Article 645

[tbassler_99]

I am having a disagreement with a local inspector about requiring my server room to have shunt trips installed. My electrician says installing it now will cost a few thousand dollars and it wasn't in my original design. The room does have separate HVAC, but I say it doesnt apply as an ITT room because there is no shunt trip installed.

I believe the requirements of 645 amend the first four articles of the code to have less stringent rrequirements for these rooms provided they comply with NFPA 75 and the first four requirements of 645.2 are satisfied. The inspector says no, I am using circular logic because 645.10 requires a disconnect and I say neither it nor the rest of article 645 apply because 645.2 isn't met. Can anyone offer some adivce?

 

[e57]

My understanding is that all of 645 is optional - if you gain some other benefit out of the rest of that code that would allow other design, or fire protection. Say cables under the floor panels - exit and entry etc. Battery storage... Fire Marshal requiring it....I have had that before...

Some other info:
http://www.csemag.com/article/CA6290839.html
www.apcmedia.com/salestools/ASTE-5T3TTT_R2_EN.pdf
http://www.abrconsulting.com/art645-2.htm

Also - shunt trips are not the only way to do it - a contactor can work just as well IMO.

 

[ron]

Article 645 only applies if you comply with 645.4(1) through (5). If you don't have a disconnecting means listed under (1), then you can't use Article 645. Good for you. It's not worth the headache.

I like this guy's article below. He seems like a nice guy.
www.csemag.com/article/CA6290839.html

 

[jerm]

I like this guy's article below. He seems like a nice guy.
http://www.csemag.com/article/CA6290839.html

That's a great article. Print that out and take it to your inspector.

 

[e57]

Article 645 only applies if you comply with 645.4(1) through (5). If you don't have a disconnecting means listed under (1), then you can't use Article 645. Good for you. It's not worth the headache.

I like this guy's article below. He seems like a nice guy.
www.csemag.com/article/CA6290839.htmlhttp://www.csemag.com/article/CA6290839.html

Yeah I was looking for that one and it seems you beat me to it....

 

[tbassler_99]

Thanks

Thanks

Thanks to everyone! I thought I understood it correctly, but sometimes you can't win those arguments with certain "knowledgable" inspectors. That is an excellent article and I plan to have my electrician do exactly that. I do of course plant to follow up and let you know how it ends up. Thanks again.