NEC 517.34 & 35 - Control circuits for VAV boxes

[Shujinko]

I have three (3) 120V/1PH circuits that I need to put on equipment branch power in a Hospital Telecom Room. These circuits are for controls for Variable air Volume (VAV) boxes and this is just for controls. The associated Air handling units are on the equipment branch of the Essential Electrical System and these AHU's cool multiple areas of a patient unit in a Hospital. I do not have a 120V/1PH equipment branch circuit close to the VAV control headend boxes in the TR Room. I do have a critical branch circuit panel very close by (within the TR Room) that I would like to use. I interpret NEC 517.34 (7) & (9) as allowing me to do this as these VAV controls are "needed for effective facility operation". Does anyone have some insight or additional code citations to help me with this? I appreciate the help.

 

[RWC/NC.]

(TR Room).. Are we talking "Trama Room" (?) Can you associate the named TR room application w/ anything in named designation (room description) regarding 517.34 (A)(1) through (9). .?

517.35 appears automatically restored in (denoting appropriate time-lag) Delayed Automatic Connection., until the denoted 517.35(A)(6) if delayed automatic connection is not appropriate, then "shall be permitted" placed on critical branch.

 

[RWC/NC.]

Re-reading posting again, 517.34(A)(6) Telecommunications Equipment Rooms and equipment in these rooms. Understanding that Telecommunication equipment operating environments, need maintain certain room temperature for equipment efficiently reliability. But your associated "air-handing units" are being powered by the equipment branch, which again is governed by "appropriate time-lag", equipment branch outside of the "10 second or less" window ? (critical & life safety). I'm making an attempt to justify the power for VAV's on critical branch power, but still coming up short..

 

[garbo]

I retired from a large hospital that said they had rules for what could & could not be connected to the various emergency panels. They were supposed to be posted on a computer file but none of the 6 electricians could ever locate them. Felt like a mushroom you know keep me in the dark and feed me BS. Spent my last 10 years in the trade there and could not figure out why some bosses do not want their workers knowing too much. My dad was a Chief electrician for almost 30 years and would fully explain everything. He keep various information in copy books ( Ya Pre computers ) and left them out for anybody to read. He said anybody could steal my job but nobody can steal my knowledge. The few times at this hospital that I brought up something against what they called hospital policy it was ignored so I stopped speaking up. Worst case was when they installed LED luminares in nurse hallway bump outs. They luminare cover touched the sheetrock ceiling and there was no way to ever replace the LED or driver. We called them the $2,000 two foot LED'S. Had to get a union electrician to cut out sheetrock to replace luminare then hire a union carpenter to repair & spackle sheet rock and finally hire a union painter to paint new sheetrock. Of course they ordered more of these on next remodel area. Had 5 coworkers and a union electrician look at these luminares to try to figure out how to relamp. Intelligent project engineer said that these LED'S last forever. ( Were on 24/7 ) In some areas of this hospital the numerous receptacles that we installed at nurses station for nurses special phones ( only worked in & maybe 500' from hospital )were confusing. Some went into emergency power ( red HR receptacles while others on normal power. This hospital had lots of money and went overboard every where. While JACHO or some other code only required 50% of the elevators be on emergency power they had enough power from the 7 generators that all 21 elevators were on emergency power. Where they had 4 elevators at one location would use two ATS 's rather then one. Had think it was ATS'S on 6 different floors.