200 amp transfer switch (ChangFa Generator project)

Greetings Gents,

Just got back from Home Despot with a pile of goodies to build my electrical distribution panel for the ChangFa generator (pictures will be forth coming...)

While the main purpose for the generator is mobil power for remote job sites, I also want to run the house off of it when the inevitable happens. Towards that goal, I am looking for a 200amp 240V manual transfer switch to go between the utility meter and my exterior 200amp electrical panel. Seems simple enough, but have you seen the prices of these things?? Grainger wants $499 for a simple manual transfer switch. Even Harbour Fright wants $340 buck for a Cutler-Hammer model..

Anyone have any other ideas on an inexpensive and simple transfer switch?

Currently I'm watching Ebay, but who know's what you get there.

I now see the attraction of the evil method of pulling the electric meter or flipping off the main breaker, and hard wiring in a generator.. (And yes, I understand all the reasons why this is a terrible and dangerous thing to do!)

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
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"James Lerch" wrote: (clip) Anyone have any other ideas on an inexpensive and simple transfer switch? (clip) ^^^^^^^^^^^^^ You may be finding switches that are rated to switch 200 amps under load. You don't need that. You need a switch that will carry 200 amps.

The way I initially built my transfer system was with cable plugs. I wired the house to the meter through a length of flexible cable that had a heavy twistlock plug in the middle. I attached a similar cable to the generator with a matching plug. In the event of a power failure, I unplugged from the meter and plugged into the generator (with a flashlight in my armpit.) This accomplishes the purpose, and absolutely prevents cross feeding between the generator and the utility lines.

Reply to
Leo Lichtman

Northern tool sent a catalog today with those things..manual switch for

100 A is $ 129 with fancier units higher. Look around to see what they've got. they might just have something cheap that will do the job. northerntool.com

Koz

Reply to
Koz

There is a cheaper way if you are willing to pick 8 of your Home's circuits to connect to your generator. Home Depot carries a $120.00, 60 amp generator panel. It has a mechanical interlock so the panel can only be powered from one source at a time.

Store SKU # 311215 Internet # 162355 Catalog # 100096290

Vaughn

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Reply to
Vaughn

Where o where did you find 200amp capable twist lock plugs? I kind of like the idea, as long as code enforcment is happy with it as well... 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 saw those, but I've got 15kw of power (well... I should have 15Kw of power), so I'd like to be able to use it... I don't expect to be able to run ALL my 220vac appliances at once, but it would be nice to run each one individually if the power is out for extended periods...

Hacking apart a new 200amp meter base, and building a simple double pole - double throw switch is starting to look attractive.... I wonder how doable that might be, and if it would pass code when its done.

Take Care, James Lerch

formatting link
(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

Don't bother, it won't

Reply to
Jim Stewart

I looked... and looked... on ebay, all websites, military surplus sales... there is no better deal than the Harbor Freight switch, if you want a whole house transfer switch.

15 kW is only 75 amps. You may be able to backfeed it through a breaker on the panel, and install a mechanical interlock kit that would prevent both the main switch and the backfeeding breaker from being closed at the same time. Check out interlockkit.com. i
Reply to
Ignoramus4093

Interesting, I saw some similar (But much smaller setup at Home Despot). I wonder if I build the interlock myself, it will still pass code inspection?

I have room in my existing breaker box....

Definitely something to consider (either the Kit, or the DIY version).

To be honest, if the generator was one site, and the power went out for several hours / days, interlock or no interlock, I'd have power in my house... :0 Of course, if the damn thing caught on fire and burned my house to the ground, I wonder what insurance would have to say?

In any event, the interlock kit looks promising, I mean it's just sheet metal work.....

Take Care, James Lerch

formatting link
(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

Many switches will carry many times their rated load as long as you don't open it under load. I 'sucessfully' used a 15 amp DPDT switch in a magnet circuit that used 50 apms at full load, worked great since I needed to reverse polarity at essentially zero current. Put up a big sign warning to NEVER flip the switch unless the power supply was OFF. Worked great until some fool flipped the switch at full power to see what would happen; It exploded like a hand grenade.

Reply to
Nick Hull

I am not sure. I am not even sure if the mechanical interlock kit from that website would pass inspection. It would be worthwhile to ask the inspector in your town. My understanding is that at least an "official" interlock kit should satisfy the requirements of NEC. But it is worth exactly what you paid for it.

