USCG Exam PracticeMotor controllers and remote control
According to 46 CFR §111.70-7, a controller must be designed so that an accidental ground in a remote control circuit does NOT cause which of the following conditions?
- ✓ The stop switches to fail to operate or the motor to start unintentionallyCorrect
- B. The overload relay to trip and de-energize the contactor coil
- C. The branch circuit overcurrent device to open and interrupt power
- D. The seal-in contact to drop out and require manual restart
Why A is correct
46 CFR §111.70-7(b) specifically requires the controller to be designed to prevent an accidental ground in a remote control circuit from causing stop switches to fail to operate or the motor to start. The other outcomes listed are normal protective functions, not the failure mode this rule addresses.
Cited:46 CFR §111.70-7