# Portable generator wired into home wiring, yes or no? **URL:** \ **Category:** Factual Questions\ **Created:** [December 24, 2008, 12:50am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482 "2008-12-24T00:50:50Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![BrandonR](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@BrandonR](https://boards.straightdope.com/u/BrandonR)\ **Post date:** [December 24, 2008, 4:37am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/21 "2008-12-24T04:37:39Z")
> [@Ruby](#): > > I’m an insurance adjuster who is just now handling a claim where the homeowner wired his new room addition improperly and caused $159,000 in fire damage. Everything he owns is destroyed because he make a mistake. Wow. :smack: Is insurance actually going to cover that damage? ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [December 24, 2008, 4:41am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/22 "2008-12-24T04:41:49Z")
> [@Crafter\_Man](#): > > If the connector on the end of the generator cable has \*male \*pins, then it would be dangerous if you started the generator and this connector wasn’t plugged into the house. (The pins in this connector would be exposed!) So the obvious arrangement is to use a cable connector with female sockets and use a connector with male pins for the house. But what happens if you’re not using the generator? Are the pins on the house connector going to be hot via the 240 V at the breaker panel? Yes, unless you use a transfer switch, and the transfer switch is flipped to the right position. It never occurred to me to start the generator with the cord not plugged in, so the outside receptacle would be female. Could be male, though. There is no 240v or any other voltage to the receptacles. Just a box with sockets. The generator plugs into the outside one and an extension cord plugs into the inside one. Just a neater version of drilling a hole in the wall and putting an extension cord through it, or running an extension cord out an open door. Three reasons I haven’t done it: 1) I’m lazy. 2) It’s freezing outside. 3) With my luck I’d find the house wiring with the drill bit. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [December 24, 2008, 7:39am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/23 "2008-12-24T07:39:11Z")
> [@River\_Hippie](#): > > Due to the ice storms (followed by sub zero temps) I’ve been without power since Friday afternoon. I scored a 5700 watt generator yesterday morning and I’m running a 1500 watt space heater and the computer. Also heating with a kerosene heater. Everything else I’m using is battery power. > > My brother in law assures me that the way it’s done is: > A. Turn off main circuit breaker in house. > B. Make a grounded extension cord with male connections at each end. > C. Plug it into an electrical outlet. Powers all outlets in house. > D. Don’t exceed wattage of generator, use bare minimum of lights etc. > > The owners manual specifically says not to do this so I’m currently (heh) following the manual to the letter but BIL’s suggestion would be easier. > > Any input would be appreciated. Do not do it. The item in B is called a suicide cord. If you do not have good wiring experience leave your main panel alone. If you have to ask how to do it, don’t. I do not mean to be hard, but I do not want your family going to a funeral. Also 1500 watts is only 12.5 amps. Watch out for the kerosene heaters inside. They consume O2 and put out Co2 and CO. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [December 24, 2008, 7:50am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/24 "2008-12-24T07:50:30Z")
oops I miss read the wattage. Opening the main and connecting the generator to your panel does not make it safe for the line men. YOur house has three lines. Two hots and a neutral. The breaker only opens the two hots. And your generator has a floating neutral unless you put in a ground rod. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [December 24, 2008, 9:38am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/25 "2008-12-24T09:38:45Z")
> [@Snnipe\_70E](#): > > If you do not have good wiring experience leave your main panel alone. If you have to ask how to do it, don’t. This. Unless you know very well what you are doing don’t even get near the panel. When the professional employees do these things they have detailed safety precautions and procedures which they they are trained to follow scrupulously. And even then there are accidents. With your average home user having little knowledge or discipline (or even common sense) I would say “don’t do it” is the best advice. ---
**Author:** ![Jman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jman/32/4416_2.png) [@Jman](https://boards.straightdope.com/u/Jman)\ **Post date:** [December 24, 2008, 10:18am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/26 "2008-12-24T10:18:33Z")
I can echo the sentiments here: Don’t do it. You start pulling greater than 20A (which is certainly possible since the generator has well beyond that in capacity), and you’re going to start melting your wires and potentially cause a fire. Because you’ll have bypassed the overcurrent protection for these lines, the first sign of a problem will likely be the smell of smoke as your house catches on fire. Your plugs are part of branch circuits, only rated for 20A (most of them), and the wires are too small for any higher amperage. ---
