Infeed: Line phase failure

What does 206200 mean?

One or several line phases have failed, or an overvoltage condition has persisted, causing the infeed to fault. This can occur during power-on if the PLL cannot synchronize due to incorrect phase assignment (e.g., with a VSM) or during operation after a significant voltage dip or overvoltage. Alarm A06205 usually precedes this fault, providing additional diagnostic information.

• Loss of one or more phases in the incoming AC line supply (e.g., blown fuse, tripped circuit breaker, utility outage).
• Loose or open connection on one or more phases in the power distribution path (e.g., main contactor, terminal block, input reactor).
• Incorrect phase sequence or phase rotation detected by the infeed unit (e.g., L1, L2, L3 connected as L1, L3, L2) preventing PLL synchronization.
• Significant imbalance in the line voltages between phases, exceeding the infeed unit's tolerance for operation.
• Infeed unit internal hardware fault in the phase detection or PLL synchronization circuit.

Click steps to track your progress.

1. 1

   1. Measure the voltage between all three phases (L1-L2, L2-L3, L3-L1) and each phase to ground at the infeed input terminals (e.g., X1) to confirm all phases are present and balanced.

2. 2

   2. Check all upstream fuses and circuit breakers protecting the infeed unit, verifying their continuity and reset status.

3. 3

   3. Inspect all power connections from the main breaker through any contactors, reactors, and to the infeed unit for tightness and continuity.

4. 4

   4. Verify the phase sequence of the incoming supply using a phase rotation meter, ensuring it matches the infeed unit's expected sequence.

5. 5

   5. Monitor parameters related to line voltage (e.g., r0025 for line voltage, r0027 for phase status) after power-on to observe PLL synchronization attempts.