, even after a fuse is blown. This can be accomplished by inserting a diode across
the fuse as shown in Figure 1-2 on page 24.
Please download the Application Note “Understanding Regeneration” from the www.ro-
boteq.com for an in-depth discussion of this complex but important topic.
Important Warning
Use the controller only with a rechargeable battery as supply to the Motor Power
wires (thick black and red wires). If a transformer or power supply is used, damage
to the controller and/or power supply may occur during regeneration. See “Using
the Controller with a Power Supply” below for details.
Important Warning
Avoid switching Off or cutting open the main power cables while the motors are
spinning. Damage to the controller may occur. Always ground the Power Control
wire to turn the controller Off.