# IS THERE AN ELECTRICIAN AMONG US?



## Imacman (Aug 30, 2010)

Hello All… wasn't really sure where to post this, so I'll try here, seeing as it involves electric power and safety.
My shop is under construction, and I plan on running the wire this weekend. I have more than a basic knowledge of power…but not a whole lot more. here's my question,.....

• The plan is to install a power inverter in the shop to suppliment my power needs, with the goal being to have a self sufficient building. I will be installing two 100 watt solar cells on the roof that will charge 6 Deep cycle batteries wired in parrallel, In addition to this I will have an "Intelligent Charger" wired to the setup to ensure the batteries are always topped up. I am also running a power cord from the house to the workshop, this cord is on a 15 amp breaker (120v ) inside the house. What I would like to do is have both the power from the inverter, and the power from the house run to a switch that I can switch between "Grid Power" and "Inverter Power".... the power from this switch would then be routed to a small pony panel, that would in turn be wired to the outlets and lights in my workshop. The pony panel will serve obviously as a power distribution point…but also as a main breaker so I don't have to leave the shed and go back into my basement every time I pop a breaker…lol…Lazy lazy I know…lol. So my question is this, is there a switch that will do what I require…or will I have to rig something up?.. ( I Know… I don't like the sounds of "Rig something up" either…lol ) If so what is it called??.. I'm thinking Double Pole, Double throw?? Any help and or suggestions is greatly appreciated!

Thanks

Paul ( Imacman )

Newfoundland


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## canadianchips (Mar 12, 2010)

Yes there is such a switch.
By code you are required to install a switch that will prevent any power (generator, solar or whatever) entering the grid. IF THE LINEMEN are working on GRID and they cut your power you DO NOT WANT your supply going into their GRID. 
f I recall the name of the switch you are wanting to use is aTRANSFER SWITCH. If this is wired properly it should prevent backfeeding into the main line and possibly killing a lineman working. 
Contact an electrician ! Do this properly.


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## Imacman (Aug 30, 2010)

Ahhh very good point, Although I'll be running the wiring myself, I will have a qualified electrician finish and connect it all, If the information thats been given to me by the "Solar power guys" is accurate I won't actually need the Grid power… if thats the case, i'll be having the electrician / power company install a grid tie in, so i can startv selling the excess power back to them!...lol… thanks for the reply.

Paul


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## Chriskmb5150 (Dec 23, 2009)

I used a double pole, double throw switch similar to THIS ONE in my old house. We get crazy storms around here so I used it on the main to switch between grid power and a 10KW generator when the lights went out. Im a master HVAC mechanic so im familiar with electrical but i made sure to get an electrician to check my wiring as should you.
Good luck


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## FatherHooligan (Mar 27, 2008)

200 watts does not sound like a lot of power, will this be sufficient for your shop?


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## Imacman (Aug 30, 2010)

Hi Mark, the Solar Charging Panels are 200 watts total, so that's 200 watts of charging power, keeping a Battery Bank Charged, The actual power availble to me will be 3500 Watts Continous with 7000 watts Peak, So it would be similar to running off of a 3500 Watt Generator that can actually hand more.. ( Start Up Voltages )

Cheers

Paul


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## FatherHooligan (Mar 27, 2008)

Ahhh, I thought you would probably have thought about that


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## GPM (Aug 26, 2010)

I don't know where you live but most utility companies now must allow "net metering" which means you can store your solar power with them instead of batteries. What that means is when you are producing power by the panels and it isn't needed it turns your meter backwards. So later when you use power you are first using up what you gave to the utility company. In the end this is much cheaper and easier than batteries. Batteries are a pain and require maintenance and constant replacement.

There are complete simple kits to do a utility interconnect. You are allowed to do most of the work yourself and then have an electrician review it. Then the power company will check it and if it is OK they will allow you to connect.


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## BertFlores58 (May 26, 2010)

I think the best will be a relay contactor. This is very safe because one power can be use in one time. There is no danger of switching both. Single throw and double pole is all you need. There are switches available but very rigid when it comes to bigger power requirements. You can have a relay contactor and the coil switch will just be a normal selector switch needing only a small current. Coil switch can also be fitted with automatic control sensors such as photo sensitive switches, underpower switches (meaning if the power from solar is not enough then switches back to outside power) and many others… However you have to ensure that there must be a delayed loading of your equipments.. otherwise there will be a big surge of current to your lines and contactor which will overload. For added protection to the contactor there are some current rating overload relay that can be connected directly to the relay.. Hope this help.


