Shopsmith Forums

After the extended power outage this past weekend in the mid eastern USA, I believe emergency generator systems should be concern to some of the Forum members.

The following is my opinion on this subject. I had installed a 5500/6875 Watt emergency generator and a 7500 Watt power transfer kit in 2005 after losing power for 2 weeks in the fall of 2004. I had not used the system since it was installed. However, I tried to operate only our refrigerator with a 2 KW generator I had in 2004. The refrigerator would not start but my Shopsmith Mark V did operate many times from this generator.

After seeing so many power outages lately, I revisited my setup. I found that my generator and most 5500 Watt generators only have a 20 Amp output plug for the 220 VAC output. To get the full 30 Amp output, I would need to use 2 #12 extension cords with a 4 outlet box on the end. So I went to several web sites to see what the starting and operating wattage of each appliance. To handle the minimum requirements listed below, I would need a 10KW emergency generator as a bare minimum.

http://www.kohlerpower.com/residential/ ... umber=103#

Your Power Requirements
Total Running Watts: 3225 W
Total Starting Volt-Amps: 9530 VA
Home Square Footage: 1,000 Square Ft
Appliances: Operating Starting
Refrigerator Significant use 500 W 2000 VA
Garbage Disposal Significant use 200 W 450 VA
Microwave Oven Significant use 1200 W 1200 VA
TV Significant use 500 W 500 VA
Personal Computer Significant use 700 W 700 VA
Security System Significant use 180 W 180 VA
Garage Door Opener Significant use 500 W 1500 VA
Well Pump Significant use 750 W 1500 VA
Stand-Alone Freezer Significant use 500 W 1500 VA

So I removed my 5.5KW generator and power transfer system after purchasing a portable 10KW emergency generator (electric start, 50 Amp output). I will install it in the next week or so. The emergency generators I investigated do not have a wattage/amp gauge so I added a box with 50 amp wattage/amp gauges (MB125) and installed it in the 220 VAC to panel line. I added a 50 amp breaker ( upper left 220 VAC slot in main power panel) with a manual cutout switch to allow only line power or power from the generator. This was much cheaper than adding a higher rated power transfer system. This will give me some basic functions to survive during a power outage. I will be using the amp meters will see what other circuits I can add and/or turn off under load. No hot water or AC, only fans at this time and pray I do not need the system . I have a 2 ton AC in our 1000 sq. ft. house addition which I will try to operate only at night. I plan to test this system in the next few weeks before I may really need it. If whole house AC is desired, then I believe a 20-25KW system is needed which is quite expensive.

I believe the 7500 watt power transfer system was a waste of money since it only allowed 20 Amp input power. Plus these are normally for interior use only so I had to build a large waterproof outdoor box to hold the one I had. 2 12 ga. extension cords allows for the full 30 Amp output of the 5500 watt generator and are much cheaper. Just plug and see if it operates.

I plan during testing to monitor the amp gauges and turn on & off each main electric panel switch and record the starting and operating change in amps. Depending on my testing, I may look into buying a 14-15KW portable generator (will still fit in my outside shed) in the future. I will be happy to offer my opinion if anyone is interested in installing

A 5500W generator will not supply 30A at 220V.

A 7500W generator will supply slightly more than 30A at 220V.

A 10KW generator will not supply 50A at 220V.

These are ideal simplistic limits which do not take into account reactive loads nor load surges.

I would not expect to see a 30A receptacle on any generator rated at less than 7.5KW.

Any refrigeration compressor requires a substantial start current surge capability.

Moving up to 10KW was a wise decision.

Where ya gonna store the emergency gasolene supply?;)

[quote="JPG40504"]A 5500W generator will not supply 30A at 220V.

A 7500W generator will supply slightly more than 30A at 220V.

A 10KW generator will not supply 50A at 220V.

These are ideal simplistic limits which do not take into account reactive loads nor load surges.

I would not expect to see a 30A receptacle on any generator rated at less than 7.5KW.

Any refrigeration compressor requires a substantial start current surge capability.

Moving up to 10KW was a wise decision.

Where ya gonna store the emergency gasolene supply?]

Yes, all the above is true for continious output power. I am not sure most people understand these facts. My 10KW generator is rated at 40 amp continious, 50 amp temporary. Therefore, I am looking at the initial starting amp/current of any motor driven appliance which most generators can supply for a few seconds when determining total amps I need in a generator.

