chassis isolation, contrary to UL1740?

[Russ Beavis]

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

[Manoel]

Originally Posted by Russ Beavis

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

Mounting your electrical system to a non-conductive surface has always been encouraged, could it be made mandatory for next year?

[EricVanWyk]

Originally Posted by Manoel

Mounting your electrical system to a non-conductive surface has always been encouraged, could it be made mandatory for next year?

It will certainly be mandatory for any of the team I end up mentoring.

[Russ Beavis]

I probably should have included the following disclaimer in my above post -

I don't write the rules. It's possible that FIRST and the GDC may decide to require non-conductive mounting of the cRIO to fully avoid the issue.

Russ

[Richard Wallace]

Originally Posted by Russ Beavis

I probably should have included the following disclaimer in my above post -

I don't write the rules. It's possible that FIRST and the GDC may decide to require non-conductive mounting of the cRIO to fully avoid the issue.

Russ

I would like to see a requirement for non-conductive mounting of the cRIO in the 2009 FRC rules -- but I don't write the rules, either.

Whatever the rule turns out to be, I hope that the rule makers will have it well thought out before January 3rd, 2009.