The ECW-F(A) series tends to fail in open mode rather than short mode in AC Step-up breakdown test. Failure in short mode can result in smoke and fire, a significant quality problem in any design. In a moisture resistance test 1 in 3 of a competitor’s parts failed in short mode (64h) while the ECW-F(A) saw only a reduction in capacitance [delta C/C 6.7% (avg)., IR=25G Ohm (Avg.)].