Generator connections for us cheapskates

[Smartass]

Last week, the power went out for the first time since I got my generator. It took about 80 minutes to get it hooked up and running. I could have done it in 5 minutes if not for some special problems with my house wiring, as well as two unforseen problems. The original plan (for a properly wired house) is as follows:

Step #1 By far, the most important step is to disconnect the breaker panel from the external power grid. Ordinarily, you just switch off the main disconnect in the breaker panel. (Automated systems, costing upwards of $1000, do this automatically before connecting the generator.)

Step #2 Plug the generator output cable into the nearest 240 vac outlet. This requires a male-to-male cable with the appropriate connectors. I'm not sure if you can buy one like this. It's not idiot proof, and it can electrocute you if you don't know what you're doing.

Step #3 Plug the cable into the generator. Don't run the generator with the house end of the cable unplugged, as this will make the exposed prongs of the male connector hot.

Step #3 Start the generator.

Ordinarily, that's all there is to it. This arrangement should provide power to all of your house wiring.

Note that the generator output will be limited by the circuit breaker on the circuit you plug it into. If the generator's own circuit breaker has a lower rating than the circuit you plug into, then you can use the full power rating of the generator. Be careful what appliances you use. If you have a 15 amp generator, you should turn off the circuit breakers for the electric heating and the water heater; only use one burner on the electric range. Don't use the range and the microwave at the same time.

My situation is a bit more complicated. The place I'm renting has no main disconnect (a big code violation), so my step #1 is to switch off all 6 of the 220 vac breakers, one of which is connected to a bunch of 120 vac breakers.

The original plan was to plug the generator into the drier outlet and connect the drier circuit to other circuits via jumper wires in the breaker panel. So I proceeded with: Step #2 Install the necessary jumper wires. My 15 amp generator can't handle the baseboard heaters or the water heater, so my jumpers only deliver power to the range and the 120 vac circuit breakers.

Step #3 Plug the generator cord into the drier outlet. I had kluged together a 240 vac male-to-male power cord to plug into the drier outlet, but the generator end had the wrong plug on it. So I unplugged from the drier outlet and removed the jumpers in the breaker pane.

Plan B: Use the 120 vac output of the generator via the nearest outdoor outlet.

New Step #2 Connect a single jumper wire from the phase A 120 vac circuit breakers to the the phase B 120 vac circuit breakers.

New Step #3 I also had a 120 vac male-to-male cord which I connected to the nearest 120 vac outlet.

New Step #4 Connect the 120 vac male-to-male cord to the generator.

New Step #5 Start the generator. Oooops! The pull cord snapped on the first pull.

New Step #5 Relplace the pull cord outside in the rain in a 40 mph wind at night.

New Step #6 Start the generator.

That worked just fine! I had power on all my 120 vac circuits. And then the main power came back on, but I didn't know it because I wasn't connected to it.

New plan to get ready for next time: #1 Put the correct connector on the

240 vac power cord. #2 Prepare some sort of alarm (perhaps a radio) to be wired to one phase of the heater circuit breaker (which will be the only circuit still connected to the external grid).

------------------------------------- Retired tech.\\//.

------------------------------------- Retired tech.\\//.

[aemeijers]

Smartass wrote: (bad advice snipped)

Are you simply trolling or something? What you propose is dangerous and often illegal. This very same topic comes up on here every couple of months, and the method you propose always gets smacked down. There is a reason they don't sell double-male-ended cords. They don't wanna get sued when a spouse, neighbor, or power company guy gets electrocuted. Sure, you know what is going on. But what if you are injured, dead, or out scavenging supplies?

Either do it the right way, with a transfer switch, or put pigtails on your critical appliances that are hardwired, and run cords through the window. Or do without. Those are your 3 safe options.

-- aem sends...

[Harry L]

[snip]

"Disclaimer: No linemen were killed in the making of this post"

[snip]

[gfretwell]

"Farewell and adieu to you, Spanish Ladies"

[Jules]

fair ^^

Now I'm going to be humming that to myself for the rest of the evening... :-)

[bud--]

6 service disconnects in a "split bus" panel did not used to be a violation to install. The existing panel is not a code violation.

I agree with aemeijers.

Note that the OP comes from the succo company - what a surprise.

[mkirsch1]

Hang on while I get some popcorn. This should be good.

[SMS]

OMG, please don't try this!

[SMS]

It's not just that, it's putting the entire load of the house backward through a 240V outlet, and expecting the wiring and the breaker to handle the whole house current.

[jamesgangnc]

It's not a problem to backfeed a generator through a double breaker. A 30 amp dryer breaker can handle anything up to 7kw. I agree, it's dangerous and illegal. It is very critical that you disconnect the main first. There is a slightly more expensive way to do this using a pair of breakers in the top position with a mechanical lockout between them and the main. There is a company that sells such lockouts. It's just a sliding thing that requires the main be off before the top set of breakers can be on and vis-versa. Would not work for the op since he has 6 mains.

[Smartass]

I addressed that issue in my original post. The "entire load of the house" is only those appliances that are connected at a given time. I am not expecting the generator to heat the house or the hot water; those breakers are off, and I am not running jumpers to them from the drier circuit. I keep a pot of hot water on top of the kerosene space heater and use it for everything from coffee to a sponge bath. I am using only one element of the range, and not at the same time as the 800 Watt microwave.

------------------------------------- Retired tech.\\//.

[Smartass]

A valid point. If I did not live alone, I'd either take anyone who can't be trusted to follow instructions with me, or else I'd leave them without electricity until I return. If they REALLY can't be trusted, I'd take the male-to-male power cord with me.

------------------------------------- Retired tech.\\//.

[Art Todesco]

Try this, someone here pointed it out the last 6 times this topic surfaced.

no one has addressed this. If you were stupid enough to leave the panel connected to the power grid and you connected the genset, wouldn't the engine just die due to the huge load? Unless, of course, you have a huge generator.

[Michael Dobony]

Yes they do. I have seen them in the big box stores and farm supply stores. They are called generator hookup cables.

They don't wanna get

[anniemalover]

What happens when you start up the generator without disconnecting from the external grid depends on who else is connected and how. In my case, there are perhaps 5 other homes on the same transformer, and several transformers on my dead end street. There is a 17 kv fuse where the power comes off the trunk line, and the substation is 1/4 mile from that fuse.

Worst case: If the 17 kv fuse happens to be blown or disconnected, and if all the other homes on my street have shut off their service panels, then my generator output would be stepped up by the transformer to supply 17 kv to the rest of the street. With 15 amps

240 vac from the generator, you could get up to .2 amp at 17 kv. Any lineman working on th 17 kv line at the time would get quite a jolt and perhaps be electrocuted.

Most likely case: My neighbors would be placing such a load on the transformer that my generator's 15 amp breaker would trip instantly without damaging anything. I'm not sure if the motor would continue running after the circuit breaker is tripped; it depends on how it is wired internally.

Another concern is what happens when power is restored on the external grid. Obviously, I need to remove my ad hoc jumper wires in the panel, but I wouldn't have those if the panel were up to code in the first place. Second, if the generator is connected when power is restored, it will attempt to maintain its own voltage. If the output voltage of the power grid is even a fraction of a volt lower than the generator's output, the generator's breaker will trip instantly. I'm not sure what would happen if the grid voltage is higher; it might take a few seconds for the breaker to trip, depending on how the generator is wired internally.

[anniemalover]

I forgot to mention that I, anniemalover, am also know as Smartass. I took Stormin Mormon's advice and avoided going thru the Stucco site, this time.