200 amp transfer switch (ChangFa Generator project)

My posting didn't have the intent to make "safety first" ridiculous. You are right and I _fully_ agree that every means has to be taken that the generator is not feeding the outside grid. Under no circumstances. Also the way the gen is connected to the house grid has to be done it has to be done. No kidding around. If in doubt, get an electrician, spend money and sleep well.

Nick

Reply to
Nick Müller
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Sounds like some of the cautionary wisdom I used to hear from my grandmother. You know; like the horrible cramp you get if you go in the water

59 minutes after a light lunch, or the hair on the palms...

Often repeated bullshit. Please give us one cite where this has ever happened. It depends on state and local insurance regulation, but generally your home insurance protects you even against your own stupidity. Frankly, if "stupidity" were excluded, there would be little point in having fire insurance.

Again, often repeated bullshit. Please cite one case where someone has gone to jail under the circumstances you describe. Also, the potential fatality is very unlikely to be a lineman, they treat EVERY conductor as hot...they live longer that way.

Again, unlikely. You see, standby generators are typically several orders of magnitude SMALLER than the generators the utilities typically use. A typical homeowner's generator will go up in smoke long before it will backfeed an entire neighborhood.

If "survivalist thoughts" means someone thinking in advance to safeguard family and home from something as predictible as hurricane season, I see nothing wrong with it.

Yes, sometimes "money-saving shortcuts" are a bad idea.

Actually, I fully agree that generators should be connected to house wiring only through approved equipment. In that respect, in fact, that is how mine is connected. I just think that bogus "boogy man" stories are not the way to get that point across.

What is it about then?

Regards, Vaughn

Reply to
Vaughn

Although, in fact much of the "approved equipment" includes stuff like transfer switches that depend on opening one breaker and closing another - with a simple mechanical interlock to prevent both from being closed at the same time.

Those are UL approved transfer switches but they still have the opportunity to have a breaker stick shut and backfeed the incoming line.

Unless one ohmed out the opened-up breakers each time, it could not be a 100% sure thing.

Jim

Reply to
jim rozen

"James Lerch" skrev i en meddelelse news: snipped-for-privacy@news-server.tampabay.rr.com...

Camlock connectors are widely used in the entertainment industry ( and incidentally they look a lot like the connectors used on stickwelders in europe )

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Another option may be CEE form connectors, widely used across europe:
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The biggest ones available is a 5 pin ( 3 phase + neutral + gnd ) 125 amp for a 230/400V setup..

Best thing about the CEE connectors is that they are close to indestructible and pretty much waterproof... ( Wouldnt drop them in a lake tho :-)

/peter

Reply to
Q

The transfer switches that I have seen, have blades that are too small to close both sets of contacts at the same time.

i
Reply to
Ignoramus9053

Interesting, they also look a lot like welding cable connectors used on the Miller Big 40 DIesel welding machines as well.

I'm buying a 200amp transfer switch, I know that much for certain. The question that remains is the simplest way to go from the transfer switch to the generator, while still keeping the generator portable.

But first, I should probably make sure the generator gets finished :)

Take Care, James Lerch

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(My telescope construction, Testing, and Coating site)

Press on: nothing in the world can take the place of perseverance. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent. Calvin Coolidge

Reply to
James Lerch

I would simply use some appropriate terminal blocks, what's the big deal, why the need for pluggable connections. Hurricanes do not happen often.

and load tested...

i

Reply to
Ignoramus9053

I've seen the ones with pairs of breakers on the panel, with a sheet metal toggle link that prevents one from closing before the other is opened. They're not bulletproof, yet they're UL approved.

Jim

Reply to
jim rozen

These, I believe, are called interlock kits and not transfer switches.

i
Reply to
Ignoramus9053

"James Lerch" skrev i en meddelelse news: snipped-for-privacy@news-server.tampabay.rr.com...

CEE forms would be my suggestion... Safe, relatively cheap and definately reliable..

You could just leave a length of SOJ hanging off the transfer switch.. Plug it in the gennie when needed..

Most Euro places ( and probably some american places too ) have CEE forms in the 3 ph + neutral + gnd version available in 125 amp ( per ph@ 230/400V ) models.. They should cost about 50$ each...

The size range is: 16,32,63 and 125 amp 3 phase... Some UK places also stock these in single phase versions..

I dont know anything about electrical codes in the US, but I doubt it would be a problem using something like these in the US ( connectors are rated for twice the voltage and twice the current compared to what you need )

Altho: You might want to consider looking in your neighbours shed to see what kind of outlet he is using... That way you could steal power :-)

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can sell you the camlocks and appropriate cable if you choose that route.. I have not done business with these people personally, but they have an excellent reputation within the entertainment industry..

/peter

Reply to
Q

A 200amp plug is pretty beefy. I took a similar approach, but I did it with a 60amp subpanel instead of the main. The subpanel plugs into a

60amp outlet powered from the main panel, or it plugs into an adjacent outlet powered by a generator.

I also permanently grounded the subpanel, instead of connecting/disconnecting the ground with the plug.

Don't know about that. In my case, I designed it to be easily rewired if at some point that should be desirable. I believe it to be safe and compliant, but I would not be suprised if there were some corner case which prohibits permanent fixtures (the subpanel) from being cord and plug connected to other permanent wiring.

sdb

Reply to
Sylvan Butler

The UL symbol on electrical devices isn't an all-purpose designation. Many UL listed devices are listed/specification specific to be acceptable for a single purpose.

