Motor protection system

A vehicle comprising:

• an alternator;
• at least one traction motor configured to move at least a portion of the vehicle;
• one or more blower motors configured to cool one or more of the at least one traction motor and the alternator, wherein the one or more blower motors and the at least one traction motor are configured to receive three-phase power from the alternator;
• a plurality of fuses, each fuse being positioned between the alternator and one of the one or more blower motors for each phase of the three-phase power;
• a plurality of current transformer devices, the plurality of current transformer devices comprising a current transformer device for each phase of each of the one or more blower motors, each current transformer device comprising a switch that is normally in a first position, wherein each current transformer device is configured to monitor an output current of one of the plurality of fuses, compare the output current to a threshold current level, and, when the output current is below the threshold current level, change the switch to a second position;
• and
• a processing circuit configured to determine whether one or more of the switches of the plurality of current transformer devices is in the second position, and wherein, when one or more of the switches of the plurality of current transformer devices is determined to be in the second position, the processing circuit is configured to cause a fault condition to be activated.

A method of protecting one or more motors of a vehicle, the one or more motors configured to receive three-phase power from an alternator of the vehicle, wherein the vehicle includes a plurality of fuses, each fuse being provided between the alternator and one of the one or more motors of the vehicle for each phase of the three-phase power, the method comprising:

• monitoring, using a plurality of current transformer devices, output current from the plurality of fuses, wherein the plurality of current transformer devices comprises a current transformer device for each phase of each of the one or more motors of the vehicle and each current transformer device comprises a switch that is normally in a first position, and wherein monitoring output current from the plurality of fuses comprises using a separate current transformer device to monitor an output current of each of the plurality of fuses;
• comparing, at each of the plurality of current transformer devices, the output current to a threshold current level;
• changing, for each of the current transformer devices, the switch of the current transformer device to a second position when the output current is below the threshold current level;
• determining, using a processing circuit configured to control operation of the one or more motors, whether one or more of the switches of the plurality of current transformer devices is in the second position;
• and
• activating a fault condition when one or more of the switches of the plurality of current transformer devices is determined to be in the second position.