scope:

This specification is mandatory for use by all Departments and Agencies of the Department of Defense.

DO NOT USE FOR NEW DESIGN FOR REPLACEMENT PURPOSES ONLY

This specification covers the general requirements for direct-current (dc) paper-dielectric, fixed capacitors hermetically sealed in metal cases, intended primarily for filter, by-pass, and blocking purposes where the alternating-current (ac) component of the impressed voltage is small with respect to the dc voltage rating. This specification also covers removable mounting brackets for use with the capacitors.

The type designation for capacitors shall be in the following form, and as specified (see 3.1 and 6.1):

The style is identified by the two-letter symbol "CP" followed by a two-digit number; the letters identify direct-current, paper-dielectric, fixed capacitors hermetically sealed in metal cases; the first digit identifies general shape of the case, and the second digit identifies specific details other than case size. Each style designation includes a family of case sizes.

The terminal is identified by a single letter in accordance with table I. TABLE I. Terminal.

Symbol Type of terminal ------------------------------------------------------------- A - - - - - - Axial wire leads. B - - - - - - Solder lug (nonremovable). C - - - - - - Threaded stud and nuts. D - - - - - - Pillar insulator for use at altitudes up to 7,500 feet. Furnished with threaded stud and nuts. E - - - - - - Pillar insulator for use at altitudes up to 50, 000 feet. F - - - - - - Hooked-wire lead.

The circuit diagram and the number of terminals associated with it is identified by a single symbol as shown in table II.

The characteristic is identified by a single letter in accordance with table III. TABLE III. Characteristic.

Values for characteristic A and B E and F K ------------------------------------------------------------------------------------- High ambient test temperature, degrees centigrade 85 85 125 ±3°C - - - - - - - - - - - - - - - - - Low ambient test temperature, degrees centigrade −55 −55 −55 ±3° C - - - - - - - - - - - - - - - - Life-test dc voltage in percent of the voltage rating at 40° C (see 4.6.15): Watt-second group: I: 1A (0.08 watt-second and less) - - - - - - - 190 140 140 1B (0.08 + to 0.5 watt-second) - - - - - - - 190 140 120 II (0.5 + to 5 watt-seconds) - - - - - - - - 170 130 --- III (5 + to 50 watt-seconds) - - - - - - - - --- 110 --- IV (greater than 50 watt-seconds) - - - - - --- 90 ---

The dc voltage rating for continuous operation at 40°C, except for characteristic K, which is 85°C, is identified by a single letter in accordance with table IV (see 6.5). TABLE IV. DC voltage rating.

DC voltage DC voltage Symbol rating Symbol rating ------------------------------------------------ Volts Volts B - - 100 K - - 2,500 C - - 200 L - - 3,000 D - - 250 M - - 4,000 E - - 400 N - - 5,000 F - - 600 P - - 6,000 G - - 1,000 R - - 7,500 H - - 1,500 S - - 10,000 J - - 2,000 T - - 12,500

The nominal capacitance value expressed in picofarads (pf) is identified by a three-digit number; the first two digits represent significant figures and the last digit specifies the number of zeros to follow.

The capacitance in percent is identified by a single letter in accordance with table V. TABLE V. Capacitance tolerance.

Symbol Capacitance tolerance ----------------------------------------- Percent K - - - - ±10 L - - - - ±15 V - - - - +20 −10

The vibration grade is identified by a single digit in accordance with table VI. TABLE VI. Vibration grade.

Symbol Frequency range (Hz) -------------------------------- 1 - - - 10 to 55, incl 3 - - - 10 to 2,000, incl

The type designation for removable mounting brackets shall be in the following form, and as specified (see 3.1 and 6.1):

Brackets for direct-current paper-dielectric, fixed capacitors covered by this specification are identified by the two-letter symbol "CP" followed by a two- or three-digit number. The number is formed by a zero followed by the first digit or both digits of the two-digit case designation assigned to the particular case for which the bracket is intended (see 3.1).

The design of the footed bracket is identified by the letter "F", and of the spade-lug bracket by the letter "S".

The case-size designation corresponds to the case size, as specified (see 3.1).

Capacitors of characteristic K shall have a dc voltage rating for continuous operation at 85°C, and capacitors of all other characteristics shall have a dc voltage rating for continuous operation at 40°C as specified (see 3.1). Voltage derating at other ambient temperatures may be necessary in order to realize equivalent life 1/ (see 3.1, 6.4, and 6.4.1).

The rating given is the steady-state dc voltage, or the sum of the dc voltage and the peak ac voltage, provided that the peak ac voltage does not exceed 20 percent of the rating at 60 Hertz (Hz), 15 percent at 120 Hz, or 1 percent at 10,000 Hz. Where heavy transient or pulse currents are encountered, the requirements of this specification are not sufficient to guarantee satisfactory performance and due allowance must be made, therefore, in the selection of a capacitor.