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## TopamaxSurvivor (May 2, 2008)

200 watts of charging power isn't going to keep up with much use off the inverter. I know people who live off the grid. They use generators for most everything that uses a motor. 200 watts isn't going to power your shop for much more than lighting.


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## Imacman (Aug 30, 2010)

Thanks For the Info GPM and BERT, I will discuss with the electrician,

TOPMAX, Thanks for the response, I must have not been clear when I worded my "Power Setup explanation". The available power to me is Not 200 watts… the available power is 3500 Watts Continious with a 7000 Watt Peak for surge & start up voltages… ie a refridgerator will spike to maybe 6000 Watts at startup then settle at it's nomal operating current draw. The 200 Watts comes from two 100 watt Solar panels… these solar panels are hooked to a charge controller…. that is hooked to 4 Deep Cycle batteries…. these batteries are hooked to my 3500 watt Inverter. The charge controller monitors the batteries, and feeds a 200 Watt charging current to the batteries as needed….once the batteries are full it automatically shuts off. So the 200 watts is charging power. On a sunny day from sun up to say 6:00pm the charge controller will be topping up the storage batteries. Most of my work would be done in the evenings & nights, so the storage batteries will charge up all day with no current being drained from them. In addition I will have an itelligent charger hooked in that I can switch on at any time to charge the storage batteries..for dyas when there is no sun. so the charging current from the solar cells is greatly reduced. Hope this makes more snese.

Paul
Imacman


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## Imacman (Aug 30, 2010)

I reread your post Topamax…. I think I see what you're saying….. I wondered if 200 watts of charge would be enough as well, the Solar cell Company told me that fro my application 200 wats will be more than enough. for example, a fully charged storage battery set up… can run my lights, and say one power tool for maybe 3 hours… doesn't seem like a long time…. but on any project build, the tools are actually only in operation for only a few minutes and in most cases only seconds. At the end of the day, if the inverter / solar set up can only run my lights and computers I'll still be happy enough with that. having said that, The Solar Cell company tells me that my set up will be more than adequate…lol… but as they say… " the proof is in the pudding". the biggest factor is ofcourse how many Storage batteries are wired together in parrallel…. the more batteries the longer one can operate the inverter..and the less drain on each individual cell. the batts Are about $100 each, I plan on starting with 4 but I'll probably continue to add Batts until I have enough to not have to worry about it. Any thoughts and suggestions are greatly appreciated.

Paul

Imacman


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## TopamaxSurvivor (May 2, 2008)

I understood all of that. 200 watts of charging will take quite a while to put 3500 watts of power back into the system. For running small loads like lighting, computers, ect it should be fine. Running motors for shop equipment, i think you will be disappointed with the 200 watt input to this system.


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## PurpLev (May 30, 2008)

I'll second Topamax. not only that - Once you discover the power of power (no pun intended) you may want a more powerfull saw, or another power tool to add to the team… add DC to that (which run almost constantly at peak performance and for the longest time in the shop) - and you'll be running out of batteries quickly.


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## TopamaxSurvivor (May 2, 2008)

I suppose I should mention I live off the grid in our RV quite a bit of the tiime. I have considered solar charging for our batteries. I usually run the generator at least 2 hours a day for charging. When I see 5 amps on the 120 volt ammeter, I know there is no way I could keep up using solar without a very substantial investment. I would need to have 6 hours of 200 watts minimum and I am not trying to run power saws or other equipment. The other people in the area use generators to pump water from their wells. They don't try to run power tools off their solar systems. I have talked to them about their experieinces, solar is over rated as to teh ampunt of power you can collect and save even though the cells are 1000 times more efficient than they were 10 years ago.


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## Imacman (Aug 30, 2010)

lol.. I'll third the motion!...lol…. charging dead batts with 200 watts will probably take days… no doubt. The viablilty of it will all depend on usage and current drain of course, The Automatic switching between charging devices will hopefully keep the batteries closer to full than empty. the solar cells will have all day to top up the charge and if they don't do it, the switching circuit as suggested by Bert, will kick in the Heavy duty charger over night to keep them at peak. I'm pretty sure that this set up will at least run my lights and computers and a few small power tools for a few minutes….. but it would be hard pressed to run my 15 Amp table saw for very long I'm sure…lol… All I know is… my; little "Alternate Energy" project is sure to make an interesting one…. next step…. add a DIY HHO Cell to run my 4000 watt Generator!...lol.. I'm reading amazing things about that stuff as well.