Consumers buying products labeled on the packaging as "surge protectors" were purchasing devices that were UL listed as interconnecting devices.

I believe the UL listed symbol used to represent a level of safety and quality/reliability, when there weren't so many thousands of different electrical devices, for so many specific uses. Examining some of the low quality imported home and commercial lighting products, for example, which have UL labeling, makes me doubt that the UL symbol is a reliable overall representation of quality. The products in the stores may not be of the same quality as the design specifications that were submitted for approval (very poor quality control at the manufacturing level).

There are numerous other international organizations that approve electrical component designs. When I see several international approval symbols on a product, I feel confident that the product is very likely to be reliable.

This gets into an area where the user needs to know what any type of approval labeling is actually intended to represent.

We've all heard mil-spec thrown around casually. There are specifications for all types of products, and without actually knowing what the specific designation actually represents, any particular product may not be suitable for it's (next) intended use.

When someone has a mil-spec ratcheting tie-down, they might not know if the original specification was to tie down aircraft or what other use it was spec'd for. For wire, one should know the insulation breakdown voltage rating and the acceptable limits of the insulation, as an example.

WB ...............

Vaughn

Reply to
Wild Bill

Yes. All that UL and DIN and CA and the like care about is safety, so their tests verify only that the device won't catch fire or electrocute anyone. They do not test if the device is of good quality, or suited for its claimed purpose. Only safety is tested.

That said, a product with multiple symbols usually comes from a large company, simply because it costs lots of money to go through all those tests, and larger companies usually finish the engineering before shipping the product. But not always.

All MIL-SPECs are now available on the internet, so a little googling should tell the tale. If the product claims to be MIL-SPEC, but doesn't give the spec number, ignore the claim and don't buy the product.

The National Electrical Code and UL require that this information be stamped on the wire itself, and verified by certain UL tests. It isn't just a manufacturer claim.

Joe Gwinn

Reply to
Joseph Gwinn

That's probably correct. I guess my point is that there's a large number of people who are purchasing them and installing them because they feel they are an acceptable solution to the problem of installing backup power to their home without the danger of backfeeding the utility line.

But really all they do is close one residential quality breaker while opening another. If the utility side breaker sticks closed then the backfeed will happen. How can utiltities allow such a setup to be sold as an approved device when such a danger exists?

Jim

Reply to
jim rozen

Leviton mfg is actively pursuing legal recourse against several mfgs and importers of sub standard gfci receptacles. I was reading about this the other day. UL is not a big deal to begin with, it just costs money to get something approved. I used to work for a small panel shop and one of the OEM custmoers we did work for required their final product to be approved. This was 15 years ago, and it seems like it was in the neighborhood of 6 thousand bucks for one controller to be approved.

Reply to
Grady

that's not legal in a house...

i

Reply to
Ignoramus28572

There are also some very poorly designed (crap) products produced in the USA.

I've seen wall receptacles installed in new mobile homes that are enough to give ya the creeps. The connection method is IDC (insulation displacement connection), very much like the taps for automotive wiring.

Some folks hate the more common strip/push-in connections (myself included), but the IDC is far worse for conductor contact area. The slot is in a brass tab that's maybe .060" thick.

It would be reasonable to assume that these IDC parts would have some additional protection when installed, but they don't. They don't fit into standard boxes, and aren't intended to be mounted in boxes, since the fastening method is the little arm that swings out as the mounting screw is tightened (capturing the drywall between the arm and the mounting flange (all plastic housing construction, snap together installation to the wiring).

The IDC termination technique has been successfully used in the electronics industry for decades, although the connectors are generally all low voltage and/or low current.

WB ................

specifications

Reply to
Wild Bill

There are two basic types. There is the spring-loaded style (that I don't trust) and there is the type where the connection screw tightens a plate that captures the wire. That second type is pretty good.

(Shudder) I have never seen these things. Have you ever seen a mobile home burn? I thought that they generally improved the mobile home wiring code about the time they outlawed aluminum wire in them? Wrong?

Especially in the telephone world.

Vaughn

Reply to
Vaughn

They are called interlock kits when sold as an add on device for existing breakers.

When used in a manufactured and tested transfer switch arrangement the finished assembly is indeed considered a transfer switch.

The authorities having jurisdiction also feel that they are an acceptable solution.

The probability of any of the breakers in your panel sticking closed is very low and probability of the one specific utility feed breaker sticking closed is extraordinarily low. This is particularly true since those main breakers are generally running far below their ratings, unlike individual branch circuits which operate at 75% load far more frequently.

The utilities do not have any authority to regulate such things.

Pete C.

Reply to
Pete C.

The first type is indeed crap and unreliable. The second type is quite good and generally better than the manual wrap-around-the-screw method, particularly with stranded wire.

While I wouldn't want cheap IDC connectors mounted without boxes in any building I owned, don't automatically write off the IDC connections as crap. The receptacles used in the Wiremold (tm) outlet strips are all IDC and the quality is quite good. I've seen these strips abused to the point where the receptacles are cracked and popping out, but I've not seen the IDC connections fail.

Good IDC connections are gas tight and get more contact area than you would think. The cheap spring contact backwire receptacles are not even remotely close to a decent IDC connection.

The RJxx type phone connectors are one of the cheapest designs around, but they rarely have a connection failure as long as they are applied correctly to begin with. Usually they die from the latch tab being broken. The '66' punch down blocks are decades old and still chugging along. Again with gas tight IDC connections they don't have oxidation problems.

Pete C.

Reply to
Pete C.

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