So you've been hit by a hurricane, you've made your way to a shelter, and you've pulled this web page up on your cell phone (all in old-fashioned HTML, by the way). When you return home, you plan to fire up a generator, back-feed into the drier outlet, and light the house up. Right? Well, if you don't know more than that, you could easily electrocute yourself, electrocute a utility worker, blow out your generator, or set your house on fire. In fact even if you think you've got everything dried out and working right, and you've got your electric service back on, your house could catch fire in the middle of the night a month later. There are things you need to know before you pull the starter cord or flip a breaker, and there aren't many people who will tell them to you. As a lifelong electronics enthusiast/geek, perhaps I can offer a few words of caution.
First, a few words about myself: I am not a qualified electrician and have no licenses or certifications that qualify me to give anybody any advice about household wiring, emergency power, or disaster relief. In this discussion, I will be discussing what I consider, based on my own personal opinions, to be unsafe practices and potential hazards. Do not construe any of what I say as any assurance that any particular practice is "safe." Hooking up to emergency power is rarely, if ever, a completely safe practice, at least in a home that has been soaked with salt water. You will need to check all of my advice with licensed electricians who are knowledgeable about local electrical codes. If you act on any of my advice without consulting with a local, licensed electrician, I cannot be responsible for any adverse consequences (including, but not limited to, electrocution, fire, or death) that may result. If an electrician does not agree with my advice, then my advice should be considered incorrect and invalid.
My only qualifications are that I've been through hurricanes and floods myself, and I dealt with emergency power issues successfully (in my opinion), while a few other homes in the area caught fire upon restoration of electric service. After Isabel (2003) we had no help from Mr. Bush's FEMA or National Guard until almost a week after we returned to our flooded homes. Therefore I had to figure all this stuff out on my own. Fortunately I knew something about electronics and had done a lot of my own household wiring work. Thus far, I've never had anything blow up or short out, and nobody (including any building inspector) has ever complained about the quality of my work. With all that in mind, let's move forward....
The first thing to consider in such a situation is how you should prepare your home for the power outage before the storm hits. Most people don't think that far ahead. Chances are that you didn't. To be perfectly candid, neither did I. When the big storm hits, there will be several factors to consider. First, there will be flickering power and brownouts just before the power goes down. When the power flickers on and off, any running compressors (e.g. in an air conditioner, heat pump, refrigerator, or freezer) may quickly cycle on and off with the power. This is called short-cycling, and it can very easily burn out the compressor motor. This happens because of the compressor's inability to compress liquid freon (rather than gaseous freon) that can momentarily surge to the intake side. A locked down compressor motor draws a very large amperage and generates enormous heat. If the motor has no thermal protection switch (which many don't), it will burn out. This is often prevented with a startup delay in the control circuitry, but generally not in older or cheaper air conditioners or heat pumps, and almost never (?) in refrigerators and freezers.
Even if the compressor doesn't short-cycle before the power failure, it could still burn out from brownout conditions (low supply voltage). The risk is all the greater, however, for electronic circuitry in the household (including the logic circuitry in your HVAC systems, of course). The only exception might be devices that you place on conditioned power and/or battery backup. These might include security systems, which usually include large backup batteries, and any other monitoring equipment you might place on a UPS. Be advised that a surge protector will not protect your equipment from brownouts.
With these things in mind, it is important to decide which devices, if any, can be and need to be running up to the point of power failure. A security system might be one such device. Off hand, I can think of no other. The need for such systems must be balanced against the dangers of having any such system running off of electric power until the power fails. Not the least of these dangers is that salt-water flooding may occur just prior to electrical failure, particularly if yours is the lowest lying electrical system fed from your drop transformer. Obviously water and electricity don't mix, particularly saltwater. More on that later...
Once you have decided whether you really need anything running in your house, you need to identify which circuit breaker feeds power to that device. That should be the only breaker, other than the main breaker, that you have turned on. If you decide that you don't need anything running that badly, which I think would be a wise decision, you should plan to cut off the main breaker just before evacuating. In fact it won't hurt to flip off all the breakers if you don't know which one is the main. Also, because of the possibility of lightning strikes, and downed electric lines crossing downed cable and telephone lines, it's really not a bad idea to disconnect both the telephone and cable too, provided they aren't needed for a security system. (But will Brinks security "really" be rolling out to your house in 140 mph wind to check out an alarm that went off, or will they just assume a tree probably fell through your roof, tripping the motion detector?)
You'll of course need to make minimal preparations for shutting down power. For instance, you will need to keep your refrigerators and freezers cold. As long as they don't get flooded or opened, they may be OK for as long as it takes to evacuate, weather the storm, and promptly return. You will know by measuring the temperature inside. To help your refrigerators and freezers stay cold longer, prepare lots of ice in drip-proof containers, such as partially filled plastic Coke bottles. Move much of this ice to the lower compartment just before shutting down power. Later, the melted ice can be used for drinking water. For the time being, it will help keep both compartments cold. Of course if the refrigerator gets flooded, throw out any contents, as they will be contaminated with things you don't even want to know about!
