Common sence... right?

[luckylerado]

Installing a 30v system in a tech classroom. There are several work benches that will each be served with a listed jack of some kind to use in troubleshooting electronics.

The rack mounted power supply that I must use has an output of 100 amps at 30v. There are 2 small copper bars sticking out of the back: pos and neg.

Do i need overcurrent protection on the 30v drops to each bench?

Article 720 is the only thing that I can find that applies and it is just a tiny little thing. As far as I can tell I do not fit neatly into any of the sub sections of article 725, 720.2 leads me nowhere and it is not a fire alarm issue.

I am trying to hash this out with the engineer. My argument is that not having some overcurrent protection is not so much an electrocution risk but a fire risk. I am looking for some ammunition.
Thanks

 

[iwire]

Article 240 applies.

 

[BJ Conner]

Crowbar output protection.

Crowbar output protection.

Check the power supply specs. I have seen a lot of them that have a "crowbar" protection on the output. If the current goes to high the ouput shorts out.
It probably has an internal fuse as well.

 

[ptonsparky]

Common sense says that if you have 100 amps available you better have 100 amp wire no matter 12v or 1200v.

 

[iwire]

Common sense says that if you have 100 amps available you better have 100 amp wire no matter 12v or 1200v.

Exactly.

Nothing in Article 720 removes the general requirements of chapters 1 through 4

90.3 Code Arrangement. This Code is divided into the
introduction and nine chapters, as shown in Figure 90.3.
Chapters 1, 2, 3, and 4 apply generally; Chapters 5, 6, and 7
apply to special occupancies, special equipment, or other special
conditions. These latter chapters supplement or modify the
general rules. Chapters 1 through 4 apply except as amended
by Chapters 5, 6, and 7 for the particular conditions.

 

[luckylerado]

90.3 this is the answer i was looking for. Thanks