Paul

Immacman


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## GPM (Aug 26, 2010)

A couple more things - first 200 watts of panels is going to literally take all day to accumulate 3500 watts. However if you are connected to net metering then it will just keep dumping power into the system as long as there is sun. If you are intent on using batteries you may be very disappointed that when you want that 3500 watts it isn't there.

Regarding switching, I cannot caution you enough. Do NOT try to hook up any home made electromechanical switch. If you get it wrong then you have big problems like sparks and fire, etc. You must either use a manual throw double pole, double throw switch. With this switch it is literally impossible to have both power sources connected at the same time if it is wired correctly. Otherwise BUY an automatic switch that is designed and tested for this purpose. But they aren't cheap.


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## TopamaxSurvivor (May 2, 2008)

Doing it as an alternate energy expirement or adventure is one thing. Doing it to save money is quite another. The solar panels and equipment necessary is quite spendy. The payback period will be a long time coming. I have looked into this a little. Being an electrical contractor, I can buy some of the equipment wholesale and wire it myself. Even getting solar cells and building my own panels, I can't really see where it is worth while. I'm sure the costs will continue to come down as more of the items are put into mass production.


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## Manitario (Jul 4, 2010)

Interesting discussion. I too have dreamt of powering my shop with solar power, but one brief calculation of the wattage I'd require for running my table saw and dust collector combined (~3700W) tells me that I'd need a lot larger solar system than I think I could ever afford.


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## Imacman (Aug 30, 2010)

No fears there GMP….. I wouldn't attempt to buid a switching circiut, even with 'Plans"... if I can find one on the market that suits my need, I'll buy it. My intention id to purchase a simple, properly rated DPDT switch, as you mention it's impossible to access or transfer power this way…it's either one or the other… whih is the way it must be. Although I have a keen interest in having a selfsufficient shop… I'm fully aware that the economics of it are just not there… a basic home set up… takes over 10 years ( in cost savings ) just to pay for itself…and that's just for a setup that might ….might reduce your monthly electric charges by say 25%... the good news is yes… the technology is getting better, and the day will come for everyone to power their own homes with out it costing an arm and a leg. I have a 3500 watt Inverter in my motor home and can run several small items on it pretty much all weekend when camping, so I do have some idea of what to expect, It will certainly be interesting to see for sure…

Imaccman

Paul


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## reggiek (Jun 12, 2009)

I have a friend that owned an auto repair shop (he sold it and retired to CO). He converted the shop to active solar - the shop is not off the grid. The solar was for supplementation and cost reduction. The shop got acceptable power from the cells (the entire roof is covered in collectors and a few banks on the ground near the building). There is almost an entire room stacked with batteries…and a hugh wall of dials and switches (it looks complicated and technical - even though it is fairly simple).

The system is mostly self sufficient….and the need to draw power off the grid is minimal - mostly for short winter days or storm systems - (plus with the law in CA - the utilities are forced to buy your surplus power). I believe we calculated the cost - including solar credits and rebates - to be recovered in 15 - 25 years. That is not a quick return by anyone's clock and certainly not when you factor in the required substantial outlay up front.

For now, I believe we really need to pump the money into research and development….and give more credits and incentives to green power development and useage. To date though there is not enough inexpensive alternatives to the expensive power grid….

I am working on using passive solar for heating (water and space) and cooling (space) in my shop. Right now I have a passive cooling system buried in the ground near my shop to exchange hotter ambient air with air cooled several feet underground….I have seen an approximately 5-10 degree reduction overall… not enough to keep the shop comfortable in 100+ degree days…but the system certainly needs some tweaking and some improvement (most of all enlargement)....

I am designing my own solar water heating system that will provide some space heating for the winter months…(this is a much easier proposition as I plan to supplement the solar with my fireburning stove's heat - Heat is definitely easier to capture and exploit). I also plan to use some of the hot water for the laundry room that is in an adjoining room to my shop.


