Plug-in Grid tie inverter

[eman21401]

If you are a master electrician then you know why the NEC will not approve that junk. If you don't believe in electrical equipment that connects to the power grid needing to be UL listed then you can't be a true master electrician for the US.

So please stop being a fool and either hang around to learn or take a hike back to your basement.

Dear Sun Eagle, Thanks for your comment. I have already stated my opinion why the NEC and Underwriters has not approved these devices yet. I hope that when they convene again, they will address this issue. I do recommend, however, that they be installed on a dedicated circuit .

[eman21401]

In researching grid tie inverters, I've run across models that plug directly into 120v AC wall outlets. This begs the question: for a grid tie solar system for the purpose of powering a home and selling power back to the grid, can you have a setup as simple as: Solar Array > DC Disconnect > Grid Tie Inverter > Wall Outlet ? (Granted, it would need to be low-wattage since it would be going through the normal wiring and not heavy-duty hard-wired to the main power box)

[ATTACH=CONFIG]3803[/ATTACH]

Hello, I really like these devices. However, I believe a qualified electrician and a dedicated circuit should be used. I also believe the NEC will eventually approve them, but for now, big business and politics is preventing that. I am a Master Electrician in MD.

[ButchDeal]

mike, if you would like to talk about these devices intelligently, please let me know. as far as safety, back-feeding or overloading any circuits, if you plug them into a dedicated circuit, any potential problems are eliminated. like i told you, i am a master electrician in MD and am fully qualified to comment on these devices.

I find it strange that any "master electrician" would recomend installing anything that :

• Is illegal
• does not meet UL or NEC
• can get the homeowner fined
• Can get the service turned off
• can easily be plugged into a different circuit endangering the occupants

I also find it strange that supposed "master electrician" would resurrect a 3 year old thread to state how much he likes the illegal item

[ButchDeal]

Hello, I really like these devices. However, I believe a qualified electrician and a dedicated circuit should be used.

Why exactly do you like a plug in device if you feel that a qualified electrician should install it?
I don't really understand the point of having a plug in device but requiring a qualified electrician to come plug it in. Also the dedicated circuit sure, sounds good till someone plugs it into another circuit.
So if there is a qualified electrician installing it WHY not just install a certified, UL listed, NEC approved wired in inverter?

Also many interconnect agreements don't like unbalanced 120V inverters on only half of the single phase.

[SunEagle]

mike, if you would like to talk about these devices intelligently, please let me know. as far as safety, back-feeding or overloading any circuits, if you plug them into a dedicated circuit, any potential problems are eliminated. like i told you, i am a master electrician in MD and am fully qualified to comment on these devices.

I am sorry but you are incorrect. Back-feeding a receptacle is a dangerous way to connect a "grid tie" inverter.

Now if that inverter was 'hard wired" to a dedicated circuit breaker or if a special receptacle or "connection point" was the only wiring device connected to the circuit breaker and it met the required UL listing I would say it could be done. Doing anything else opens you to losing any insurance claims if that system fails and causes damage.

[jflorey2]

as far as safety, back-feeding or overloading any circuits, if you plug them into a dedicated circuit, any potential problems are eliminated. like i told you,

If it can be unplugged it will be, and will be used on other circuits. (Which is why you put plugs on devices.) In fact, homeowners have demonstrated a perverse sort of ingenuity that they employ to get around problems; any electrician will have half a dozen stories of the horrors they have seen when debugging homeowner electrical problems.

For example, let's say a homeowner has an air conditioner and a hairdryer that are both plugged into the same powerstrip in their bedroom. Works OK for a while. But then it gets hot out and the A/C is running full blast - and the breaker trips when they use both. This annoys them. But then they think - hey! I have that solar power thing that gives me power. I'll move it over here and plug it into the power strip, and it will help out the A/C when it needs a little extra power.

So they do, and it works well. They pat themselves on the back for their ingenuity. And now they have a15A rated circuit carrying 25 amps.

How do you avoid that? Hardwire the inverter.

