Ametek Thermox 2000 ATEX Series User Manual page 51

Transient and RFI interference
This section describes transient and RFI interference precautions:
• Although there are transient and noise protectors on all control unit I/
O connections (communications, current outputs, sensor, etc ...), this
protection is intended to act as a last line of defense against unwanted
transient and RFI interference. Proper installation practices to prevent
the introduction of transients and noise into the system must be fol-
lowed. Inductive loads connected to the control unit must have tran-
sient suppressors installed at the inductive loads. Be sure to place the
transient suppressor as close to the load as possible. Examples of tran-
sient suppressors include MOVs, TRANSORBs, and RC snubbers.
• AC mains supply wiring should not be run in the same conduit with
mains supply wiring that feeds heavy inductive loads.
• Avoid running signal wiring in the same cable or conduit with wires
that power inductive loads unless all the cables within the conduit are
shielded, the inductive loads are small, and transient suppressors are
used at the loads.
• Do not run signal lines in the same cable or conduit with high voltage
lines.
• For optimum noise protection, control unit mains supply wiring should
be connected to a circuit separate from any circuit that could intro-
duce transients into the system. As an example, do not run motors,
blowers, or air conditioners using the same mains supply circuit or
conduit as the control unit's mains supply circuit or conduit.
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Installation 3-27