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## TopamaxSurvivor (May 2, 2008)

I have considered these and other self sufficiency systems extensively 20-30 years ago. I had a neighbor who spent big bucks for solar heating for his house that he said was a waste of money. I have worked on retrofitting "green" buildings to make them usable. Bottomline always comes to return of capital investment and under preformance. Now it is a moot point for me, I won't live long enough to break even ) I have calculated to total cost of more efficient vehicles; usually they are worn out by the time you make any real savings!!

Here in WaterWorld, Weatern WA, there are too many overcast days. Although, my solar lights that light my flag work year around!! )


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## Imacman (Aug 30, 2010)

Thanks guys… trust me ..I have no illusions….. I wish I was close to a river…. a water turbine is the way to go for sure…lol.. I would install a windmill ( very windy here )...but I'm to close to the neighbours, and the speeds it would reach would have everyone including myself on edge. As I said… if I can power my lights & computers a few hours a day, it'll make a great little hobby monitoring the In & Out current flows. In regards to heating, I have the plans for the solar beer can heater, there is a local manufacturer here in Newfoundland doing very well with it, It's a one day build once you have the materials, and it's a proven system, made from about 250 aluminum cans in a rooftop installation. Again…it'll make a fun project. The underground air cooling is a great Idea I've thought about as well… I've invisioned it has digging a very deep hole, and pouring a concrete box say 15 feet down and then insulating it to keep the temps inside cool, then pulling air from the shop down underground through some aluminium baffles in the box…and finally back into the shed… I'm sure it will drop the temps by a few degrees at least…. in my imaginings at least…lol…

Paul

Imacman


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## Imacman (Aug 30, 2010)

EUREKEA!....I"VE GOT IT!...it just hit me!!!!!... if we could find a way to harness all the 'Hot Air" that is spewed out by some of the sales guys at some of the Solar Energy Companies regarding energy generation claims….. we'd all have unlimited power wouldn't you say?...lol

Imacman

Paul


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## TopamaxSurvivor (May 2, 2008)

If the hot air out of WA DC were harnassed the whole world would have free energy!!

I thought about the underground cooliing tube many moons ago, but we don't have enough hot days to make it worth the effort here is WaterWorld 

Have fun with you new adventure.


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## GPM (Aug 26, 2010)

I think we are all interested to see how your system works out. Any thinking person (it is a given that most all woodworkers fall into this category) would want to use some solar/wind power if possible. Keep us posted and good luck.

Note: like some of the others I have been looking at these things for decades and of course the economics prevent any large scale installations. However, there are some situations where the payback is quite reasonable. A great deal has to do with where you live of course. But if you are in the southern half of North America you can break even on solar water in five years. Regarding solar electricity the panels have dropped in price by I think 50% looking at cost per watt. It still takes a L O N G time to recoup the investment. However, if you drop the batteries and use the utility company as your storage it does make the break even point shorter. In the US the federal government gives a 30% tax credit for hardware costs and some states do the same.

A final thought is that after working in the third world for twenty years I know how to reduce your electricity costs to zero. You simply climb the pole and hook up a #6 wire to one of the hot wires and run it to your house. Be sure to cover it with some dirt for safety. You cannot imagine the creative electrical supply and distribution things I have seen…


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## Imacman (Aug 30, 2010)

I will certainly post my progress and findings GPM,,..... Interesting…your last paragraph regarding creative electrical supply… when I was a kid, I had a facination with electronics…lived at radio shack after school, for christmas my folks gave me the "150 In 1" electronics kit, and i'd spend hours wiring things up…. My electronics hobby in my bedroom led me to discover that the phone jacks at that time had a 40V ringer voltage I think it was… i use to tap into that for power for experiments…lol.. you don't want to be holding the wrong wire when the phone rings…I'll tell you from experience…lol… never the less I'm told there is still an accesable 'Free Current" running through the phone jacks….and that some creative people do indeed use that source for diffrent things. Hmmm I wonder if a transformer would get the voltage to 12 Volts…just enough to run my Power inverter…..lol…. in the words of Albert Einstein….. " Inteligence is NOTHING without imagination."... lol I wonder….... hehehe

Imacman

Paul, Newfoundland


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## Imacman (Aug 30, 2010)

LOL… Heres an interesting lin i just stumbled on…lol… I think the guy is serious too…lol

http://www.sandman.com/telco.html


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