MIL-S-4040 Solenoid, Electrical General Specification ForThis specification covers the general requirements for electrical solenoids used to actuate various devices through the conversion of electrical signals into mechanical motion. These solenoids are of the axial stroke type and the rotary stroke type.

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MIL-S-4040G

d. Measurements after shock: Following this test, the operating force (torque), compensated actuating voltage, and deactuating voltage shall be tested as specified in 4.7.2.1, 4.7.2.2, and 4.7.2.3, respectively. There shall be no evidence of mechanical or electrical damage or impairment of the operation of the solenoid.

4.7.12 Acceleration (see 3.6.5). The solenoids shall be rigidly mounted on the centrifuge and then subjected to an acceleration force of 10 g's in both directions in three mutually perpendicular axes, one of which is parallel to the longitudinal axis of the solenoid coil. During the test, the solenoids shall deliver the specified actuating force within the specified voltage limits (see 3.1).

4.7.13 Moisture resistance (see 3.6.6). Solenoids shall be tested in accordance with method 106 of MIL-STD-202 . The following details shall apply:

a. Mounting: On a corrosion-resistant metal panel using normal mounting means. b. Initial measurement: Insulation resistance as specified in 4.7.3.

c. Polarization: During steps 1 to 6 inclusive, 100 V dc shall be applied between the coil (positive) and the mounting frame (negative) of one-half of the solenoids. Within 5 minutes after the end of the conditioning, the operating force (torque) shall be tested as specified in 4.7.2.1.

d. Final measurements: After a 24 hour drying period at a relative humidity of 50 percent ± 5 percent, solenoids shall be inspected for evidence of breaking, cracking, spalling, and loosening of the terminals. The insulation resistance, operating force (torque), compensated actuating voltage, and deactuating voltage (or current) shall then be tested as specified in 4.7.3, 4.7.2.1, 4.7.2.2, and 4.7.2.3, respectively.

4.7.14 Altitude (see 3.6.7). Solenoids shall be tested in accordance with method 105 of MIL-STD-202 . The following details shall apply:

a. Mounting: Solenoids shall be rigidly mounted by their normal mounting means. b. Test condition letter: See 3.1.

c. Tests during subjection to reduced pressure: With the complete solenoid at stabilized ambient temperature of 25°C ±2°C, measure the coil resistance with ±0.5 percent accuracy. Then, with pressure reduced to the specified altitude and the ambient temperature specified for altitude conditions (see 3.1), the solenoid, with the coil energized with maximum rated voltage, shall be subjected to the specified conditions for a

minimum of two hours. The duty cycle of intermittent duty solenoids shall be as specified in 3.1. Within the last 5 minutes to 10 minutes of the exposure to reduced pressure, the coil resistance shall be measured in

order to enable calculation of the coil temperature. The calculated coil temperature shall be within the temperature limits of the coil magnet wire. Immediately following the coil resistance measurement, the

compensated actuating voltage shall be tested as specified in 4.7.2.2 with the solenoid in its normal attitude. Immediately following the compensated actuating voltage test, the dielectric withstanding voltage

shall be tested as specified in 4.7.4.2 at maximum rated altitude. After return to room temperature and sea level pressure, the insulation resistance, operating force (torque), compensated actuating voltage, and

deactuating voltage (or current) shall be tested as specified in 4.7.3, 4.7.2.1, 4.7.2.2, and 4.7.2.3, respectively.

4.7.15 High temperature (see 3.6.8). The solenoid shall be energized with rated voltage and 98 percent to 102 percent of rated load, and shall be subjected to maximum rated ambient temperature and maximum rated altitude for a period of two hours. Immediately at the end of the conditioning, and while in the specified ambient temperature, the operating force test specified in 4.7.2.1 shall be performed.

4.7.16 Low temperature (see 3.6.9). The deenergized solenoid shall be subjected to the specified minimum temperature condition (see 3.1) for at least four hours. At the end of the conditioning, and while still subjected to the low temperature, with minimum rated voltage applied, the operating force test specified in 4.7.2.1 shall be performed.