A follow up to my previous (stupid) question, re backfeed, which is now gone from my brain. Further advice needed, so I can communicate intelligently when looking for a contractor to do an install. went back in the archives, but I still have questions.
So, I’m looking at options for how to cut a transfer switch in. My house is set up with a 200A panel at the meter on the garage, with the house running off a 100A sub panel set into an exterior wall that is breakered off the main panel and fed underground. Oh, yeah, GE panels.
Main covers a couple of circuits in the garage and the AC compressor in addition to the sub panel on the house.
My thinking was to set up the transfer to run only the sub panel for the house, and make sure to switch off the oven, steam generator, and air handler at the breakers to avoid overloading a portable generator. Avoids having to cut into the stucco on the house, uses the existing underground feed from the garage, and keeps the generator by the back fence and away from the house. If I had a panel in the basement, I would just cut some lighting and the refrig over to a transfer panel and live with that, which is all I am looking for.
However, most of the commercial product I’ve been looking at doesn’t seem to support the rating of the sub panel, especially the input box to hook the generator into the system below the transfer switch.
I did come across this, though, which SC Edison has approved for use –
Anybody use one of these? it looks like the ideal solution to what I need, but it is something I’ve never heard of before.
jose c.
—
“Though I don’t think” added Deep Thought “that you’re going to like it.”
Edited 8/4/2008 5:46 pm by El kabong
Replies
There are no magic potions, crystal balls, pirates' maps, or shortcuts to back-up power.
The web site is more than a little misleading. All those folks provide is a cord and plug.
The key to safe operation, in this case, is the 'breaker' that they refer to. What they really mean are two breakers, interlocked so that only one can be 'on' at a time. One acts as a 'main' breaker from the PoCo feed, while the other acts as 'main' when the generator is running.
That's 'half' of a manual transfer switch. The other 'half' are redundant electronic interlocks, to make double-sure that you don't have your generator try fighting the grid.
Without the expense of a sub-panel? Excuse me?
Strictly speaking, you don't ever 'need' a sub-panel. You DO, however, need to limit your loads to what the generator can handle. A sub-panel is but a convenient way to make sure that the generator isn't overloaded.
Just as important are the load limitations. Good for 200 amp panels? I'm not sure what they mean by that. Even if your generator was able to provide that amount of power, that puny cord can't deliver it. I suspect that the 'fine print' will reveal a 40 amp / 9600 watt limit.
A final detail, not addressed by this product, is the need to periodically run the generator, under load. This is a very important maintenance detail. Automatic switches can be programmed to do this; with this product, you get to haul the generator out every month.
These are details that illustrate why generators ought to be installed by electrical contractors who have the experience. There are many 'design' issues involved, many judgment calls to make ... it is never as simple as just plugging something in.
" The web site is more than a little misleading. All those folks provide is a cord and plug."No, the main thing that they sell is a transfer switch." GenerLink™ is a five-inch device that is installed behind your electric meter by your local utility or licensed electrical contractor. When you connect a portable generator to GenerLink™ and start it up, GenerLink™ automatically disconnects your house from the electric utility grid preventing the possibility of back feed, which can damage equipment and harm utility personnel. "The one thing that I could not figure out is if the transfer is done mechanically when the generator is plugged in or it it has a solenoid and switches when the generator is running.The main difference between this and the 6 - 8 circuit transfer switches is that it does not even the slightest load management..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill, thanks for the explanation. For some reason, I was having some trouble with that particular web site.
I'm a carpenter working for a design builder of custom homes. Most of our clients are rural and several have opted to having the Generlink installed.I myself have just had one installed in my home and ran a test on it and it performs exactly as advertised.Once the proprietary cable is connected to the unit on your meter base and your generator,you are separated from the power grid, which protects linemen from generator back feed and your generator from being damaged should the regular power be restored.You simply turn on whichever circuit breakers in your 100 amp service you wish to use, up until the capacity of your generator,i.e. a large generator would likely power all your circuits, while you would need to mix and match with a smaller generator.It is easily the most cost effective, versatile and easiest system I've found.As an added feature, for an additional $50.00, the unit comes supplied with an internal whole house surge suppressor-quite a saving over the usual $500.00 cost of having a surge suppressor installed on your electrical panel.
Your house sounds quite similar to ours... a 200A main service panel which feeds a 100A sub for the house.
I installed a Square-D manual transfer switch panel beside the main panel a few years ago; it works well.
I think the critical question to ask yourself is which loads do you want the generator to power during outages? In our case the most important load was the well, which is in the outbuilding where the main panel is, so that is where I put the transfer switch panel. It's merely a small breaker panel with, I think, four breaker slots. When the mains on this panel are flipped one way, the four breakers get their power from the power utility; when the mains are flipped the other way, the same four breakers get their power from the generator.
If you don't have a well, and most of your critical loads are in the house, fed from the 100A panel, then I think you would want to put the transfer switch panel there. Is there a place to put the generator near that location?
Scott.
Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”
Hello EL,
For $20 at a flea market, I found a 200 amp disconnect switch like I've not seen before. With the arm in the UP position, the utility company's power goes to house. When you pull it to the middle, it disconnects the grid like all others. But the arm is designed to travel on downward. On the switch box it is labeled "Emergency Power" and the house is then connected to emergency generation leaving the power grid totally isolated.
I'd guess you'd use your home breaker box to disconnect/trip those breakers and circuits to match the output of your generator or Solar/Inverter battery bank Kilowatt power rating.
Take a look for one of those types of disconnects.
Bill
Have you looked at Gen Tran?
http://www.gen-tran.com/eshop/10Browse.asp?Category=MTS6-16
Impossible is an opinion.
Try this:
http://www.apelectricshop.com/m-42-generator-interlock-technologies.aspx?gclid=CMfYk4TO95QCFQZlswodt12brg