Capacitor types and ratings used to generate a-c and d-c life test data are listed in Table 3.

The CFR types include the two MIL terminations as shown in Figure 6, the lead wire for moderate a-c currents and the lug terminal for high a-c currents. Figure 7 depicts hermetically-sealed metal-case tubular capacitors in accordance wth the industry standard.

Results of life tests are summarized in Tables 4 through 8.

Note the following points from the Tables 4 through 8:

1. Sixty-nine (69) capacitors totaling 540 µF were tested at MIL specified a-c currents at 40 kHz and +85 degrees C for a total of 28,260 unit-hours of operation –with no failures.
2. One hundred eighty (180) capacitors totaling 2260 µF were tested at 140% of rated d-c voltage and +105degrees C for a total of 260,000 unit-hours of operation. One unit failure occurred after 600 hours of the 2000 hour test.
3. Two hundred (200) capacitors totaling 3100 µF were tested at rated d-c voltage and +105degrees C for 400,000 unit-hours of operation with no failures.

Life test results to date indicate the potential for metallized polypropylene capacitors for reliable performance in both a-c and d-c applications.

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