Interesting dilemma (one for the sparkies who hang out here)

[MAC702]

...He pointed me to Art. 455 in the 2005 NEC. Anyone able to look that up for me? I won't be able to get to the library today.

As for the other receptacles, he said those can't be rated for more than the wiring or the overload device - so my using a 6-50 on my air compressor isn't allowed by code when I have the breaker smaller than the 10ga wiring can handle for it. That seems stupid to me.

I'm writing this offline and it'll be four to eight hours before I can post it, so if anything gets duplicated by someone who can get here first, so be it.

First, he's wrong about the receptacles not being allowed to be rated for more than the wiring/breakers. After all, a welding machine that draws 19.5A still comes with a 50A plug, and you can run it from #12 wire and a 30A breaker. BUT, there may be local codes which he might be enforcing. But some people worry about a future danger than someone might see a 50A receptacle and put it a 50A breaker without checking the amapcity of the wires in between. All you can do is ask him for a Code reference, but do so very politely and stay on his good side.

Article 455 is all about phase converters. Skimming through it, I see a few things worth noting to your specific application, but I accept no liability if I overlooked something, of course:

455.6 (B) says the manufactured phase shall be consistantly marked in all accessible locations.

455.8 says you have to have an all-pole disconnect within sight of the phase converter.

455.10 says to follow the table in 430.12 (Motors) for sizing the terminal housing of the phase converter.

[MAC702]

...Also, in calling one of the rotary phase converter outfits, they said none of the commercially available converters are actually UL listed - but that they just use UL listed parts. So how do I get around that? I can't even buy a converter that meets that stipulation of my inspector. He specifically said I couldn't have an idler motor wired up. You need three phase to run a VFD that's over 3hp too, otherwise you need something like 170% of the load rating to run them off single.

The NEC specifies when something must be a Listed component. And it usually says that the thing must meet the NEC or be Listed. If your phase converter meets the requirements of NEC 455 than it does not need to be Listed.

[Fishy Jim]

Am I right in my understanding that a plug and socket constitutes a proper all pole disconnect?

The cords both leading into and from the phase converter will be under 3' long. It will not be hard wired into the structure, but rather "plugged in" just like a genset.

[MAC702]

Am I right in my understanding that a plug and socket constitutes a proper all pole disconnect?

The cords both leading into and from the phase converter will be under 3' long. It will not be hard wired into the structure, but rather "plugged in" just like a genset.

I would think so.

[hankj]

Hiya, Jim. Long time.

I agree with Mac. It's your act, and it sounds like a no-brainer to me. If the phase converter is gone, and the remaining stuff is dead, what's the problem?

If you plan to close up the walls, you might consider running a single-phase feed from the box closest to the panel and leaving it tagged and curled up in the panel for the next guy. It shouldn't be a concern to the inspector. I'd just tag it "future" and bury it in there.

Your inspector ain't the sharpest knife in the drawer. The references to Art. 455 would be pertinent if you were making a permanent install of a phase converter. All you are going to have in the end is a cord and plug connected appliance! Essentially, the downstream wiring is just a fancy extension cord!

Also, his statements about device ampacity vs. circuit ampacity are wrong, as Mac pointed out.

Hope it works out for ya.

Take care, Bud.

Hank

[Fishy Jim]

I finally tracked down the Raco 811c covers today, so I'll be doing the install of the new sockets this afternoon.

I know the inspector ain't the brightest. I agree with you completely about the 10-3 install being a fancy extension cord, and I just don't want to tick him off and have him make me open every friggen outlet box checking for "issues." This guy normally does the most cursory inspection possible and asks a couple questions about how things were connected, then signs off and goes away. The problem, is if he sees something "odd" he gets really interested in it. I have a feeling, had I not specifically asked him about the network of outlets, he probably wouldn't have even noticed that they're not connected to the panel.

I already got the phone co to give me 50' of 6 line exterior cable so I could bury that in the wall - I hadn't thought about adding the wire so the other outlets could be retrofitted down the road. Good idea!

[N20Silverado]

I already got the phone co to give me 50' of 6 line exterior cable so I could bury that in the wall - I hadn't thought about adding the wire so the other outlets could be retrofitted down the road. Good idea!

Jim,

What are going to use the phone cable for???


Tim

[Fishy Jim]

We only have a single line coming into the house right now. When I relocated the main power inlet to the house, I also relocated where the phone line comes in as well.

Rather than having the phone box on the outside of the addition, I mounted it right below the main panel. The tech they sent out was only for DSL, but he gave me the wire so I could run it before sealing the wall up. We don't need more lines yet, so I'm not going to have them connect the new one until we do.

[N20Silverado]

We only have a single line coming into the house right now. When I relocated the main power inlet to the house, I also relocated where the phone line comes in as well.

Rather than having the phone box on the outside of the addition, I mounted it right below the main panel. The tech they sent out was only for DSL, but he gave me the wire so I could run it before sealing the wall up. We don't need more lines yet, so I'm not going to have them connect the new one until we do.

