4     CompactLogix Packaged Controllers
Publication 1769-IN082A-EN-P - July 2008
Prevent Electrostatic Discharge
Before You Begin
This section contains information you should understand before installing the 
CompactLogix packaged controller.
Restrictions
The maximum amount of expansion modules that can be used with the packaged 
controllers is two. Within that limit, the number of expansion I/O modules that can 
be attached to the packaged controller depends on the bus current draw of the 
modules being attached.
Each packaged controller has a specified amount of available bus current as shown 
in this table.
To determine the number of expansion I/O modules you can add, total the bus 
current draw (maximum) of your planned expansion I/O modules and the end cap. 
If your result is less than the packaged controller’s maximum available bus current, 
you are within the expansion I/O limit of your packaged controller.
ATTENTION
This equipment is sensitive to electrostatic discharge, which can cause internal damage 
and affect normal operation. Follow these guidelines when you handle this equipment:
• Touch a grounded object to discharge potential static.
• Wear an approved grounding wriststrap.
• Do not touch connectors or pins on component boards.
• Do not touch circuit components inside the equipment.
• Use a static-safe workstation, if available.
• Store the equipment in appropriate static-safe packaging when not in use.
Packaged Controller Bus Current and Expansion Module Limits
Cat. No. Total Available 5V DC Bus Current
1769-L23E-QB1B 1 A (1000 mA)
1769-L23E-QBFC1B 450 mA
1769-L23-QBFC1B 800 mA