**Author:** ![robcaro](https://avatars.discourse-cdn.com/v4/letter/r/df705f/32.png) [@robcaro](https://boards.straightdope.com/u/robcaro)\ **Post date:** [December 24, 2008, 7:33pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/27 "2008-12-24T19:33:06Z")
What you need is a Generator Transfer Switch. See this link: > **[Generator Transfer Switch Buying and Wiring](https://www.smps.us/transferswitch.html)** > > A guide & advice on buying and hooking up home generator transfer switch: how to choose, wiring diagram, price, sizing. A manual switch for under $150. How to connect a portable genset to your house. Explains a problem with GFCI and grounded neutral.... ---
**Author:** ![River\_Hippie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/river_hippie/32/26_2.png) [@River\_Hippie](https://boards.straightdope.com/u/River_Hippie)\ **Post date:** [December 24, 2008, 11:40pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/28 "2008-12-24T23:40:30Z")
Thanks to all for the good advice! Went out today and got a better extension cord and a battery powered carbon monoxide detector. I won’t be in this house long enough to worry about wiring in a transfer switch but will probably do it at the next place. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [December 25, 2008, 1:52pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/29 "2008-12-25T13:52:13Z")
If you dont want to drill holes in the wall or leave a door or window cracked open you can do this. take a piece of wood a few inches high and make it the right size and shape to lay in the bottom of a window frame. And such that you can bring the window pane back down on it. Cut a hole in the piece of wood for your extension cord to go through. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 25, 2008, 3:39pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/30 "2008-12-25T15:39:34Z")
Even better, drill a hole (or holes) the diameter of the extension cord body, not the head, and then cut the board in half bisecting the hole(s). You can use a 2x4 with the holes drilled 4" long through the 2" face. Lay 1/2 of the board on the sill, lay the extension cords through the ~3/8" diameter troughs, lay the other half of the board on top, then pull the window closed. For sideways-sliding windows the same idea works with theboard vertical, it’s just a little more difficult to install the cords. Hint: duct tape. ---
**Author:** ![Booker57](https://avatars.discourse-cdn.com/v4/letter/b/b9e5f3/32.png) [@Booker57](https://boards.straightdope.com/u/Booker57)\ **Post date:** [December 25, 2008, 4:05pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/31 "2008-12-25T16:05:43Z")
My house has a big hole in the outside wall where the dryer duct goes. Disconnect the duct and run the cords thru the hole. Pack insulation to keep the outside out. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [December 25, 2008, 4:48pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/32 "2008-12-25T16:48:56Z")
I’ve been meaning to ask and it looks like this is the right thread to do so. Ages ago when the internet was young, a buddy of mine was looking to buy a generator. Using a gopher (remember those?) he found a 10-kw unit for about $800 When he showed me the site, I laughed out loud. As a train-nut I recognized the gern instantly: I was off of a refirgerator car. We were guessing they were refurbished ones. He wound up going with something more portable so the site is long lost. In the generator market now, myself I’ve been trying to google it up without siccess. So, can anybody out there direct me to a company selling refurbished railroad generators? ---
**Author:** ![tetranz](https://avatars.discourse-cdn.com/v4/letter/t/a587f6/32.png) [@tetranz](https://boards.straightdope.com/u/tetranz)\ **Post date:** [December 25, 2008, 5:27pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/33 "2008-12-25T17:27:54Z")
Our landlord hooked up a 7 KW 220v generator during the recent long power outage here in NH. He didn’t want his pipes to freeze which also avoided us freezing as an added benefit. He had a friend with him who I think is an electrician who seemed to know what he was doing. Luckily there is an old hot tub out the back that doesn’t work but it has a four wire 220 volt cable and a 50 amp circuit breaker on the switchboard. That was a perfect place to feed the power into and that got the whole house up and running including the oil furnace and water pump etc. Obviously we kept the main switch off but … comments above are correct. It was just one switch position away from very bad things potentially happening. Of course electrocuting someone outside would be the worst thing but I was also a little concerned after we got the grid power back and the generator was still connected with the breaker off that someone might thoughtlessly throw the “hot tub” breaker back on. I shudder to think what would happen to the generator then. Hopefully just a breaker would trip but who knows … It was still somewhat “jury rigged” because during the early part of the outage, you could not buy a four pin plug anywhere so they just jammed the wires into the socket on the generator without a plug. I overheard someone in Burger King talking about feeding a generator into his dryer socket. If I didn’t have expert help, I would just use the generator independent of the house with a good thick extension cord through a window or something that would at least let me run a little heater, lights and microwave etc. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [December 26, 2008, 3:11am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/34 "2008-12-26T03:11:45Z")
