Dwelling 24 Volts

Status
Not open for further replies.
tortuga said:
I agree with these good points. However if they want insurance on the structure the AHJ may not just be the local building official but also the insurance co. I would focus on 90.1(A) and (B) the job of the NEC is not to select a voltage or system other than for practical safeguarding of persons and property.
The issue of 'Additional dwelling units' (ADU), 'Tiny Homes', Cabins, Yurts whatever they call it. I'd say 'small dwelling unit' it is upon us (the NEC).
I would be careful to go by the NEC definition of a dwelling unit "Dwelling Unit. A single unit, providing complete and inde-
pendent living facilities for one or more persons, including permanent provisions for living, sleeping, cooking, and sanitation."
If its a hunting cabin with a detached outhouse for sanitation you dont have a dwelling unit.

I'd say article 230 is your minimum design requirement IF your using standard systems. And if you dont have voltage's recognized by NEC 220.5 and they are equal to or lower than the limits in 210.6 (it does not specify AC so DC is included)
And if our 24V (AC or DC) dwelling is a dwelling unit per NEC
I would look at article 411, and the historical article 720 that used to cover such rural 32V Delco systems in the days before grid service.
http://www.doctordelco.com/Dr._Delco/Delco-Light/Delco-Light.html
We could also pretend there were wheels on it and inspect it as a 'Recreational Vehicle' ART 551. And if there was no desire to supply 120V or 240V appliances in the future lots of that would not apply. But that's where I would go.
just my two cents
Cheers
Click to expand...
And that comes back to what is the standard that must be met. If it is to be the NEC, and it does meet the NEC definition of a dwelling unit, 210.52 is a major hurdle to overcome if you don't have 120 volts in your supply system.

Similar question has come up here before - can't remember how long ago it has been, but was regarding wiring a dwelling in accordance with NEC in a country where typical utilization voltage is 240 volt two wire. This was the same problem with that install - how do you comply with all the required receptacles by NEC that are supposed to be 125 volts?
 
kwired said:
And that comes back to what is the standard that must be met. If it is to be the NEC, and it does meet the NEC definition of a dwelling unit, 210.52 is a major hurdle to overcome if you don't have 120 volts in your supply system.

Similar question has come up here before - can't remember how long ago it has been, but was regarding wiring a dwelling in accordance with NEC in a country where typical utilization voltage is 240 volt two wire. This was the same problem with that install - how do you comply with all the required receptacles by NEC that are supposed to be 125 volts?
Click to expand...
Chapter 7 modifies chapters 1-3 so an "Article 720" residence is exempt from 210. This has always be the intent of 720, see NEC 1930 Article 40 "Isolated Plants 0-50 Volts" that is what became today's 720.

Older versions of article 720 required 320 Watts max load per branch circuit and 8 lamp holders maximum, required 10Awg and dedicated circuits for appliances and grounding of one leg of outdoor conductors.
(See 7204 1947 NEC)

If you ever get to crawl in an attic of a turn of the century home and find remnants of 12 and 10AWG knob and tube wiring chances are it was for 32V lighting and appliances. Finding such large conductors in attics of old homes (including my own) is what made me curious. Especially when the homes were built 20 years before the area was connected to the grid.
 
tortuga said:
Chapter 7 modifies chapters 1-3 so an "Article 720" residence is exempt from 210. This has always be the intent of 720, see NEC 1930 Article 40 "Isolated Plants 0-50 Volts" that is what became today's 720.

Older versions of article 720 required 320 Watts max load per branch circuit and 8 lamp holders maximum, required 10Awg and dedicated circuits for appliances and grounding of one leg of outdoor conductors.
(See 7204 1947 NEC)

If you ever get to crawl in an attic of a turn of the century home and find remnants of 12 and 10AWG knob and tube wiring chances are it was for 32V lighting and appliances. Finding such large conductors in attics of old homes (including my own) is what made me curious. Especially when the homes were built 20 years before the area was connected to the grid.
Click to expand...
The remnants I run into were switched over to 120 volts when utility power came along. This is common on old rural farmhouses - if they still have original wiring intact. Rural electrification act was passed in 1936, many of these homes around here didn't get utility power until well into 1940's.
 
kwired said:
The remnants I run into were switched over to 120 volts when utility power came along. This is common on old rural farmhouses - if they still have original wiring intact. Rural electrification act was passed in 1936, many of these homes around here didn't get utility power until well into 1940's.
Click to expand...
Yeah Oregon was an early adopter of electricity but the 32V Delco systems cost far less and could be also wired to a wind mill. I believe it was some combination of 2 Volt lead acid cells, a generator that only ran for charging and the option to add the wind mill.
I was quite surprised to learn they had 32V radio's, coffee makers and vacuum cleaners.
 
I have but one word to say: Boat. Many live aboard. Stick a keel on your cabin in the woods, and a tiller rename it with a catchy sailor name, and you should be good to go........ And shout out Ahoy Matey when the building inspector's show up
 
Status
Not open for further replies.
Top