Dust and Particulate Requirements
Exhaust fans cool power supplies and system fans cool fabric interconnects by drawing in air and exhausting
air out through various openings in the chassis. However, fans also ingest dust and other particles, causing
contaminant buildup in the fabric interconnect and increased internal chassis temperature. Dust and particles
can act as insulators and interfere with the mechanical components in the fabric interconnect. A clean operating
environment can greatly reduce the negative effects of dust and other particles.
In addition to keeping your environment free of dust and particles, follow these precautions to avoid
contamination of your fabric interconnect:
• Do not permit smoking near the fabric interconnect.
• Do not permit food or drink near the fabric interconnect.
Minimizing Electromagnetic and Radio Frequency Interference
Electromagnetic interference (EMI) and radio frequency interference (RFI) from the fabric interconnect can
adversely affect other devices, such as radio and television (TV) receivers. Radio frequencies that emanate
from the fabric interconnect can also interfere with cordless and low-power telephones. Conversely, RFI from
high-power telephones can cause spurious characters to appear on the fabric interconnect monitor.
RFI is defined as any EMI with a frequency above 10 kHz. This type of interference can travel from the fabric
interconnect to other devices through the power cable and power source or through the air as transmitted radio
waves. The Federal Communications Commission (FCC) publishes specific regulations to limit the amount
of EMI and RFI that are emitted by computing equipment. Each fabric interconnect meets these FCC regulations.
To reduce the possibility of EMI and RFI, follow these guidelines:
• Cover all open expansion slots with a blank filler plate.
• Always use shielded cables with metal connector shells for attaching peripherals to the fabric interconnect.
When wires are run for any significant distance in an electromagnetic field, interference can occur to the
signals on the wires with the following implications:
• Bad wiring can result in radio interference emanating from the plant wiring.
• Strong EMI, especially when it is caused by lightning or radio transmitters, can destroy the signal drivers
and receivers in the chassis and even create an electrical hazard by conducting power surges through
lines into equipment.
To predict and prevent strong EMI, you need to consult experts in radio frequency interference (RFI).
Note
The wiring is unlikely to emit radio interference if you use a twisted-pair cable with a good distribution of
grounding conductors. If you exceed the recommended distances, use a high-quality twisted-pair cable with
one ground conductor for each data signal when applicable.
Preparing for Installation
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Preparing for Installation
Dust and Particulate Requirements
