Right up front, I want to acknowledge that I know what I'm discussing is
potentially unsafe and probably illegal. That being established, I'll
I am the *only* person in the house who would go anywhere near the breaker
box, much less throw a switch. I am also keenly aware that an improperly
connected generator backfed to a main panel can injure a line worker; and I
can assure those concerned that I am familiar with the necessity and
procedures for isolating the generator power from the public grid. Under no
circumstances will my generator be connected unless the main breaker is
So, assuming I don't royally f*ck up, tell me the truth. Is it truly
feasible and practical to provide power to the house by backfeeding to a
wall outlet from the generator? I'd only do this for providing "comfort"
power (lights, tv, etc.) while providing direct power via extension cords
for major power users such as frig, freezer, etc.
Without a long discussion about the legality, and assuming I'm a reasonably
intelligent adult with enough sense to not electrocute myself or burn my
house down, is this a workable solution?
Apart from the factf that it is careless, and dangerous, you are likely
going to be feeding through a 15 or 20 amp outlet. That will flow back
through a 15 or 20 amp breaker. And this circuit is just one side of
the 240 volt service. Any loads (about half of them) that are connected
to the other side of the service won't see any energy. This isn't
enough to be comfortable when power goes out. Both meters on my system
sit at about 25 amps when we are without power and are conserving.
Do it right and put in a transfer switch, also called a safety switch.
It's not difficult and it is the right way not only because it is the
right way, but it works much better.
Chances are (no pun intended), I'm not going to do it at all; but the
circumstances behind the question are that we have a substantial ice storm
forecast & I just bought the generator today. I *will* be getting the
correct stuff installed asap, but that won't be before the lines come down
Then why not just run a few extension cords, Alot safer and your not
exposing people or your gen to a possible blow. Also a UPS can Mess
up a generator, as a ups will read a swing as a surge and go to
ground. Even honda with stable voltage doesnt recomend it.
I suspect that that highest danger would be AFTER the power is restored.
A "typical" SUICIDE cord would have MALE-MALE connectors: one each for,
say, the dryer outlet and the generator outlet. Or it would be a cable
"hardwired" into the panel via a 2-pole breaker with the other end a MALE
connector to the generator.
When commercial power is out, the only danger comes from your generator.
The linemen are "safe" if your main breaker is open. You are "safe" if the
panel end (or dryer outlet end) of your SUICIDE cord is attached or plugged
in. The danger in installation is that if the power comes on while you are
working (ASSuming you forgot to pull the mail breaker FIRST) you will get
While you are operating the main danger comes from you MALE-MALE
"extension" cord. If it pulls out of the dryer outlet, you have a LIVE
MALE CONNECTOR! Since that "extension cord" will, likely, be running
through a partially open window, anyone might be tempted to unplug and toss
the cord outside and close the window. YOU might do that if you are not
When the power is restored you first impluse might be to leave the generator
running while you "test" to ensure the commercial power is good. If you
"miss" the breaker going to the generator when you turn the main breaker
back on you might get a surge that can damage the generator before the
breakers can trip. If you decide to "unplug" the generator you end up with
a HOT MALE connector.
If you think clearly none of this will happen. But after a day or two or
three or four of running about looking for fuel and load managing the house
you might get sloppy.
There is a REAL danger.
Unfortunately, you can buy a ready to go generator from Wal-Mart of less
than $500. It will cost you close to that much money to pay for and
install a load transfer panel that will only switch some of your stuff.
You can buy the stuff to make SUICIDE CORDS at any hardware store. But you
can't find a relatively inexpensive source of Double Pole Double Throw
(DPDT) switches that might make it safer and easier to use your generator in
What's "funny" is that the local volunteer rescue squad/fire department has
a big sign out saying: Buy a Generator NOW! Since I live in an area where
many folks get their water from private wells they should either take down
the sign. Because if you are on a private well, the MAIN thing you want
the generator for is the run your pump.
If you've come here looking for absolution for this unsafe potentially
deadly technique then do what the hell you want and pray you don't end
up on trial for manslaughter.
If you want to know how to do it right I will spend all of the time you
need to help you do it right. The cost of a completely safe
installation is not a lot more. When utility workers back feed an
electrical service during emergencies they use a double block and break
technique. They open the main breaker and pull the meter. The
generator is then connected to the meter tails meter end. This is done
for service to hospitals, nursing homes and the like. All you have to
do is tell me what brand and model of panel you have and I will tell you
how to set this up so that any member of your family can do it safely
Oh, yes it is!