I run an extension cord through the window and with a power strip plug the TV, satellite receiver and a floor lamp in. The water pump a unplug from a standard outlet in the pump house and plug into the generator. The Winter we had no power for two weeks wired the gas furnace to a cord and plugged it into the above power strip. ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [December 26, 2008, 4:25am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/35 "2008-12-26T04:25:16Z")
Just an anecdote to liven up the holidays, but my grandfather was a nut about being prepared for the worst, even though he lived in suburban St. Louis. When he built his new house in the 1930’s, he installed an enormous diesel generator in the basement for emergencies. It was big enough to power the entire 2-story house continuously and completely, and it wasn’t hard for him to build since he was an accomplished electrical inventor and had a complete machine shop at his disposal. He never had a real chance to use it in a serious disaster, but he would fire it up about once a month just to make sure everything worked and to scare the neighbors. It sure was a bad-ass machine; the whole house rumbled and rattled until his wife yelled at him to turn it off before the roof fell in. Someday, let me tell you about that roof… 😃 ---
**Author:** ![Jamicat](https://avatars.discourse-cdn.com/v4/letter/j/c67d28/32.png) [@Jamicat](https://boards.straightdope.com/u/Jamicat)\ **Post date:** [December 26, 2008, 6:18am UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/36 "2008-12-26T06:18:59Z")
Is this where we make electrical carvings and switch off the **potatoes**?😕 ---
**Author:** ![River\_Hippie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/river_hippie/32/26_2.png) [@River\_Hippie](https://boards.straightdope.com/u/River_Hippie)\ **Post date:** [December 26, 2008, 3:38pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/37 "2008-12-26T15:38:54Z")
> [@Musicat](#): > > Just an anecdote to liven up the holidays, but my grandfather was a nut about being prepared for the worst, even though he lived in suburban St. Louis. When he built his new house in the 1930’s, he installed an enormous diesel generator in the basement for emergencies. It was big enough to power the entire 2-story house continuously and completely,… > 😃 They have one of those at the place I work. They fire it up about once a month for testing. It’s loud as hell and diesel fumes leak into the building (it’s right next to the loading dock doors that are opened a lot.). Can’t imagine having that in the house! ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [December 26, 2008, 5:21pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/38 "2008-12-26T17:21:49Z")
> [@River\_Hippie](#): > > They have one of those at the place I work. They fire it up about once a month for testing. It’s loud as hell and diesel fumes leak into the building (it’s right next to the loading dock doors that are opened a lot.). Can’t imagine having that in the house! Now you know how my long-suffering grandmother felt. ---
**Author:** ![Uncommon\_Sense](https://avatars.discourse-cdn.com/v4/letter/u/f9ae1b/32.png) [@Uncommon\_Sense](https://boards.straightdope.com/u/Uncommon_Sense)\ **Post date:** [December 26, 2008, 6:31pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/39 "2008-12-26T18:31:08Z")
I had to rig a generator to my house last year during an extended power outage, but I’m an electrician so the following things I did were not out of my _realm_. 1. turned off main breaker, remove meter from its socket, then took off the panel cover 2. disconnected the neutral wire from the panel 3. brought 6500watt generator from the shed to the garage (it’s on wheels now!) 4. made a 75’ cord from 6/3 SO cable with a 30 amp twist lock male connector on one end and plugged that into the 30 amp generator outlet 5. disconnected the 30 amp electric dryer wiring from its breaker in the main panel (have gas dryer, don’t even need the circuit) 6. used the 30 amp breaker (from 5 above) to back-feed the panel with the 75’ cord coming from the generator 7. made sure all connections were tight and safe 8. located the generator close to the overhead garage door 9. opened garage door about 18 inches 10. positioned large box fan so it would cool the generator as it ran and also blow exhaust out of garage 11. start generator and enjoy the sweet, delicious electrons that flowed throughout my humble abode 12. power came back on ten minutes later (jk! it was more like 12 hours later.) ---
**Author:** ![ntcrawler](https://avatars.discourse-cdn.com/v4/letter/n/34f0e0/32.png) [@ntcrawler](https://boards.straightdope.com/u/ntcrawler)\ **Post date:** [December 26, 2008, 6:44pm UTC](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482/40 "2008-12-26T18:44:51Z")
When using a transfer switch or killing the main breakers, how do you find out then when utility power has been restored? [Previous page](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482.md?page=1) [Next page](https://boards.straightdope.com/t/portable-generator-wired-into-home-wiring-yes-or-no/478482.md?page=3)