When does a system become CODE?

[OperaHouse]

I've been here for a while and there hasn't been much discussion about when a system needs to meet code. It has been more of a don't ask, don't tell.  Somewhere between a 12KW system and Chris Olsen's LED in a shed the building department is going to take notice. Certainly many building departments are just as confused and want to see everything electrical just as they do with a conventional grid system whether it ia actually required or not.  And what happens when you build your own controller or windmill and then they want UL approval?

Lets start with a simple case and ignore best practice.  On the roof a 48V string of solar panels.  That feeds down through two #12
with ground with which the panels frames are properly grounded.  The panels can only produce 6A even shorted, well below the current capacity of the cables.  There is no disconnect or fuse at the panels.  There is no connection to the grid, no controller,  no battery,just a connection to a space heater, not even a switch.  Does this violate code?  If so, at what voltage or wattage does that start.

This could be an interesting discussion as we add components to the system.  Something we all have to think about as we move from an experiment to a system.

[DamonHD]

Here in England as soon as you go above 48V nominal, grown-ups have to be involved as far as I know.

There may also be planning requirements to meet, eg for plonking PV on your roof, but that may be outside the scope of what you're asking about.

Rgds

Damon

[XeonPony]

Yes you are in clear violation of code, ANY power system must meet code. Codes are basically the minimum lowest quality job you can legally do, you can do much better then code for efficiency and better safety, but code is the bottom barrel job that can be legally allowed to occur.

there must be a way to isolate the source of power, and a safety device to open in event of over current

ANY THING attached to a permanent structure must meet code more so, back in BC Canada a guy had wired his entire shop via extension cords on hooks as he refused to get an electrical permit on principle and he wanted to rub it in the face of the town, as nothing was "attached" there was nothing for code to say other then branch loading.

All so any permanent system attached to the land must meet strict code, such as buried power lines.

How ever there are codes for detached systems, and must be met or insurance can give a the middle finger should there be a fire.

yours would be a class 2 low voltage system, the fuse would be no more them 100/open voltage of the panels, and must be isolated from any other class of power circuit.

Canadian electrical code: Section 16002 and 16-200 sub pera C or D, and must comply to 16-204 & 16-210 16-222

16-222: On a circuit more then 42.4V peak no live parts may be allowed to be accessible to any one but authorized personnel (You)

[Bruce S]

There should be a few more details here as well.
What might be considered to be a minimum of at what voltage should codes need to be met in a specific Country , may not be the case in another.
Down in our little state of Missouri , we have exceptions to "portable" PV systems and meeting codes for the homes.
My little system is considered exempt for grounding requirements as it is only a 12Vdc system (no worries it is grounded) and the wires that enter my home (water tight and fused) do not have to meet very strict housing safety codes. I checked with both insurance company and city code enforcement officials.
Both sent an inspector  , insurance was 10x more strict than city! OKAY by me, they're the ones covering.
So maybe within this discussion, some of the requirements need to be noted for a specific region?
 
 
 

[Ungrounded Lightning Rod]

In the legislatures in US most jurisdictions start their code by cloning the NEC (National Electrical Code - a private organization's product), maybe with a few local tweaks.  But the real code is how the local inspectors interpret the codes of their district.

Part of the reason for 48V systems is that the NEC has a low-voltage section where many provisions are easier, and the boundary between the low and high voltage sections is 50V (which in turn may be largely because the telecoms standardized on 48V.)  So when you go above 12V (inherited from vehicular systems) the logical place to go is 48V (where you get to inherit economy-of-scale from telecom equipment and are about as high as you can get without going from the moderate to the stringent parts of the electrical code).

[equiluxe]

Here in England as soon as you go above 48V nominal, grown-ups have to be involved as far as I know.

There may also be planning requirements to meet, eg for plonking PV on your roof, but that may be outside the scope of what you're asking about.

Rgds

Damon

My experience building diesel power plant, no building reg's or council involvement is required until the cable reaches the wall. You can have chimps building the generators and control gear as long as that is on the skid they can wire in the unit to the wall switch box after that a certified electrician is required, I have come across some of them who do not even fully understand ohms law let alone what goes on in the gen sets control gear but as they hold a trade certificate they can make the final connection in fact that is required by law.

[Mary B]

Here the only requirement is having it inspected by a state electrical inspector and that is mainly for insurance reasons.