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TB052 Rev1 Foam Filter Maintenance
Some M400 systems shipped in 1998 have a type of filter foam that can prohibit proper airflow through the
system On these systems closed cell foam was used in place of open cell foam The foam can be identified
by looking or blowing thru it Open cell foam will allow air and light to pass through freely while the closed cell
foam doesn't allow as much light to pass through as compared to the open cell foam Systems that have the
closed cell filter foam should have it removed and replaced as soon as possible Replacement filters can be
obtained through Centroid or common furnace and air conditioning suppliers Filter foam may be obtained
locally and cut to fit
There are three locations where the filter foam may be located The first area is located on the main electrical
cabinet door fan located in the lower right corner of the electrical enclosure door The second area is located
on the inside of the electrical cabinet door and covers the exhaust louvers The third area is located on back of
the M400 console for the fan and screen Filter foam that covers exhaust louvers should be glued in place with
rubber cement The door fan and console fan and screen need removed and have replacement filter foam cut
to size See figures 1 and 2 Centroid recommends that the filter foam be replaced every 90 days to maintain a
good airflow With the release of CNC10 version 1 10 the control will remind customers every 90 days to
clean/replace all foam air filters
Document History
Rev1 Created on 1998 10 07