Power transfer switch for generator
 

I have a 7500w running/ 9375w start up, 30 amp 240v portable generator and want a power transfer switch. I don't want one that powers only certain circuits as I'm supplying power to two panels, house and shop.
I know not to overload, I have no problem flipping off breakers to circuits I don't need.

I need power to shop direct vent furnace, two small fans on my house gas fireplaces, 3 sump pumps, well pump, some lights.
AC, water heater, etc., I would turn off.
A manual switch is fine. Heat and cooking is all propane.

I want feedback safety, plug in outside receptacle, load meters would be nice and do these tell you when the power comes back on?

This below is what I want it to do, but it's expensive and the meter sticks too far, it would be a headbang hazzard.
https://www.homedepot.com/p/GenerLink-30-Amp-Meter-Mounted-Transfer-Switch-MA23-N/301961623

Any suggestions on a parts needed list?
Thanks

I am thinking the transfer switch you are choosing will still activate the wattmeter and hydro will charge you for the power you are supplying to yourself with your own generator because it is before the meter. that would be a deal breaker for me.

Joel, That's a good idea. I backfeed, as I have only had to do it twice in 20 years.

Mark, around here the utility company would balk about a device attached to their meter, and would require permits and a new service inspection.....

Shop is on a subpanel? Why can't you treat that as one of the circuits with a conventional transfer switch?

Or are both panels (house and shop) subpanels with a small load center between them and the meter?

If so, I believe you could use something like this whole house transfer switch (link has a link to the spec sheet): http://www.generac.com/all-products/transfer-switches/portable

House main panel is 200A, shop subpanel is 100A.

I could just backfeed it through my welder plug, but I have no way of knowing when my power comes back on. I also want to make a simple plug in/switch and teach my wife how to hook up the generator just in case.

I'm also thinking long term I'd like to install an outside cabinet with a pad to store the generator, so it doesn't need to be moved into position. The generator is electric start so I'll have to wire an outlet for a battery trickle charger.

So I guess this, an inlet plus extension cord is the cheapest route.
I get what it does, backfeeds through a 30 amp double breaker and the plate slides so only the mains or generator can be switched on, locking out the other breaker. Basically a lockout.

My panel is a siemens so I think it's this kit.
https://www.amazon.com/MUR-200A-Murray-Siemens-Generator-Interlock/dp/B014ECGCQK/ref=pd_sbs_60_8?_encoding=UTF8&pd_rd_i=B014ECGCQK& pd_rd_r=FVX5T5SAZVKJ55QTZJYX&pd_rd_w=6nuuz&pd_rd_w g=Z9XDJ&psc=1&refRID=FVX5T5SAZVKJ55QTZJYX

Only bad is not knowing when the power comes back on. I'm rural so no street lights to give me clue.

I have a generator the same size as yours and an extra one a bit smaller. I decided against tying them or the large one into the house because of the necessity of permits, otherwise if there is a electrical fire the home owners insurance (mine anyways) would not cover any damage.
Sooooo I have a heavy duty extension cord and power panel for the garage (spare frig, freezer, heater and tankless hot water heater. I have two more cords and panels for up stairs that cover the fridge with my wife and daughter's meds inside, freezer side of it, computer, some lights and internet router, ETC.

I have used them once when we had the bad fire years ago and most all power was cut everywhere for about 24 hours. They both run quietly and a tank of gas last 20 hours.

If you are going to hard wire it in as mentioned earlier you will need a method to sense when power is coming back which might be built it to your unit and it disconnects itself as mine do (not needed though). What will cause big problems is if the power does not come on at 60 HZ and full voltage to your house. Voltage can be lower but frequency must match. As an example US Navy nuclear carriers and submarines have special generators that run at 15 HZ output to run the reactor cooling pumps at low speed when the reactor is shut down. They can be run up to 60 HZ if needed in an emergency BUT it has to be 60! On the USS Bainbridge CGN25 the # 2 electrician control panel was going to use the Rx cooling generator to allow the normal ships generator to be shut down. He thought he had raised the frequency and the meter showed a match but it was at 15 HZ and when he through the breaker switch it made the whole stern of that cruiser jump and burned up the breaker and exciter for the generator! What a mess. So frequency has to match.

I hate to admit last time I knew it was back when a neighbor/friend posted it on facebook.....;)

John not sure what you're getting at?
We haven't had a "brown out" since I was a kid, 45 years ago and never since being here. I'd never run the generator without turning off the mains. New generator also has a meter on it.

We get the one bad storm every 4-5 years, over an 1-2 hour outage has only happened 3 times in 20 years. Northeast blackout of 2003 was the record at 23hrs, that was broken two weeks ago with a big blow and several big trees across our road lines, 26 hours. Crews were very busy that weekend, lots of trees down all over.

I'll have to live without a power back on indicator.

What you need is a manual 3 way switch rated for 200A.

https://www.lowes.com/pd/Eaton-200-Amp-Non-fusible-Metallic-Safety-Switch/3012381

I was worried about a frequency match up if the automatic switch unit had troubles. A "brown out" is dropping voltage and we used to get those all the time until SDG&E starting buying electricity from Mexico. In the area south of San Diego we don't get them because of Brown Field and all the border security facilities we have. A manual switch would work like the one James showed but in most areas a licensed electrician would have to get diagrams, install it, get it approved by the city and probably the power company since you're connected to them? That last stuff is why I use extension cords.

frequency only matters with make before break transfer switches and those are going to be more expensive.

I like the device in the 3rd post,. cheap, safe and effective.

the one you listed from HD is pretty nice too.

as far as knowing when power comes back on the one from HD should automatically transfer back.

if you run 240v you have to think about load balance.
unless you need 240 I would run 120.
either way I would figure out what you want to power and move them around in your panel to either balance the load or run everything off of 120.


BTW, I live in SC, so we have hurricanes. this last one was the first that I have had power out for any length of time, about a week. it really was not too bad, no hot water only last day or so. 80gal tank kept it warm and we used it sparingly.
still not worth getting an EG. you have to run them enough to keep the carbs from gumming up.
I do have one know ONLY because it was free.

Something to consider

https://www.homedepot.com/p/GenerLink-30-Amp-Meter-Mounted-Transfer-Switch-with-75kA-per-Phase-Surge-Protection-MA23-S/301962070?cm_mmc=socialmedia|P|FY18|BaseAdditional |FB|ALL|FullFeed|144035735|144035688|143984961|&k_ clickid=e251aae3-014d-4f3a-a0dd-0c87483056be

https://images.homedepot-static.com/...-s-64_1000.jpg

Briggs and Stratton has a similar system, but is designed for up to 200A

My meter is along a walkway, right about head height.
If it stuck out more someone is bound to wack their head...most likely me. :rolleyes: