help selecting a manual transfer switch

I'm trying to find the specifics of the double-throw manual transfer switch I need to run my whole house off my generator.
I'm planning to have a 6000 watt gas generator with a L14-30 type 4-wire output socket in a 3-wire 200 amp house electrical system. I would like the transfer switch indoors.
My question is which kind of double-throw transfer switch do I need?
fusible 2-pole 3-wire w/SN (sn=solid neutral?) fusible 3-pole unfused 3-pole
If I had to guess it'd be "unfused 3-pole" with a breaker panel that has a main breaker and "fusible 3-pole" with a breaker panel that contains breakers only for the branch circuits, whatever is cheaper.
I'm I close?
(I've tried to find relevant text in the my 1996 NEC with no success.)
Secondly, I'd wire the generator up like this:
"G" of L14-30 (chassis ground) to earth ground of my house system "W" of L14-30 to transfer switch neutral "X" of L14-30 to transfer switch hot "Y" of L14-30 to transfer switch other hot
Is this right?
Any help appreciated, wahzoo
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Im not sure on the wiring but Generac has pre wired 6 circut kits with exterior box , socket, interior panel ,amp meters, and exterior cable and plugs for 2-300 a good deal and less headache. At lowes
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Take a look at the Line Transfer Switches that Lowes sells.. I'd be willing to bet that they meet your local codes, in addition to the NEC requirements.
I'm not sure that it is necessary to swith the nuetral but it may be a safety requirement.. When I lived overseas I had a generator and line transfer switch to handle the whole 200 amp load.. I didn't have to switch nuetral..
--
My opinion and experience. FWIW

Steve



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your generator. If non-bonded, you must not switch the neutral. All the generators I have seen have been non-bonded, and all the transfer switches have not switched the neutral; which fortunately go together. An excellent article on it is at: http://www.schneider-electric.ca/www/en/products/stab-lok/Gen_Panels_Appl_Note_EN.pdf
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http://www.schneider-electric.ca/www/en/products/stab-lok/Gen_Panels_Appl_Note_EN.pdf Thanks, that link is the first humanly readable article I've seen on the subject. This refers to the CEC, so all I have to do is verify that the NEC is proposing the same.
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The first question to ask is what loads do you want to run off the generator -- anything in the panel, a handful of circuits, or somewhere in between? I don't like those Gentran transfer switches, and you can get them for up to 12 circuits, but usually only 1 can be a double pole (240V) circuit. These are the most common and probably least expensive solution. They are also typically limited to 15A circuits. The intermediate approach is to put a transfer switch between your main panel and a subpanel. Then run all the circuits you want to run from the generator in the subpanel. Finally, you can put a transfer switch in front of your 200A panel and be able to run any load in your house that is under 6KW, but you'll have to switch things on and off to keep from overloading the generator. You'll also have to mess with Service conductors which will require you to at least pull the power meter and probably run some new conduit.
Transfer switches for option 1 are about $150 to $300. A transfer switch for option 2 is $200, but you also need the subpanel, the feeder cable, and a large breaker to protect the feeder. Option 3 costs $300 plus service conductor rework.
As far as the switch itself, it doesn't need any fuses. But you have to have a circuit breaker somewhere near the generator to protect what is going to the transfer switch, and each branch circuit must have a circuit breaker. A 2-pole switch is the minimum required, and will require you to separate the neutral/chassis bond in the generator if using option 2. A 3-pole switch will work with any configuration and is the preferred switch because you can switch the neutral too, thus eliminating any downstream rebonding of the neutral which isn't allowed. But this creates a Separately Derived System.

They're all legal so you won't find it. The problem is breaking all the other little rules scattered throughout the book depending on what approach you take.

Yes, but the neutral/ground bonding issue needs to be addressed and depends on how you do things whether they should be bonded or not.
You can get a 200A Cutler-Hammer unfused 2-pole manual transfer switch from Harbor Freight Tools for $299. I believe this is your best option if no provisions have been made for a transfer switch. But there may be issues with mounting this beast next to your main disconnect and rerouting the service conductors. They have a smaller 100A unit for $199 that you could put in front of a 100A subpanel, but you'll need to relocate everything you want to power to this subpanel.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumberB163
-- Mark Kent, WA
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Sorry, didn't mention this was all new construction. But I did say I wanted to run my whole house. I share your dislike of the GenTrans type switches.

That's great because I priced a Cutler-Hammer model (DT324FGK) for $3420! What brands are you referring to? The Harbor Freight model you mention for $300 lists for $1695 so that's quite a buy, maybe too good. (?)

A fuse between generator and transfer switch? Could you explain it's function?It's only a 6000-watt generator, if I ask too much of it, what's the harm?
and each branch

Thanks for that detailed reply!
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However you decide to go be sure your transfer panel has watt meters, or else you run a high risk of overloading a generator leg. I have to rebalance my panel , Friday I had an outage I was pulling Max off one leg and 10% off the other. Bad for a generator.
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It just shows you how overpriced a lot of electrical equipment is (or how residential stuff is highly subsidized by other customers). A 200A main panel is $80 at Home Depot with 6 breakers included. Buy the equivalent rated panel from CH without the breakers and it will list for $300. I bought the 100A switch from Harbor Freight and have been happy with it -- its huge and seems very industrial. A co-worker bought the 200A version.

Generally, all conductors must be protected from short circuits. You could argue that the generator can't source enough current to melt the feeder, but I'm unsure if the code allows you to run the output from a generator unfused (I don't think it does). Usually, a generator has built in overcurrent protection anyway. It also requires a disconnect, but the transfer switch may qualify if it is in sight of the generator, and a power cord would also qualify.
If this is new construction, I'd definitely go with the 200A model. It makes the neutral bonding issue so much easier when this is Service Equipment. You can always bond the generator if you need to, but unbonding some can be impossible. Only requirement with this switch is that it must be mounted immediately adjacent to your 200A main breaker box.
-- Mark Kent, WA
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Some panel brands (SquareD) sell interlock kits. Essentially they let you backfeed using a breaker in the 2/4 position. The kit contains a metal lever or plate that doesn't allow the main breaker and the 'generator' breaker to be on at the same time. For this kit to work, you need a panel mounted main breaker. Essentially it creates a two-pole switch.
-- Steve
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I think you just saved me a 'load of bucks. Could I still have a subpanel that would be switched as well?
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You could have a subpanel fed from the main panel, and it would be backfed from the generator as well. Just keep in mind, 6000 watts won't run much.
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That interlock kit sounded good on paper but it's the klugiest looking thing installed. I'm thinking to that I'd like to have a sub panel and have that switched as well so I'm going with the old fashioned transfer switch.
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Once you install the interlock kit anything that is supplied from that panel, including sub panels, can be supplied by the generator connection. The only limitation is the capacity of the generator set itself. -- Tom H
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