Kirk Key (kirkkey.com) sells their interlock locks that have only one key that can only be used to have no more than one breaker open, but they are kinda expensive. I called them a few days ago, their locks start at $90 each.

Yep. I will try making something DIY when I have more time.

If you have the main breaker turned off, you would be safe. Maybe tape it over so that no clueless person could turn it back on. Not the best solution, but if an outage catches you before you finish the work on the switch, you need to do something.

Yep... I also want to make my own. Unfortunately, I sold my mill, but I should be able to get by without a mill.

i

Reply to
Ignoramus23758

If you burn down your house, start looking for a homeless shelter. Your insurance agent probably won't even offer you a ride.

If you don't have a fire, but your generator power goes out on the grid/system and maims or kills a utility worker or neighbor, housing will be provided for you.

When the generator power reaches the utility tranformer, it will probably step up to the next level. Now it's not just two 120VAC lines.

Nuttin against you personally, but when these survivalist thoughts are combined with money-saving shortcuts, the chances of hazardous situations rise sharply.

Just so you know, it's not only about your own possible losses.

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

Snippage

Reply to
Wild Bill

"Wild Bill" wrote: (clip) When the generator power reaches the utility tranformer, it will probably step up to the next level. Now it's not just two 120VAC lines.(clip) ^^^^^^^^^^^^^^^ I'm NOT saying you should do it, but the above scenatio is EXTREMELY unlikely. If you tried running your generator while still connected to the utility line, you would be trying to fire up all your neighbors circuits. Your poor little generator's breaker would trip.

There are weird circumstances in which you could harm a line worker, though, so it is prohibited and inadvisable. Your main concern, in taking shortcuts, is to avoid giving your insurance examiner something negative to write in his report. That's how he earns his living, you know.

Reply to
Leo Lichtman

Another realistic possibility is that when the power is restored, the generator's windings will burn due to collision between out of phase utility power and generator.

Surey, doing things in a safe manner is the best route to take.

i
Reply to
Ignoramus23758

And this ain't all! The current will find it's way right into the very next nuclear power plant. There, it will make the steam that drives the generator make _freeze_. from that moment on, only 83 seconds are left and the power plant will have a core melt. But not enough, the extra power of the diesel-generator (in the meantime it will have spunn up to about 370.000 RPM) will go _directly_ into the atmosphere and cause severe hail-storms, tornados, huricanes, snow, rain, dryness, flashes, darkness, sodom and gamorra, earthquakes, tsunamis, ...

Get real!

Nick

Reply to
Nick Müller

I'm sure your concerns would be welcomed by our NFPA. We can start using the wiring codes and safety literature for an alternate fuel.

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

Reply to
Wild Bill

Here in the US, country folk often have their own distibution transformer for their property, connected to possibly miles of 7kv - 13Kv distribution lines. A break in the distribution line, followed by a customer back-feeding 120/240 into his transformer can indeed cause a very hazardous situation for a lineman.

Reply to
Jim Stewart

I do not think that anyone proposed to backfeed the incoming electricity line in this thread.

i
Reply to
Ignoramus23758

OK, that's an argument. But I bet the ground _both_ sides of _any_ power line they work on.

Nick

Reply to
Nick Müller

The term for the expression "that'll probably never happen" is Tombstone Mentality.

The safety codes are a system of approved fail-safe interlocks that are intended to absolutely prevent the possibility of the "probably won't" scenario.

I'm no expert in any field. I've worked in hazardous locations, sometimes with other people that I didn't want there. I can't say I've developed a keen sense about what could happen, but I usually consider possibilities before I start.

A friend that was a supervisor for our local power company told me that historically, significantly more deaths happen from folks messing around with their home wiring than utility workers that are working near the even more hazards equipment every day.

Just before he retired, he was responsible for monitoring a specialized out-of-state subcontractor that was replacing splices on hot lines (according to him) at the tower tops, the ones that go across several counties. I saw the crew in action a couple of times. I had to wonder where all the static went.

They were working from a platform attached to the side of a helicopter. Attach a tensioning device to hold up the wire that spanned two towers, remove the old splice, install a new one. This type of system maintenance would eliminate larger expenses later, out-of-court settlements and large area outages.

OTOH, there are those that never have enough time to do the job right, but can manage to find time to do it over, when it fails. Advice for them is to buy their next house before they start to fix up their present one.

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

Reply to
Wild Bill

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