Questions about CODE UL1741, getting cheap inverters to legally work

Once I stop tweaking the design of the GS inverters, and have carefully examined the UL1741 spec, we fully intend to get the Genetry Solar inverters UL-certified at no additional cost to customers.

Can't speak to the legalities of UL, etc.--obviously, for personal use, it's 100% your risk.  My personal system setup won't pass UL.

You can obviously sell whatever you want, UL cert or not (GS inverters currently are not UL cert).  Not having UL cert simply means that they can't be installed in a commercial/industrial or other setup that requires such certification.  (Legal grid-tie connection obviously is completely out of the question without UL cert.)

Think about it: a Power Jack inverter doesn't stand a chance at passing a UL cert--but it can be sold.  If it isn't certified, you just can't use the logo--and professional installers can't install it.  But DIY homeowners could use it if they chose to.

At least that's how I think it works.  Don't know much about it TBH.

It all depends on where you live really. Some places would come down on you just for having a non-UL listed item to start with. Others won't do a thing as long as you have a transfer switch and don't grid tie the inverter to the grid. In an emergency, such as is going on in Texas right now, the use of emergency power systems that are not grid tied go. In our case after Hurricane Andrew, the power company would not reconnect your home if you had a backup generator running unless you had that transfer switch. As we have two, they had no problems with it. In fact, the lineman was kind of surprised when he saw our main one. It can handle 3 phase (with an extra lug set installed ) at 600 Amps. Most places only look at permanent installations so anything that just plugs in doesn't get looked at. YMMV.

Im am trying to install several small systems for family members and want to do so in legal manner, [they insist] so that is why i was thinking of just connecting it to there existing generator ports, but am trying to confirm if its legal , all these codes are so ambigous, and frustrating, i guess at this im trying to find are they any laws or regulations on what and what not can be connected to a generator port

Methinks that they won't care too much about that after the lights go out...

On 2/16/2021 at 1:58 PM, Sid Genetry Solar said:

Methinks that they won't care too much about that after the lights go out...

So true. If you had seen how some of the people did it after Andrew, you would cringe.  While out with the FDOT crew I was wearing 20KV linesmen's gloves and inserts as I had no idea if one of the idiots was backfeeding a transformer somewhere. And I made sure that the 4' bolt cutters were nowhere near any part of my body while cutting the cables. The DOT crew had a chainsaw with carbide teeth but no protective equipment for Voltages that might be present. Ever see a 4' diameter concrete pole snapped off at the base? The cables on it were about 1.5" diameter and had a steel core. Sad part was they had only been installed a few months before and weren't even in use yet.

I'm sure of that!  I might be a country bumpkin with redneck ideas every now and then, but people sometimes do some really dumb things.

1 hour ago, Sid Genetry Solar said:

I'm sure of that!  I might be a country bumpkin with redneck ideas every now and then, but people sometimes do some really dumb things.

We had a power outage lasting 3 days here in KY. I had to make a suicide cable to get someone's heat back on...

<img class="ipsImage ipsImage_thumbnailed" data-fileid="56" data-ratio="96.55" width="348" alt="suicide-cable.jpg.c64ecdd48e3810818a8e0ce9682cae0f.jpg" data-src="/monthly_2021_02/suicide-cable.jpg.c64ecdd48e3810818a8e0ce9682cae0f.jpg" src="/applications/core/interface/js/spacer.png" />

Of course, I know the risks, what not to do, etc. Alot of janky electrical around here you have to work around.

Yep, that is what a lot of people did down here too. Which is why I said about the power company refusing to restore power to many places unless there was a transfer switch. Most common one I saw was people feeding a Dryer outlet inside the house. At least some of the people were smart enough to pull the main breaker so that there was no danger to linemen working to restore power. Others stupidly just turned the breaker off without a lockout device. I can lockout both of the transfer switches we have.

As far as codes go, they are entirely up to what's known as the Authority Having Jurisdiction, AHJ. That is your local city or county building inspection department. Even if the area doesn't have a requirement for permits or inspections, the state still has a minimum building code that they can punish you for not following if an incident happens and someone dies.

The National Electrical Code deals with the wiring within the building and the electrical devices permanently attached to the structure. The parts used in the construction of the permanent electrical system are UL listed. But once you've accomplished that, the code doesn't say much about how that system is supplied. For example, the code doesn't say anything about how a portable gasoline generator is built. It only cares about how you connect it to the building. The worst Harbor Freight Chinese generator is fine by code, so long as the inlet to the building is proper. But a permanent standby genset bolted to a slab and hardwired will be a UL listed assembly and be under the NEC's authority.

Similarly, an inverter screwed to a wall feeding wiring within the walls of the building would have to be UL listed by code. As would the battery charge controller. But that same inverter in a box on wheels plugged into the building is OK. But the final decision rests on the AHJ. They very well have the authority to accept a non-UL component. In my experience, if a device is well built and of clear quality, they let a lot slide.

I think an inverter manufacturer would dodge a ton of liability by putting a sticker somewhere to the effect of "Not intended for hardwire connections to permanent wiring."

Wow, thanks for the clarification.  I never realized that...now a large commercial project that GS is part of makes a LOT more sense...sounds like we should be making wheeled units with Anderson connectors on 'em 😎

Of course the UL1741 document won't mention loopholes like that.  We still plan to pass the UL1741 test once we get all the development done...but this is good to know.

I use  2 products to connect generators to homes in the area. One costs 800 dollars http://www.generlink.com/ and the other 80 dollars https://www.geninterlock.com/ Our local electric coop will install the 800 dollar one because it stops power feed back automatically. the other is just a mechanical  interlock that keeps the main breaker off if the generator breaker is on. now as far as the legality of them that is up to the local codes.

Phoenix  Arizona city code  and  Arizona utility company   do not allow transfer switch or suicide cord  to be  connected  to  the main panel  even if the  inverter is UL listed .  My powerjack  inverter is directly  wire to the  220v  appliance and heat pump  .   Almost  all inverter  are use in RV  and  have  nothing  to do with the  utility company .  I  think  Arizona  has the worst code  for DIY  installation .  

How do people in Arizona install standby generators if they aren't allowed to use a transfer switch?

Sorry  I   was talking  about  DIY  installation .  People  can install  standby generator  if  they get  city permit cost over 500 dollars  and hire licensed  electrician which is very expensive  to install the transfer switch  and  then  have the utility company  approve  the  installation  .   The  cost  to install  a transfer switch  for a powerjack  inverter  will  be  more than the  cost of inverter  because of the permit  and  hire a  licensed  electrician  .     The  main service panel  is  outside  so it is impossible  to hide the  transfer switch .  Code violation is very  expensive  in Arizona  .     Your  forum  on grounding   is the  correct  way  as all  metal case  should  should be grounded  to avoid   being  electrocuted  .