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Power Distribution Modules
STB PDT 3105 Protective Earth Connection
PE Contact for the Island Bus
One of the key functions of a PDM, in addition to distributing sensor and actuator
power to the I/O modules, is the provision of PE to the island. On the bottom of each
STB XBA 2200 PDM base is a captive screw in a plastic block. By tightening this
captive screw, you can make a PE contact with the DIN rail. Every PDM base on the
island bus should make PE contact.
How PE Contact Is Made
PE is brought to the island by a heavy-duty cross-sectional wire, usually a copper
braided cable, 4.2 mm2 (10 gauge) or larger. The wire needs to be tied to a single
grounding point. The ground conductor connects to the bottom of the each PDM
base and is secured by the PE captive screw.
Local electrical codes take precedence over our PE wiring recommendations.
Handling Multiple PE Connections
It is possible that more than one PDM will be used on an island. Each PDM base on
the island will receive a ground conductor and distribute PE as described above.
NOTE: Tie the PE lines from more than one PDM to a single PE ground point in a
star configuration. This will minimize ground loops and excessive current from being
created in PE lines.
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