 |
|||
|
|
|||
| ||||||||||
|
| MIL-F-5l539A
4.4.6 Tests. Cycling burn-in and operational characteristics tests shall be conducted as
follows:
4.4.6.1 Preparation for tests. To conduct the following test procedures, a framework of
wood (or other suitable material) shall be fabricated to simulate placement of the filters
within the filter unit housing. With the framework so emplaced, care should be taken to
ensure that the bolts on the outer access cover and the spring loaded retaining bolt on the
yoke are not overtorqued such that component damage results.
4.4.6.2 Cycling burn-in. The filter unit need not be assembled. Test the filter unit, less
gas-particulate filters, by electrically interconnecting the modules for the specified time as
follows:
(a) Connect the filter unit to a source of 208 V, 400 Hz, 3-phase wye power, and
turn the power switch to the ON position.
(b) Connect the hose fitting on the compartment control module to a solenoid actu-
ated vacuum source of 25 2 iwg. The solenoid shall be such that it will alternatively apply
the 25 iwg vacuum source and ambient pressure to the fitting.
(c) Connect the coil of the solenoid to a timer so that the solenoid will actuate at a
rate of 3 times per minute (1 time per minute for the production reliability test, 3 times per
minute for the burnin). Operate the filter unit in this configuration for the specified time
causing the airflow valve to alternately drive fully open and fully closed in response to the
applied pressure signals.
(d) Operate the filter unit for 30 minutes. Then turn the power switch to the OFF
position for 1 minute.
(e) Continue to alternate the power switch ON 30 minutes, OFF 1 minute for the
specified bum-in period.
4.4.6.3 Operational characteristics. Prior to and after the cycling burnin test, the filter
unit shall be inspected to assure that it is still cycling properly and all circuit breakers are
set. Then:
(a) With the power applied as specified in 4.4.6.2(a), disconnect the solenoid/timer
apparatus and connect a manometer and adjustable vacuum source (free of pressure pulsa-
tions) to the hose fitting on the compartment control module. With zero differential pres-
sure applied to the fitting, the airflow valve shall drive fully open, the horn will sound and
the MASK indicator light will flash.
(b) Slowly increase the differential pressure. The horn shall silence and the MASK
indicator shall go out. The airflow valve shall begin to drive closed as specified.
(c) Continue to increase the differential pressure to approximately 2.2 iwg until the
airflow valve is fully closed. Slowly decrease the differential pressure. The airflow valve
shall begin to drive open as specified.
(d) Continue to decrease the differential pressure. The airflow valve shall continue
10
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals