Solid State Drive Control Questions and Answers

Answer: C

Certified circuitry inhibits the gate drives by two independent channels, which achieves a safe torque-off without the maintenance and wear of a main contactor. Holding a load, by contrast, still needs a mechanical brake.

Answer: D

Correct answer: leaves the dc link charged

Safe torque off removes the gate drive signals so that the inverter cannot produce torque, but it does not disconnect the supply or discharge the link, which remains at several hundred volts. It is therefore a safeguard against unexpected movement and not an isolation: work on the power circuit still requires the supply to be locked off.

Answer: A

Both are wear-out items with lives measured in years and strongly dependent on temperature, whereas the semiconductors and the electronics usually outlast the installation. Planned replacement of both is cheaper than an unplanned failure.

Answer: B

Dust on a heatsink raises the thermal resistance and a failing fan raises it further, and both are easily checked. Devices are replaced on failure rather than on a schedule, and the firmware is left alone unless there is a reason to change it.