Transfer Switch

The genset was delivered yesterday. Advice I got from an electrician was that I could use two single pole double throw manual switches to activate my two 200 amp panels. This seems reasonable to me. I don't mind going out to the shop and throwing two switches.

What's wrong with this?
 
There's nothing wrong with using two switches if nothing is switch on, however you can't use two switches to start an three phase electric motor or a machine, because depending on the phase you switch first it will change direction of rotation.
 
Nothing wrong with that so to speak but.....


Back in past life we has many stand by plants as well as portable use sites where trailer unit is plugged in.

Standby were fully automatic where others were manual.

Manual had either a large switch that was panel sized 2 pole 2 position with load as common and line and generator as either or positions of the switch.

Next company used a much cheaper design in that it used a pair or paired interlocking breakers that only allowed one or the other to be selected and these were the main entry breaker for the panel.

The main point here is there are many options but one item is critical in that there must be no possible way under any idiot operating the controls to place the generator to line.

For this size unit do look for and spend to buy certified unit.

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You will need to verify for your area, but here I know a generator transfer switch has to have the same rating as your incoming service since both power sources go through it.
That said, if your incoming 400 amp service splits into two 200 amp service panels, you might get away with using a 200 amp transfer switch for each the individual sub-buses.
From what I remember when I had my standby generator installed, a 200 amp auto transfer switch ran about $1000, but a manual one ran about $400.
That was probably 6-8 years ago so the prices are probably somewhat higher now, but from what I saw I think two 200 amp switches would be cheaper than one 400 amp switch.
If you don't need both sub buses, you could just connect to one of them and only need one transfer switch.
I'd definitely talk to your electric company. They will probably be a better source for information on what would be legal/required.
 
There's nothing wrong with using two switches if nothing is switch on, however you can't use two switches to start an three phase electric motor or a machine, because depending on the phase you switch first it will change direction of rotation.

I get my 3phase from a rotary converter.
 
High amp switches can get expensive. I hate this option but breakers are often used for switches. specially in LOTO.

Do you have a main 200A breaker in each subpanel? Does the Generator have proper current limiters?

Ask your electrician about grounding of the generator how he plans to do bonding.

The more "automatic" you go the more complicated and costly.

I did one job where the generator was backup to a cell/wireless/internet tower. When the power went out [winter storms in Northern CA], we had battery backup and a generator to charge the batteries.

The system would check for power outage and swap over. The smart system send a message so technician that it was down and stamp time for him to get there with more fuel for generator. We found a German device that could trip off of low voltage signals and it would send wireless signal back to software control. Other checks in there as well

Think of a small concrete block room at the bottom of cell tower that is 2 hours from service guy's house on a mountain road. If the tower goes down, the boys playing video games will be off line and ****** off. Important stuff.

Joking aside, this kinda stuff is part of what is needed in those hurricane areas. Not much you can do if the top of the mountain is gone and the tower is n the Bermuda triangle.
 
This is a cell tower takeout. Only has ten hours on it.

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. Hopefully he will get back to me with a price. The unit is only 35' from the service entrance. No digging a trench, can run directly through the carport.

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 have the same exact circumstance but using a 35 kW generator. My normal utillity service is 400A 500 MCM and also splits into two 4/0 feeding 200 A panels with local disconnects. To ease installation and approvals, I opted for a whole house system with the utility meter nippled to a 400 A ABT. This arrangement also eased utility failure takeoff and generator battery trickle charging connections, etc. However, having two 200A disconnects may require more real estate and may possibly cost more than just using a single 400 A ABT.
 
Let us know how it turns out and what you do, knife switches was my 1st thought.

When you turn them off, do a visual check that the blades are disconnected. I've seen a failure on a 3 phase system where one leg was still connected. Tech turned it off for upgrade job. Measuring around it was funky and then we found the failure. I think it was a 225 A service inside a large building. I don't remember where it broke on the lug or hardware.

Measure and visual for me on those.
 
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? they seem well insulated and suited to safely isolate and switch to gen power. can't speak for legal..usually when it's not expensive enough, someone finds a way to stop u...
 
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