🔍 Key Concepts

• Follow the power flow from the supply, through the protection device, to the motor and contactor coil • Distinguish between electrical problems (motor won’t run at all) and hydraulic problems (motor runs but system pressure/flow is wrong) • Use the schematic symbols in GS-0161 to locate the control power feed to the motor starter

💭 Think About

• If you press the start button and the motor does not even attempt to start, what is the simplest thing that could be interrupting power to the entire controller? • Which listed components would affect motor rotation or hydraulic pressure only after the motor is already running, and which one would prevent any operation at all? • Looking at the diagram, which device is placed closest to the incoming power, ahead of the contactor coil and motor starter?

✅ Before You Answer

• Confirm which option is an electrical protective device for the entire controller, not a hydraulic component • Eliminate any options that only influence hydraulic pressure or flow after the pump is turning • Verify on the diagram which component must be closed/energized before the contactor coil can receive power