induction motor grid tie

[seyffer]

I am trying to get away from using grid power... or at least make as much as i use.. i have looked at many ideas over the past years.. hydro.. wind.. solar.. even generators.. i have come to the conclusion that the induction motor route is the best for me.. i have a small house an a Big shop that eats me alive on electric day.. i need help hooking a induction motor to the grid the right way and since i know nothing about how.. I'm at a loss on this subject.. i do read that if a induction motor is spun slightly faster than its rated rpm (50rpms or so) it will make power rather than consume power and it will also stop making power if it senses no power from the grid so this seems very safe to operate.. i have read (in the past month) so many things my mind is blocked by to much info.. anyone know how to do this? in simple terms..

Thx

[dnix71]

Where are you going to get the mechanical energy to drive the induction motor overspeed? There is no free lunch.

Can you give up a short rundown of your loads (exactly what shop appliances and how long you run them).

It's pretty hard to make electricity for less than you can buy it, unless you can get waste veggie oil for free, or you can install a large homebuilt turbine.

Conservation is the fast free way.

If you have a source of free veggie oil, a Lister type engine/genny can easily run your shop tools.

[seyffer]

i have read some posts on here and my free lunch is the H word driven gas motor so dreaded to speak of on here... not sure why but anyhow.. i have run a 10HP gas engine on the H word for over 24 hours with no problems.. it works fine don't need to store anything make it on demand.. system shuts down when no current is detected (motor stops).. it either burns it or shuts off.. just need to know how the induction motor is to be run and connected to the grid safely.. i wont mention the H word again but that will be the driven force of my project.. the free lunch..

Thx

[dnix71]

H isn't a source, it has to be made. Once made it can be used as fuel. The usual method of making it involves lots of electricity, which must be why your bill is so high.

If you just like experimenting, fine. But you will not and cannot lower your electric bill by using electricity to make H then burning H to drive a motor to make electricity again.

If you forceably overspeed a syncronous induction motor about 3-4% (using a belt driven engine, for example) while it is connected to a power supply, it will "buck" and some of the mechanical energy you are putting in will be converted to electricity at the sync rpm (50 or 60 Hz, whichever the motor was wound for). If you were using the grid to power the motor, then you would be converting some of the mechanical energy you are supplying from the gas engine back into the grid.

The trick is that if you push too hard the motor will stop bucking and break away and way overspeed, and if the grid fails, the same thing will happen.

[scottsAI]

Seyffer,

Just as simple as it sounds.

Make sure the motor is rated inverter 100% duty if you want to run it for hours.

Size in HP same as engine plus a bit, due to motor efficiencies.

Smaller ICE engines have an inflated HP rating. As much as 4:1.

More efficient the motor the more efficient generator. Motors come in 70 to 94%.

Look at eBay, price has nothing to do value of motor, just who's bidding.

Add a reverse power detection relay, if the engine fails, don't want the grid motoring your engine.

Once you get above couple HP, motors will be 3 phase. If your power feed is single phase use any two of the phases, leave third wire disconnected. Some say to connect cap it it, helps stimulates induction motor's rotor. (this needs more research).

Do more reading, this is not an exhaustive list of things to consider.

Where is the H coming from?

Have fun,

Scott.

[jonas302]

Acually the H word rule is if you are generating and using it is open for disscussion  they just don't like crazy therorys (:

You might check out the breezy 5.5 brand turbine they use a grid tied inductin motor maybe you can get a controller or some info at there website

[seyffer]

my bill is high because my i run 2 CNC machines... 1 4'x8' laser engraver and 1 4'x4' Plasma table.. 2 plasma cutters.. and 2 welders.. 2 drill presses.. along with 2 exhaust fans.. 3 computers.. 2 7.5HP air compressor.. electric hand tools (grinders sanders drills).. lights etc

your off subject ranting.. Coffee?.. my Question was about induction motors tied to the grid.. (windmills are induction motors) using like an old or new induction motor to make power by turning it with what ever source (maybe ill hire Conan the barbarian or get 2 mules or even a few mice on a treadmill) what ever it may be how to take one and do this in simple terms.. Thanks for all your help!! *dniz71*  

[seyffer]

Excellent! thx