[max2k]

mike, if you would like to talk about these devices intelligently, please let me know. as far as safety, back-feeding or overloading any circuits, if you plug them into a dedicated circuit, any potential problems are eliminated. like i told you, i am a master electrician in MD and am fully qualified to comment on these devices.

can you then comment on post #8 where danger of these devices was presented? When there's no breaker between any source and the loads bad things happen.

[max2k]

there's fundamental safety flaw in these devices- a plug is made a power source contrary to widespread belief it belongs to a power consuming device. I was badly shocked once (220V AC) from such plug when someone came up with bright idea to make it source being simply out of necessary connectors: the plug was on a desk among others, I took it in my hand and was immediately shocked. Luckily I was able to let plug go as there was nobody around at the time to turn off the power. I wish all these 'inventors' get into their own traps once in a while.

I understand these devices might turn off output immediately after they get unplugged but still making power source ending with a plug is a terrible idea.

[eman21401]

If it can be unplugged it will be, and will be used on other circuits. (Which is why you put plugs on devices.) In fact, homeowners have demonstrated a perverse sort of ingenuity that they employ to get around problems; any electrician will have half a dozen stories of the horrors they have seen when debugging homeowner electrical problems.

For example, let's say a homeowner has an air conditioner and a hairdryer that are both plugged into the same powerstrip in their bedroom. Works OK for a while. But then it gets hot out and the A/C is running full blast - and the breaker trips when they use both. This annoys them. But then they think - hey! I have that solar power thing that gives me power. I'll move it over here and plug it into the power strip, and it will help out the A/C when it needs a little extra power.

So they do, and it works well. They pat themselves on the back for their ingenuity. And now they have a15A rated circuit carrying 25 amps.

How do you avoid that? Hardwire the inverter.

Thank You for you well thought out Example. I am aware this type of stupid installation could happen. I guess the answer, to help them get UL listed, is to make them hardwired. That should help. Still, when your dealing with solar panels, usually the person knows what they are doing. By comparison, the example you provided, this kind of abuse could be done with a simple Space Heater. Why is this Clean Energy Device treated so differently ?

[SunEagle]

Thank You for you well thought out Example. I am aware this type of stupid installation could happen. I guess the answer, to help them get UL listed, is to make them hardwired. That should help. Still, when your dealing with solar panels, usually the person knows what they are doing. By comparison, the example you provided, this kind of abuse could be done with a simple Space Heater. Why is this Clean Energy Device treated so differently ?

Actually if you read a lot of the postings from the people that come here to ask questions you quickly find out that they have little to no experience with solar technology. And some that think they have electrical circuit experience soon learn that DC can be a little different then a low voltage AC circuit.

When it comes to electricity someone getting hurt or worse is usually the end product of being complacent. At least that is based on my 40 + years of experience in the electrical power industry.

[AzRoute66]

[...], this kind of abuse could be done with a simple Space Heater. Why is this Clean Energy Device treated so differently ?

Because one is a power source, the other is a power sink.

[ButchDeal]

By comparison, the example you provided, this kind of abuse could be done with a simple Space Heater. Why is this Clean Energy Device treated so differently ?

Are you kidding? And exactly which Mickey Mouse school did you get your master electricians license from?

[jflorey2]

Thank You for you well thought out Example. I am aware this type of stupid installation could happen. I guess the answer, to help them get UL listed, is to make them hardwired. That should help.

Yes, and once you have bit the bullet and decided to hardwire, 240VAC is a lot cheaper/easier (less copper, better transformer balance.)

Still, when your dealing with solar panels, usually the person knows what they are doing.

Read some of the posts on this forum, and your view on that may change a bit.

By comparison, the example you provided, this kind of abuse could be done with a simple Space Heater.

No, it can't - the breaker will blow before you exceed the wire's rating.

[DrLumen]

Supposedly, the idea of the plug is to make it easy to install. By the time you run a dedicated circuit for a receptacle, why continue to try to use the plug?

[azdave]

Supposedly, the idea of the plug is to make it easy to install. By the time you run a dedicated circuit for a receptacle, why continue to try to use the plug?

Get real. No one buying these things is going to install a dedicated circuit. The device is marketed to people who will completely disregard any install directions and plug it into the nearest outlet. The manufacturers/sellers know this 100% and don't care.