Cool, from your last post it sounded like you were going to use it for your "future" wire from the panel to your first 3 phase outlet.

[Fishy Jim]

lol Nope. I don't think that would handle 30A all that well.

[SignWave]

burying the dead...

Hi Jim,
Ive read the posts, saw the disagreements and comments,and this is what I understand from what you have and others have siad:

You have a phase converter that you wnat to install... How many HP is it?

you intend to put all the wiring from this converter into the walls and button it up? yes ?

you want to use plugs other than twisties for three phase outlets. ( i know, its too late)

Im my neck of the woods, which is canada eh? putting circuits that are not connected to any sort of load or source into the walls is illegal. It boils down to a simple fact concerning safety and common sence. it may be considered abandoned wiring and must be removed to "make it safe"
I would suggest that you mount your 3Φ in surface pipe. That way when you're ready to leave you can "take it with you..." As well, you wont raise any alarms.. you can wire your shop with the regular service of 120/240 and get a pass then once the city dude has come through you can add the rest. This may be more labour intensive, but from my POV its a far better installation in the long run..

just a suggestion. That is how I intend to do my place. Just make sure you size your idler motor breaker and wire size accordingly.

Check out American Rotary. These guys have a UL listing for their machines.
I recently bought a 25Hp unit for 1800 bucks all in. And thats to Canada when the dollar was under a buck US.

Check out http://www.americanrotary.com/

I know that the code for Canada is most likely different than the US code, but essentially they should be the same.

I hope some of this bs helps somehow..

regards Rich.

[Fishy Jim]

Well, we don't have the abandoned wiring thing. When I go, someone else can make this a 230v circuit with little difficulty (or I might get to, to recover my outlets).

I did end up buying twist lock 30A 3ph plugs and outlets.

All the 3ph wiring is 10-3nm (w/ground) and that is more than sufficient for the 7.5hp of my lathe. It is already run in the shop and I have no desire to have surface conduit anywhere in that building.

At any point on any wall, with the exception of the corner where the sliding doors will reside in their open position, you are never more than 4ft from a 120v outlet. All of my double gang outlets are wired with double circuits, so 20A 230v can be derived from them if needed down the road.

I have no concerns about passing the inspection now. Since I know what the inspector expects for the 3ph, and have met those demands, I'm certain that it will be a very quick and painless inspection. The thing that bugs me is not being able to install the sheetrock for the ceiling and get the insulation blown in - till that happens, I can't run my heater with any efficiency and it's starting to get chilly at night.

Also, I called American and they do not have a rating for their device, but that all the components have ratings. A 10hp converter would only be a few hundred more than a new motor if I needed to increase my idler - so I checked into that route and was disappointed that I couldn't spend the easy money and get the inspector's wish granted. If it still doesn't make him happy, that's 400 I would rather spend on finishing the shop.

[Fishy Jim]

Just passed my inspection with flying colors.

Thanks for the input from those who helped.

[storts]

Oh Boy

Sorry for so late,But was playing around and ended here,,
I had CL&P ct. light and Power,,or Northeast Utilities,as I plan on doing a 400 amp service change,all legal,as a home owners permit.

When the big wig from NU was here he spotted my 3 pahse converter in my shop,Garage,,and he was a pretty nice guy,told me when the Union guys get here to cut the power for the change over,,To put a BIG blanket as he never saw the converter,,As he explained to me,it was illegal to "Make my own power" His exact words!

As I explained to him,i was paying for it,not srealing it,and thay sell them,He also said that walmart sold cherry bomb mufflers,But there against the Law,,So he was decent to me,and Polite,I said i would take care of it when the time comes,well its ALMOST here,Any one,specially my Budddy Hank,ever here of this?????????I cant get 3 phase,,they dont even have it on the road!

Any comments would be interesting,Thanks

Jim,In my old dungon,i had ever machine ,came into a disconnect Pipe and Wire,,and out of the bottom of my disconect fused box,i had a offset,with a bottom down facing plug,wish i had a pic,,So my 3 phase plugs wernt sticking out!!!!!!!!!!!I cound stand the couple i had,But had no choise,,Hope i explaided the plug thing,and they were all twist locks! Wish i could draw better,But i think Hank can desipher what Im talking about!!

As for home owners,id have the inspector sign off!!!!!!!!!God nows how ins co's love our money,But if they can find a excuse to PAY! Thats why they hire guys on commish to beat up the person!,Thanks,Jack

[spotsineyes]

I'll post an interesting comment: That guy must be high! Either that, or his sense of humor went over your head. If what he said were true, then your doorbell would be illegal, because you are "making" your own 16 volt electricity with the transformer inside. Or I hope he doesn't find out about your furnace, it has a transformer that is "making" its own 24 volts. I think that the worst thing would be the transformer for your yard lights that "makes" its own 12 volts, and illegally distributes it with your own power grid!