Fagor alarm E306: Power bus voltage too high (software)
DDS drive display code (seven-segment; PS/XPS/RPS power supplies) · Fagor PS/XPS/RPS
What it means
Software monitoring in the supplying module found the DC bus above its upper threshold — the same condition as E215/E304 but caught by the firmware watchdog. Regenerated energy with nowhere to go is the root cause in nearly all cases. See E304 for the power-supply-side hardware twin of this fault.
Likely causes
- external ballast ER+TH burnt open or its thermostat latched
- ballast selection switches misconfigured on PS-65A
- regen path fault inside XPS/RPS
- steep multi-axis decelerations exceeding dissipation capacity
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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ER+TH-x/x ballast resistor module
regen-resistor · Common cause
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RM-15 ballast resistor module (older PS-25B4 sets)
regen-resistor · Check if others ruled out
Need the part urgently?
Send us alarm E306 with your machine details — typical RFQ turnaround is 24–48h.