Transfer Switch

eBeast seems to have a lot of 2 and 3 pole double throw knife switches. ....I just ordered a 100 amp one.. u might look for a 200 amp one?

I think I'm missing it, but not heard of eBeast. a quick search didn't help.
 
I have been watching this and had some chuckles. I know you have 2 200 amp panels but what is you average connected load in amps? My guess would be on a rough day you might do 40. I would suggest you find out what your minimum, average, and peak loads are and what the durations are. If you supply only the power you really need, you can load shift and get by with much smaller equipment saving much money. If you want to be able to safely transfer maximum loads with an automatic transfer switch and not kill any linemen in the process (which is murder by the way), then get out your checkbook and put the very best money can buy into a safe system.
 
The guidance proposed herein to simply just use "knife switches" introduces several problems:

1. The switches shown here are likely not listed and if they are, not intended for such service. Listed disconnects are often spring-loaded devices to minimize transition time from OFF to ON and ON to OFF, etc to minimize liklihood for arcing, and often employ features such as arc chutes, etc to squelch resulting arcing. I don't know where one would use the shown switches, maybe perhaps to interrupt a bank of solar cells, etc. - but frankly, they look like cheesy. Proper disconnects are governed by UL 98 and this is what you will want to use.

2. You will need a listed enclosure to contain the switches, and the container/switch must be configured such that the switch can be actuated with the enclosure door closed as a means of containing any possible explosion. If located outdoors, the enclosures must meet NEMA 3R (rain tight) and preferably, NEMA 4 or 4X (splashproof/corrosion proof) depending where located.

3. While it may be true that your actual loading may be far short of the 400A utility service provided, such things as complying with the Code (NEC), and the wiring logistics, runs, interface, etc such as to satisfy the AHJ , the power company, as well as make the design practical --will drive your design. For instance, if you do use two typical 200A disconnects (e.g., DPST) with the present house wiring to connnect the generator to the house, you will also need means to disconnect the utility service from the load panels. You can use a DPDT configuration, but to match the 400A design rating of the utility connection, such a switch shall minimally be rated for the larger current - in this case 400A - even if your emergency load demand is only 10A, etc. The simplest design in this case is to feed a common node such as an ABT or even MBT from both the utility and the generator with the transfer device rated for whatever is the larger. A 400 A automatic bus transfer (ABT) can be had new for about $2K. You can likely pick one up a good used one for much less.
 
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I do have main 200 amp breakers in each 200 amp panel and could go that direction but I have been strongly advised against it. If the power company finds out it would be mightily ******.
Finally got an electrician to come out. He agreed that it would be "legal" to use two manual (knife) switches.
I fired up the unit. It is one sweet running machine. Can't wait to get it hooked up and have the power go out.

I know what you mean. When I installed my standby generator (15 kw Briggs with Auto Transfer switch) I remember thinking "I spent $5000 (completely installed and tested) for something I hope I never need", but it sure was nice the first time the power went out and I heard the generator kick on.

Just a couple thoughts here to ask yourself.
I'm guessing your generator has the auto start/stop feature based on its previous use. Using manual transfer switches, I'm not sure what other wiring connections would be required to maintain this feature. Without it during a power outage, you'd first have to go out and start the generator and then go close in the transfer switches. Check, but I think with this type of set-up, you will have to install lock-out switches for your main feeds by your electric company to prevent backfeeding the grid..
Second, this is a diesel driven generator. You'll have to be sure and have plenty of diesel on hand to feed this monster as well as stabilizer it to keep it from going bad. Gas station pumps require power to operate as well and most don't have back-up generators. So running to the local filling station for diesel during a power outage isn't an option
While you may need 40 kw of capacity to run everything, ask yourself what you would really need during an outage. My generator is set up to run on propane and is rated at 1.5 gals/hr at 50% load. Even at idle (no load), engines require fuel to run and, as you said, diesels don't like just sitting at idle. I live in the country so I have a 1,000 gal propane tank for my house and generator. Max fill on the tank is about 80%-85% so completely full it would run my generator for 16 days with a 50% average load running 24 hrs/day.
I did a quick search on your generator and I found a few 36 kw ones listed on eBay with asking price of around $26,000 plus. I don't know what kind of deal you got on it when you purchased it, but if I was in your shoes, I'd try and sell it. Based on these prices, even if you got half ($13,000), you could buy a standby generator with auto transfer switch installed and have money left over. I'd also recommend using natural gas fueled (if you have service) or propane (if not). Natural gas companies only shut off gas in the event of an earth quake or local fire. Propane can be stored on site in large quantities with no need of treatment, stays good forever.

Either way, I know when the power goes out ~10 seconds later, my generator kicks on, runs through a self test (~20 seconds), and then the transfer switch kicks over and the lights come back on. I don't even have to get my butt out of the chair. When power comes back it transfers back, cools down the generator, and shuts itself down.
The only issue I've had is during times when the power "Flickers" (lights go off and on really quick a couple times). The generator senses this as a transfer switch failure and locks out which I have to go out and manually reset.

Good luck with your endeavor.
Oh BTW, when I searched for a generator and switch, this is the place I found with the best prices. https://www.electricgeneratorsdirect.com/power/briggs-and-stratton-generators.html
I didn't buy from them as I decided to go with a Briggs & Stratton generator. The local dealer delivered, installed, set-up, and tested the generator and transfer switch for about $600 more than I could buy them from this place and it was going to be another $150 for residential tailgate delivery or else it would show up on a big truck and I would be responsible to unload it.
 
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I would be scared to buy and use one of those. Refer to the points blackjack made so well.

I see an arch blast potential coming off of that if switched under load and the person is hanging right next to it on that handle.


My hands on guys would have full PPE setups and never stand in front of the switch enclosure with door open.

Per that companies policies, they would go to electrical safety courses annually and see these types of videos as part of the package. Puts the fear of electricity into you.

Nice thread BTW and great comments.
 
Very good read on an important subject! I would pay to dispose of those Chinese disconnects if I had them. Those are death waiting to happen even with an experienced tech operating them. I'm just looking forward to the part of this story where the commercial grade underground fuel tank gets installed!
 
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