Component reference

Welder Electrolytic and CBB Capacitor Testing

Capacitor faults affect DC bus storage, snubber behavior, input filtering and power-stage stress.

Component role

Capacitors must be discharged before measurement. Visual evidence is only the first layer; capacitance, ESR, leakage and circuit role matter.

Part	Role	Fault clue
Electrolytic capacitor	DC bus storage and ripple reduction	Bulge, leak, high ESR, weak output or bus ripple.
CBB capacitor	AC filtering, snubber or EMI path	Crack, burn, capacitance loss or snubber stress.
DC bus bank	Energy storage	Breaker trip, fuse blow or unstable inverter startup.