Trane Tracer Summit Hardware And Software Installation Manual page 98

IntelliPak Rooftop Unit Interface
To connect shield:
Connect the shield at the BCU (TB2) to provide a drain for RFI/EMI, and
then splice it with other IntelliPak shields at the IntelliPak end. Tape the
shield at the last IntelliPak in the chain to prevent any connection
between the shield and ground (see Figure 42 on page 86). Observe the
polarity throughout communication links.
IMPORTANT
UCM ground loops will cause a malfunction.
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