I have 20 5 gal plastic gas cans of gas I store on shelfs in my shed each year since 2005 and then use it in my car and truck after the hurricane season passes. I buy the gas in May and June and start using it in Nov. I use 2 oz of a fuel stabilizer called STA-BIL in each can and have not seen a problem with using it or with the gas. I believe this amount of gas will keep me going for 4-5 days when roads and gas stations should be opened again.

I have been unable to find any portable generator with a single output plug that handles more than 50 Amp. So I may unable to upgrade to a higher amp output portable generator. They have a separate 30 Amp 220 VAC plug so I am not aware of how to connect the 30 amp line into my main power panel as only one panel slot supports the line/generator power cutout. I have not found any box or instructions on how to connect the 50 amp and a 30 amp output cords into a single feed for input to the main panel box. I could change the 50 amp power panel breaker into a 80 amp breaker and use the correct size wire. I am not sure I could build a box that would meet state and national codes for this type of box. Always interested in ideas to accomplish this task.

I looked into emergency power generators and I was told that unless I was going to install semi permanent 27k propane gas unit with a large gas storage tank I was fooling myself.

I was told that a gas engine generator of sufficient size to power anything more than a few lights for longer than a day or two, would require more in gas storage and preventative maintenance than I was willing to give.

A semi permanent propane gas unit installed and rigged in accordance the electric company safety measures was fairly expensive more than a few nights in a Motel and cost of food in freezer. And after 33 years living in the same house that has never lost power for longer than a day I think I will just drive to the nearest Motel with power for the night or two should the need arise.

If not I know where Mayo lives if power goes off he may see me and my wife with sorrowful faces standing on this porch looking in the window.

Ed in Tampa wrote:I looked into emergency power generators and I was told that unless I was going to install semi permanent 27k propane gas unit with a large gas storage tank I was fooling myself.

I was told that a gas engine generator of sufficient size to power anything more than a few lights for longer than a day or two, would require more in gas storage and preventative maintenance than I was willing to give.

A semi permanent propane gas unit installed and rigged in accordance the electric company safety measures was fairly expensive more than a few nights in a Motel and cost of food in freezer. And after 33 years living in the same house that has never lost power for longer than a day I think I will just drive to the nearest Motel with power for the night or two should the need arise.

If not I know where Mayo lives if power goes off he may see me and my wife with sorrowful faces standing on this porch looking in the window.

The door will always be open anytime you want to visit for a while.

Ed in Tampa wrote: I think I will just drive to the nearest Motel with power for the night or two should the need arise.

So how FAR will ya drive of that motel with power?

Ed in Tampa wrote:I looked into emergency power generators and I was told that unless I was going to install semi permanent 27k propane gas unit with a large gas storage tank I was fooling myself.

I was told that a gas engine generator of sufficient size to power anything more than a few lights for longer than a day or two, would require more in gas storage and preventative maintenance than I was willing to give.

A semi permanent propane gas unit installed and rigged in accordance the electric company safety measures was fairly expensive more than a few nights in a Motel and cost of food in freezer. And after 33 years living in the same house that has never lost power for longer than a day I think I will just drive to the nearest Motel with power for the night or two should the need arise.

If not I know where Mayo lives if power goes off he may see me and my wife with sorrowful faces standing on this porch looking in the window.

Well we lost power Friday and it came on at noon only to go out agin for one side of the street so I assume it is a blown transformer. For back up I run a Honda 6500 watt portable hooked up with a single cable through a Generlink (google it) which lets me send power to any circuit I want. I am currently running the 1.5 ton upstairs air conditioner and the tv (cable is working) a fridge and a light or two plus well pump as needed. It won't start all these at once so I have to turn all off and start with the ac and then do a few others.

Gas storage is an issue.

Interesting article even more interesting timing.
Apparently Germany averages 21 minutes of power outage a year.
See why
http://www.cnn.com/2012/07/02/opinion/f ... topstories

Perhaps if everyone that buys backup power supplies, generators and such offered to pay the power company what they spend to do this we would not power outages that last longer than 21 minutes our selves.

beeg wrote:So how FAR will ya drive of that motel with power?

If the hurricanes were any indicator of what to expect I would have to drive 10-30 miles. Here in Florida we have so many separate companies supplying power that if you get off the grid you are on, the neighboring grid will probably have power.


Besides my power comes from the line that serves the Power Company's head pooba, and is less than 2 miles from a main transmission line drop to distribution feed substation. If power goes out they usually have his power back before his alarm clock with battery backup starts to sqawk about the lack of juice.

Also our power lines are carefully checked, tree trimmed and everything tested about once every 2 months. I guess when you are the grand pooba of the power company they want you to have power. And if you are his lowly neighbor that happens to be on the same feed, you also have power