90    HC900 Process & Safety Controller User and Installation Manual  Revision 6 
    21 April 2017 
Install I/O modules in 
racks. Be sure to follow 
placement guidelines 
under Heat Rise De-rating 
page 52. 
Install I/O module, install 
appropriate terminal block. 
In each slot location not 
occupied by an I/O 
module, install a Filler 
Block cover, Part number 
900TNF-0001. 
Note: The Filler Block Cover looks much like an I/O Terminal 
Block assembly, except that it does not include the wire 
terminating block (screw terminals).  The Filler Block mounts in 
the same manner as a Terminal Block (with captured screws at 
top and bottom).  Blank labels are provided for mounting in the 
hinged door.