New and improved energy management device.

I made two energy management devices for my two generators 3500 w RV generators. I want portable generators to use at any of 12 different locations. And there is no way I want to have them within 100 ft of a house and have exhaust get inside. I choose to go with RV generators because I want to have 30 amps coming out of one place. You can't say that about larger generators. Most I've seen are only 20 amps, 120v out. I'm sure there may be larger generators for RV's that have larger outputs. But I'm cheap and happy with a 3500w one.

So I wanted to use a small quieter, more economical RV generator. I also wanted to use my generator to be portable so I can power hedge trimmers, small water pump, 4 hp chainsaw which requires 70 amps when it first starts, power up a 3/4 hp well pump, refrigerator and small appliances like hot plate, coffee pot, toaster.

So here is a brief description of how it works for house back up power. When the well comes on, everything else is turned off. When well is off the small appliances gets power, then up to 10 minutes the refrigerator gets powered up. This way my largest load, the well, gets the generators full attention. It's no big deal for me to put 2 cords through the kitchen window and rest them on counter. No big deal to put a wire through basement window and power pump.

When when I use the 4 hp chainsaw, I have a large diode placed in series with saw for 1 second. The saw is only getting half waves, half the current and 1/4 the power. I use the diode to get the armature going, produce a reverse emf, limit starting current to 35 amps. One second later, the saw gets full voltage and uses normal current of 15 amps. This prevents the generator from shaking for about 3 seconds when I start the saw.

The bigger box is my first generation. The smaller box is the same, just more compact.

Everything except for the 1 second timer is old school parts used 50 year old furnaces and AC. Most of the parts I already had sitting on the shelf.

I've thought about similar projects just never did follow through and build them. You put a lot of thought and work into this and it sounds like it does all that you want it to do. Pretty neat,,A+

I'm assume you have one, but it's worth mentioning that a transfer switch is required when you connect a generator to anything on a household circuit. The main breaker should not be used to disconnect from the grid.

I put in a transfer switch and they work slick. If you have any knowledge about electricity they are simple to put in.I put my 12 circuit switch in under an hour. With switch in you never have to touch the main.

I use 3 extension cords. No need for a transfer switch. Don't want a big generator to power up the entire house when I can get buy with a 3500 watt RV.

(quoted from post at 15:57:48 01/20/15) I put in a transfer switch and they work slick. If you have any knowledge about electricity they are simple to put in.I put my 12 circuit switch in under an hour. With switch in you never have to touch the main.

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Everyone that I know that has put one of those twelve circuit switches in calls the electrician back after the first two day outage to put in another twelve circuits.

George, that first gen. Looks familiar, did you put it on here when you built it?

This one is set up to run everything that we would need in an outage. Well ,gas furnace,refrigerator,power to gas cooking stove and microwave ,lights (90% LED) and tv that takes care of anything we need. This can be taken care of with a 8,000 watt run 10,000 watt surge generator.

I would not want to be the lineman that comes near your vicinity and find that your back feeding to a transformer. Do not put your Power Co. employees at risk.

Who said anything about back feeding? I would never back feed. So how my post went sideways with the posting of a transfer switch.

I even said I have no desire to power up the entire house, my goal was to power well, refrig, and small appliances via extension cords. Never would never think of using house wiring. My well has a power cord I can easily remove from an outlet and plug it in to an extension cord.

I may have, but it's been modified with a second
timer, contactor and a very large diode for saw. So
The box now can be used on a saw, well, refrig, and
hot plates, multi functional device.

Disclaimer, I'm not back-feeding in to power grid.
I have no plans to do so in future. I'm not using
any house wiring, only extension cords.

I did that on a manufacturing plant with 25MW of generation. We monitored the kW, had a table of consumption for each device with priority levels. I would then enable that device to run in the PLC over the network.

You must have a plug on your well and not hard wired into main box. You generator must get a work out to start well pump because 3/4 HP well will draw any where from 2,800 to 5,200 watts on startup. You say your running three cords 100 Ft.from garage to house how heavy of cords are you running for that distance? My garage sets 80 FT. from house and I am runnig one 100 FT. 10-4 cord and generator puts out 8,000 runnig watts 10,000 surge and is a 30 amp generator. I looked at a lot of generators before I bought mine and every thing that I looked at over 7,500 12,000 watts were all 30 amp generators.

OK what happens when the chain saw is used on house current ?? 70amp start up .

Funny how that always happens even when it's already been addressed ain't it?

Simpler, cheaper , lighter , more efficient and more flexible to power a VFD from the generator. The. Plug the loads into the VFD. The VFD will provide current limited soft starts. Even variable frequency and voltage to control rpm of induction motor loads.

George, you would be an interesting neighbor, and I mean that as a compliment. Nice job - you're a thinker.

You have no idea!! I live about 40 miles away.Some days when out in woods one can sense the brain waves!!!!!!!!!!!!!1

Yep, the peak current is 70a. Because there are many ft of 12g wire in house going back to load center then to transformer, the current my be slightly less, 65a, due to IR loss. The peak current is just for a very short time until rotor generates reverse EMF, perhaps ms. It however shakes the gennerator for about 3 seconds before it recovers.

Yep, 120v cord on well because I designed a water sensing circuit to turn well off when it detects water on basement floor. The water sensing circuit works well. It been tested and proven 3 times. When I don't have water, it's because of a plumbing leak or rain gutters need cleaned.

I plug well in to a GFCI. The water sensor trips the GFCI when it detects water. I find it difficult to comprehend that a motor gets along with a GFCI, even when the pump is in the well.

I also have the pump power factored. Needed a little over 200 mfd's. My generator can start the well much easier than the 4 hp saw.

How can the VFD turn my refrig and coffee pot off
when the well is on?

Keep in mind, most of my parts were used, just
sitting on the shelf, including the large diode
which would cost a pant load.

Yes, if I had to buy everything it could get a
little pricey.

If this were made commercially, the transformer
could be eliminated by using all 120v coils in
relays. Everything could be mounted on a circuit
board. That would cut down on weight and size
considerably. Getting a diode to handle the saw
will be the only hang up. Perhaps that would be
where a VDF would be a good idea.

Now, that I have all the bugs worked out, I need
to invent something else to occupy my time with,
especially in the Winter.

Ok your well runs on 120v mine is hard wired in 240v. It's great that you know how to hook all that up. I was going to go cords but instead of cords I went transfer switch . I changed my mine about having cords laying all over the place and doors that would have to be altered for cords so they would close.I have one generator,one 100FT.cord and a transfer switch with 12 circuits. I enjoy seeing some of things you come up with.

Yep, Many times things take on a life of their own, not related to original post. Good chance I'm as guilty as the next too.

Bill,
You were my neighbor once, next room over. You taught me all the physics I needed to know. Bill's law of physics: You can't push with a rope. Long enough lever and you can lift anything. And something about you can't put 10 gallons of something in a 5 gallon bucket.