Honeywell Low Voltage RTP Cable (2.5M, 8.2ft.) Note 6 (NOT FOR SIL2 SYSTEMS) 900RTC-L125
Ensure that AC power to the 
rack is disconnected.
Set controller module’s 
communication ports to 
desired settings (page 42).
Carefully place the Controller 
Module in the rack, 
immediately to the right of 
the Power Supply. Fasten it 
in place with two captured 
screws at top and bottom.
Torque to 0,4-0,5 N.m
(3.5 – 4.4 Lb-In).
ATTENTION:
Do not install the battery at 
this time. Installing the 
battery(s) before the 
controller is configured 
can substantially shorten 
battery life. Install under 
power after the controller 
configuration is complete.
(For more information, refer 
to Battery 
Installation/Replacement, 
page 203.)
4 I/O will be installed later. See Page 77.

Table 10 – Assemble C75 Controller Rack
Step Procedure Comments/References
1 Carefully place the Power 
Supplies in the slots in the 
Rack, ensuring that the 
connector at the back seats 
properly. See Table 9 steps 1 
and 2 for power supply wiring 
details. 
Note: It is recommended each 
power supply should be 
powered from a separate 
power source and a power 
switch should be installed to 
allow for servicing of each 
Processor/Supply separately. 
2 Set controller communication 
ports.
3
Ensure that AC power to the 
rack is disconnected.
Carefully place the Controller 
Modules in the rack, adjacent 
to the Power Supplies. 
Fasten them in place with 
captured screws at top and 
bottom.
Torque to 0,4 -0,5 N.m
(3.5 – 4.4 Lb-In).
ATTENTION:
The CPU battery comes 
installed with a plastic tab 
protruding from the battery 
cover. This tab breaks the 
battery circuit. Do not 
remove this tab at this time. 
Removing the tab before 
the controller is configured 
can substantially shorten 
battery life. Remove the tab 
under power after the 
controller configuration is 
complete.
(For more information, refer to 
Battery 
Installation/Replacement, 
page 203.)
See figure in step 1.
4 Insert the RSM in the middle 
slot and attach with screws at 
top and bottom.
See figure in step 1
Assemble I/O Expansion Racks
I/O Expansion Rack assembly information is given in Table 11.
Table 11 – Assemble I/O Expansion Racks
Step Procedure Comments/References
1 Insert power supply into left-most slot 
in the I/O rack. See Table 9 steps 1 
and 2 for wiring details. 
If using redundant power, your I/O rack will contain a second 
smaller compartment, see 1 in the following figure. Insert first 
power supply in the larger compartment as shown, to the 
immediate right of the plate dividing the two compartments.
2 Redundant Power (optional):
Insert the second power supply in the 
left side of the smaller compartment, 
see 1 in figure above. See Table 9
steps 1 and 2 for details.
Insert the PSM between the 2 power 
supplies. Fasten it in place with 
screws at top and bottom.
See 1 in figure above. See Table 9 steps 1 and 2 for wiring 
details.