You can get a generator for $500 or less. A suicide cord might be thrown
together for another $50.
I suspect that installing just a small load transfer subpanel (which look to
be close to junk) would eat up $150 in hardware. If a "pro" puts it in,
you are talking about another $100.
A "whole house" solution can cost a substantial fraction of the cost of an
entirely new service.
What is/are needed is/are CHEAP ways of getting you generator SAFELY
Here's my DIY panel:
I chose SPDT switches with a large break-before-make transition, and
to the transfers with the genrerator off.
Note that the circuits don't have overload protection in generator
mode, but, since the gen only outputs 3000W, and shuts down at about
28A, I didn't add breakers.
To help juggle loads, I added a remote meter at the top of the
basement stairs, fed by a current transformer in the transfer switch
I already had a small subpanel box, which I stripped, cut, added the
switch support, etc. I don't think it cost over $150, while dedicated
transfer panels with the same number of circuits were over $300.
Downside: One of the switches went permanently open when I
transferred the kitchen quickly under load. The refrigerator was
probably running, and the inductive kickback of the compressor motor
against the steet supply killed the switch. The main panel breaker
did not trip on this "overload"
I'd probably do it over if I could find SPDT breakers that could
handle overload protection AND transfer in one unit.
To reply, please remove one letter from each side of "@"
Spammers are VERMIN. Please kill them all.
The other downside to this is that if you attempt to sell your house you
may well have to remove it since it doesn't comply with the NEC.
Additionally, insurance companies are looking for ways to avoid loss
payments with greater frequncy. They'd likely give you a hard time.
Doug Warner wrote:
The problems with the DIY transfer panel are: 1) only 120 volt loads and be
switched; and 2) lack of protection since EVERY circuit could draw 28 amps
including "lighting" circuits which are often only 15 amps.
The NEC owes it to the American Public to properly address the home
generator problem. When they look at things hard they take account of
human nature. They may well find (or encourage others to find) cheap ways
of backing up the home power with a generator.
That would be 100% up to the buyer (and whoever writes the mortgage.)
Houses are routinely sold (with FHA loans) that have sub-standard wiring.
There seems to be a "don't ask, don't tell" about this sort of stuff.
In what sense? I have lost count of the number of home insurance policies
I have had on various places and NOT once has the company inspected the
wiring. The ONLY thing one company did was to send a guy to walk around a
house we got at a bargain to ensure that is really was as big as we claimed.
If a house burns down and it is caused by faulty homeowner wiring in most
places the insurance company will still pay. If they don't pay they risk
the state regulators fining them. If it goes to court, a jury of
homeowners (each of whom likely has a bit of "faulty" wiring) will take the
insurance company to the cleaners.
Where I live, insurance companies can't hide behind pages of fine print. If
they want to get into the wiring inspection business they can; but if they
do, they have effectively "approved" the situation which can expose them to
third party liability directly rather than as an insurer to the homeowner.
In practice, the companies recognize that they are PAID to assume these
risks. The collect the money and if something happens they pay up.
The only crisis in homeowners insurance comes when home prices are falling
and the only way homeowners can "cash out" is for an "accident" to happen.
If you backfeed the electric dryer outlet with the 220V output from your
generator, it should work OK if the main disconnect is open.
Make sure you connect the neutral or you will have weird and dangerous
Manual transfer switches use CB's to protect the branch circuits.
GEN--OFF--LINE switches are used in manual transfer switches to isolate the
load(s). It's a known fact that regular CB's sometimes can and do fail
closed. Learn how to post so people can follow who's saying what.
Well, there are appoved panels that have a mechanical interlock to ensure
that only one of two breakers is engaged at any time.
IOW: the type of failure you described is considered rare enough that it
isn't considered to be a serious safety issue.
Which is exactly what the OP said that he is _not_ interested in using.
Electrical accidents are often due to either poor wiring or ill-advised
behavior on the part of the victim. I can fully understand that some people
who have never seen a breaker that won't open when turned OFF and/or trip on
short-circuit can come to the ill-advised conclusion that it's a rare
occassion; even assume that just because they turned a circuit OFF that it
is deenergized and further arrive at another ill-advised conclusion that
checking for voltage is not necessary. Interesting how those persons are
usually the very same people who make the biggest stink about it (if they
are still alive) when/if something does happen to them or others regardless
of fact that their actions were based upon their own ill-advised
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