Hermetic room air-conditioners

[TSET]

In my research, I cannot find a rule that would indicate that hermetic room air-cond.s would be subject to the requirements of 430.24 [see 440.3(B)]. Is it possible that Annex D example D1(b) pre-dates rule 440?[see the italic reference to 430.24 in the example] I've called two repair service outfits, and verified that room a/c is, without exception, hermetic.

Thoughts?

[ November 03, 2005, 12:38 PM: Message edited by: TSET ]

 

[Wes G]

Re: Hermetic room air-conditioners

Originally posted by TSET:
In my research, I cannot find a rule that would indicate that hermetic room air-cond.s would be subject to the requirements of 430.24 [see 440.3(B)]. Is it possible that Annex D example D1(b) pre-dates rule 440?[see the italic reference to 430.24 in the example] I've called two repair service outfits, and verified that room a/c is, without exception, hermetic.

Thoughts?

Partially right! See 440.62(A)(4) and 440.32 for branch circuits.

Annex D1(b) is for feeders , standard calculation, not branch circuits. D2(b) for feeders, optional method, does not use the 125% rule.


___________________
Wes Gerrans
Instructor
Northwest Kansas technical College
Goodland, KS

 

[TSET]

Re: Hermetic room air-conditioners

Yes, thanks Wes. I wish I could use the optional method, but the test question calls for the standard calc on two questions, one being a duplex, and one a five unit. I know that ex. D1 a&b deals with a SFD, but there are no annex D examples that give A/C loads in MFD standard calcs, so I cannot follow the advice of Labor & Industries to look at the examples for the proper technique. I am trying to calculate the service size for these questions, so calcs would be for feeders as opposed to branch circuits. My head has been spinning trying to figure out why L & I failed me since they directed me to annex D, and I know that I followed that protocol.
I can still only assume that the first example predates a later,more specific code alteration to 440[ie.,440.3(B)]

[ November 03, 2005, 01:33 PM: Message edited by: TSET ]