When powering the MMR, what is the required power sequence and delay?

• A. DC, 20 Seconds, AC
• B. AC, 10 Seconds, DC
• C. AC, 5 Seconds, DC
• D. DC, 15 Seconds, AC

Answer: (B)

The key idea is powering the MMR in a controlled order so the internal power supplies and control circuits stabilize before the main DC rails come online. Apply AC power first to energize the primary regulators and allow voltages to settle. After a 10-second delay, switch to DC power to feed the regulated rails and enable the system. That 10-second interval gives time for voltages to reach nominal levels and for any startup checks to complete, reducing transients and protecting components. Starting with DC can bypass the conditioning the AC startup provides and may trigger protection or result in unstable rails, and the other delay timings either don’t allow enough stabilization or add unnecessary wait, making AC followed by DC after 10 seconds the correct approach.