Cleanrooms require a high level of security, with limited access to authorized personnel only. To help prevent contamination, it is important that a cleanroom’s sterile environment be protected by a dependable access control system. Available advanced interlock controls can work with any access control systems that may be in use in controlled environments.

Today’s programmable logic controllers (PLCs) easily manage the operation of door locks, automatic door openers, air dampers, and indicator lights. These pre-programmed controllers allow facility operators to manage from two to over 100 doors in any combination, and allow only one door at a time, in a designated area, to be accessed.

Much thought and preplanning should go into the operation specification. The design engineer should be well versed in the local code requirements and select an interlock product from a recognized, established manufacturer familiar with cleanroom operations. When possible, contact the interlock manufacturer when writing the system description to specify the most current products. Factory programmed and tested PLC-based interlock controllers allow greater flexibility of operations while simplifying the specifying of appropriate devices. Having a single source for the controls and locking hardware also assures compatibility.
 

This cleanroom tip was taken from “Clean, Secure Access,” which appeared in the November/December 2012 issue of Controlled Environments.