(2) The protective entrance provides a pressurized transition area between the shelter and the outside
contaminated zone. Personnel entering from the outside must wait 5 minutes within the protective entrance
before entering the shelter. Contamination is purged by the flow of filtered air. The PECM automatically ad-
justs the airflow valve and silencer assembly to maintain the proper air pressure inside the protective entrance.
d. CPE System Configurations. Collective protection equipment is configured to fit the needs of a specific
application and may differ from the typical system discussed above.
TYPICAL CPE CONFIGURATION