Spectrum Controls 1746sc-INI4vi - Manual (Page 17)

Chapter 2: Installing And Wiring Your Module 13
Selecting A Rack Slot Two factors determine where you should install your module in the rack:
ambient temperature and electrical noise. When selecting a slot for your
module, try to position your module:
• in a rack close to the bottom of the enclosure (since hot air rises)
• away from modules that generate significant heat, such as 32-point
input/output modules
• in a slot away from ac or high-voltage dc modules, hard contact
switches, relays, and ac motor drives
• away from the rack power supply (if using a modular system)
Remember that in a modular system, the processor always occupies the
first slot of the first rack.
Inserting Your Module
Into The Rack
CAUTION
POSSIBLE EQUIPMENT OPERATION
Before installing or removing your module, always
disconnect power from the SLC 500 system and from any
other source to the module (in other words, don’t “hot
swap” your module), and disconnect any devices wired to
the module.
Failure to observe this precaution can cause unintended
equipment operation and damage.
When inserting your module into the rack, you do not need to remove the
supplied 16-position terminal block from the module. If, however, you do
remove the terminal block, apply the supplied write-on label to the
terminal block, and use the write-on label to identify your module’s
location.
To remove the terminal block, unscrew the two retaining screws at the
top and bottom of the terminal block, and using needle-nose pliers,
carefully pry the terminal block loose.
To insert your module into the rack, follow these steps:
1. Align the circuit board of your module with the card guides at the top
and bottom of the chassis.
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