Jaguar Amperage Flow

[Al Skierkiewicz]

Originally Posted by Verrazano

1) Wire the connection between the Jaguar and motor with a resetting breaker.

Verrazano,
I am a little confused by this part of the question. Breakers are required. The unfortunate thing about them is that they are meant largely, to protect the wiring and prevent fires. They do very little to protect the motors or the controllers.
As to the chain to wheels, there are other components to this arrangement that provide from some reduction ratio between motor and final drive. However, teams that chose this approach must use additional bearings as the bearing assembly in the CIM motor is not designed for the kind of side loading normally encountered in this type of chain drive. It is possible that a correct reduction was designed into your robot such that normal motor operation was expected. The side loading presents very high friction loads to the motor, resulting in significantly increased current. If you had coupled this to a normal tank drive with high friction wheels, then you likely were putting the motor at or near rated stall current of 133 amps. The Jaguar cannot handle this current for long. The newer Jaguar design has current capability of 90-100 amps and repeated demands above this point result in failure of the device. The Jaguar does have internal protections for this and will try to enter a current protection mode before damage can occur. However, repeated high current demands can destroy the Jaguar or Victor for that matter.

As Ether has hinted, measuring the voltage drop across the power wiring feeding the Jaguar will give you an idea of the current each device is delivering. Using #10 wire, 100 amps will drop 0.1 volt per foot. While this requires some special circuitry, it is possible to do so with the analog inputs to the Crio. Remember that the current flowing to the Jaguar on the positive lead is also flowing away from the Jaguar on the negative lead. Low impedance current monitoring is legal under the 2011 rules and will likely also be legal in 2012 as a custom circuit (see 2011 R43).