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Generator Interlock Listing question.

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AA/FC

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Hi guys, I purchased this generator Interlock a few weeks ago and I want to get a permit from my city before I install this. However, I want to make sure this device is legal before I buy a permit and install it but I can NOT get anyone from the city to reply to my question. I've tried emails, phone calls, voice mails.... they don't reply. I can buy a permit from my city on their website. In fact, all permits from this city are now purchased through their website so it's not like I can ask questions when I'm at city hall buying a permit in person.

Anyway, my question: The way I understand it is.... A generator interlock is legal (in the NEC) as long as it's "listed". Am I correct in assuming that it can be "listed" by any OSHA Nationally Recognized Testing Laboratory? And it appears to me that "MET" is an OSHA NRTL, correct?

So, is this Interlock NEC legal? I want to buy a permit as soon as I find out if this device is indeed NEC legal.

Thanks in advance.

Generator Interlock.jpg
 
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dcg9381

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I think this is one where I'd install it and not ask questions up front.

I've been buying interlocks from (interlockkit.com) - they appear to be doing them for major product lines, but they'll also do custom.
I can't find anything that says they are UL listed. Custom can't be UL listed.

My understanding is that NEC 702 covers this, but may have "interpretation" holes.

IE - "Transfer equipment is not defined in the NEC. It is totally up to the AHJ as far as accepting interlock kits as transfer equipment for an Article 702 installations."

I believe (at least older NEC) had 702.5: "suitable for the intended use" and it "prevents inadvertent interconnection" - good enough for me. Maybe not good enough for your inspector.

Some smart sparkie will find holes that could be used to say non-UL interlocks are non-compliant... But the way these things work is pretty mechanical only.
 
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dcg9381 said:
I think this is one where I'd install it and not ask questions up front.

I've been buying interlocks from (interlockkit.com) - they appear to be doing them for major product lines, but they'll also do custom.
I can't find anything that says they are UL listed. Custom can't be UL listed.

My understanding is that NEC 702 covers this, but may have "interpretation" holes.

IE - "Transfer equipment is not defined in the NEC. It is totally up to the AHJ as far as accepting interlock kits as transfer equipment for an Article 702 installations."

I believe (at least older NEC) had 702.5: "suitable for the intended use" and it "prevents inadvertent interconnection" - good enough for me. Maybe not good enough for your inspector.

Some smart sparkie will find holes that could be used to say non-UL interlocks are non-compliant... But the way these things work is pretty mechanical only.
Click to expand...
I was on the fence about pulling a permit but I eventually decided that I want this to be done correctly. (legally) I asked a journeyman electrician friend of mine here locally if interlock devices were legal around this area and all he said was "yes, as long as they are listed".

Anyway... an update to this thread:
I went on-line and applied for an electrical permit with my city. I attached the same picture above to my permit application to show them exactly what I want to install. We'll see if they approve my permit. It says it could take up to 10 days to get approved. I should've applied weeks ago when I started collecting parts for this project. lolol.

Thanks, dcg9381 for the reply!
 
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dcg9381

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Sure.. The one thing I've run into outside my normal ETJ working with a master electrician is that he said to do an interlock the ETJ was going to want a load calculation. Which would be fine, but a 30A or 50A interlock supports a very limited KW generator, in many cases perhaps not enough to handle the load. He said he'd "do it anyway" (I assume because the ETJ won't make a stink) - I'll let you know if we have an issue with it.
 
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dcg9381 said:
Sure.. The one thing I've run into outside my normal ETJ working with a master electrician is that he said to do an interlock the ETJ was going to want a load calculation. Which would be fine, but a 30A or 50A interlock supports a very limited KW generator, in many cases perhaps not enough to handle the load. He said he'd "do it anyway" (I assume because the ETJ won't make a stink) - I'll let you know if we have an issue with it.
Click to expand...
What is an ETJ?
 
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wyliesdiesels said:
yes it needs to be listed and label for use in the make and model panel you have

since you didnt tell us that info we cant tell you if its the correct interlock
Click to expand...
It's a siemans 100 amp panel. Yes, it is the correct interlock device for my panel, I was just wondering if the MET listing would be good enough to satisfy the inspector.

Another thread update: The city just notified me that I could log-on and pay for the permit, which I did..... Then shortly after that I get another email with a printable PDF file that contained my issued electrical permit. Wow, that was quick.

I included a picture (the same picture as posted above) with my electrical application, along with the description of the job which said.... "I plan to add a power inlet box onto the back of my house, along with a generator interlock device installed on the cover of my main panel". I have to imagine that someone with NEC knowledge approved my permit, and not just the office secretary. lol. I can't imaging they would fail me now for not having the correct interlock when I sent them a high res picture on my application. lol. We'll see I guess.

Thanks to everyone who has replied. I will keep this thread updated to let everyone know how this deal goes for me.
 
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Ironically the inspector just returned my phone call a few minutes ago.... he didn't even know that I purchased a permit earlier today. I asked him about the interlock device and then I told him how I plan to do the project and he said everything sounds great, and I shouldn't have any problems. That was nice to hear from the actual guy who will be inspecting my project. Thanks again, guys.
 
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I just wanted to put a period on this thread in case someone in the future has the same question that I had.

I installed the new generator interlock device on my panel, along with a 30amp generator inlet box on the back wall of my house.

The city inspector came out today to inspect my installation..... Not only did the generator interlock device pictured above easily pass inspection, the inspector also complimented me several times on the quality of my work. (which was nice to hear)

So now I have an officially inspected (and passed) generator interlock device with inlet box installed on my house that shouldn't cause any trouble in the future with either selling the house, or with he power company thinking that I might be illegally back feeding. Everything is legit so there should be no questions later.

Thanks to everyone who took the time to reply to my thread above.
 
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