Fagor alarm E301: Over-temperature at the Ballast circuit of the power supply or compact module
DDS drive display code (seven-segment; PS/XPS/RPS power supplies) · Fagor PS/XPS/RPS
What it means
The ballast (braking-energy dissipation) circuit heatsink exceeded its limit on the power supply or compact drive. Heavy deceleration duty keeps dumping energy into the ballast, so repeated trips point to undersized or failing dissipation. Stop several minutes, reduce cycle demand and check ballast health.
Likely causes
- ballast resistor bank aging/derating (values drifted high)
- excessive braking duty (vertical axes, short reversals)
- ballast fan (ER+TH-18/x+FAN type) stopped
- i2t selector switches set for a smaller resistor than fitted
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
- Request a quote →
ER+TH-x/x ballast resistor module
regen-resistor · Common cause
- Request a quote →
Fan for ER+TH-18/x+FAN ballast module
fan · Common cause
Need the part urgently?
Send us alarm E301 with your machine details — typical RFQ turnaround is 24–48h.