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Unread 16-10-2008, 10:36
Russ Beavis Russ Beavis is offline
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Re: chassis isolation, contrary to UL1740?

On the Power Distribution module (aka PD), there is a 1.1A (hold), 2.2A (trip) PTC (Positive Temperature Coefficient) "breaker" in the return path for the 24V supply for cRIO. That device will limit current "through" the cRIO chassis to only a few Amps.

How will we inspect for chassis isolation since every team that mounts a cRIO to a metal chassis will have an intentional low impedance connection to ground? We haven't figured out the details yet but we'll probably need to unplug the cRIO from its power supply when performing the standard chassis isolation test.

Russ