If you have the room when you evacuate, remember to take your generator with you. If you don't have room, move the generator to a secure location (e.g. in the house) above the maximum anticipated storm surge, and tarp it. It sounds really dumb, but I saw a lot of soggy, rusty generators out on the curb-side in the wake of Isabel, just because people didn't think their garage, elevation 2'7", would get flooded. Listen to the predictions, and believe them. Keep your generator safe. Also keep your tools safe. This equipment will make all the difference in how well you are able to survive the cleanup. Incidentally, if you are traveling into a hurricane-ravaged area to help friends or family, don't just bring one generator. Bring two or three. Someone will buy the excess off of you with much gratitude.
All of this probably catches you up with where you are right now. You didn't do half of this stuff? Well, don't worry about it too much. You took a lot of unneccessary risk, and you might have suffered a bit more damage than necessary, but you have bigger worries. As you weave down your street between downed trees and power lines and satisfy yourself that your home is still standing, sort of, you've got a lot of work ahead. Your first job, if you haven't already done it, is to switch off all the breakers in your electric panel. If your home has been flooded, do this very cautiously, checking first that the power is really out, that your neighbors on the same drop transformer haven't fired up a huge generator (and perhaps hooked it up the wrong way). In any questionable situation, tie a rope around your waist, and have a friend ready to pull you away if you are electrocuted. Wear rubber boots and dishwashing gloves.
Now that you've removed most of the electrocution hazard from your home, you need to determine whether water has gotten into your electrical wiring. If your wiring (including in your basement or crawl space!) was spared from water exposure, you can breathe a sigh of relief and skip to the parts about powering up your generator. If your wiring was soaked, you might have trouble. First, you have to understand water and electricity. Contrary to popular belief, water does not conduct electricity by itself. It requires a bit of salt content. Pure rain water from high in the Rocky Mountains, collected before it hits the ground, is probably pretty salt-free and therefore not very conductive. As soon as this water hits the ground, it starts picking up salts and starts to become conductive. Rain water along a coastline almost certainly has some salt content even under the best of circumstances, as it typically falls through the same fine salt spray/mist that is responsible for turning everything to rust. Rain from a hurricane can have even more salt content, as water spouts can suck sea water into the air. Salty flood water of course has the greatest salt content.
What are the dangers from these different sorts of water? If the water has even the slightest salt content to it, it can conduct enough electricity to electrocute a person. In fact if a person's bodily fluids are saltier than the surrounding water, the path of least resistance for the electricity would be right through the person's body, rather than through the surrounding water. In other words, be very careful around electricity and water!
Aside from that, the water leaves a salt residue when it dries. This residue actually draws trace amounts of moisture from the atmosphere and can be conductive even when believed to be "dry." (Salt can't conduct electricity by itself either. It requires at least some moisture.) Ordinarily, rain water would be unlikely to leave any salt residue on or near the electrical wiring, but if there is any salt residue at all, especially from saltwater flooding, there is a potential hazard that must be dealt with before power can safely be restored to your home. Most immediately, this is an electrocution hazard. However, in the longer term, weak electrical "leakage" around exposed wires can cause rapid corrosion of the wiring, which can result in the narrowing of conductive paths and partial failure of electrical connections, which can then result in dangerous overheating and/or arcing. In the aftermath of Isabel, which hit the Hampton Roads, VA area with about 6 ft of storm surge, there were at least a few homes that caught fire from electrical failures in our immediate area. I anticipate the electrical wiring in most of the remaining "dried out" homes will rapidly degrade over the coming years and would not be what I would consider safe.
So your wiring is saltwater soaked? You have my sympathies. I've been there, done that, and it wasn't any fun! You have a choice to make, probably assisted with the expert advice of a local, licensed electrician who may tell you I'm fully of organic fertilizer. You can choose to be an ostrich or a beaver. An ostrich of course buries its head in the sand (not really, but...) and hopes that the danger isn't really that great. A beaver accepts the reality of the situation, swallows hard, and busily gets to work. It's a long, hard slog.
The first step is to wash down all the wiring. I would recommend this simple precaution even for the ostriches who are reading this. it's really quite simple. Just hook up a garden hose, and wash away the salt. This is good not only for your wiring, but also for all your building materials. Few things will last very long when crusted in salt residue. (Remember all those nails that hold together your house, by the way!) Also, just think of all the chemicals that were in your garage. Where did they go? They went the same place all your neighbors' chemicals went -- all over the place. Paints, pesticides, oils, sewage, antifreeze, and other lovely things make up that orange sludge that's thinly coated over your walls. Remember, if it's already been flooded, it's not going to get much wetter. Spray it down!
Next, let the areas you washed dry. You may wish to use electric box fans to speed this process. For that, you will need generator power. At this point, DO NOT back-feed your generator into the household electrical system. Rather, plug your fans directly into the generator, using extension cords. Keep the cords away from the water. When the wiring looks dry, remember that it isn't "really" dry. Depending on the type of wiring, you probably still have saltwater pooled inside the wires. Don't worry about that for now. The main objective is to remove electrocution hazards to people standing near electrical wiring. while all the wiring is drying, prepare for the next step by unplugging everything in the household. If something cannot be unplugged, turn it off.
From this point, you can either get an electrician (good luck!), or you can be your own electrician. I implore you to hire a licensed technician, because you might otherwise get yourself killed. However, I would watch the electrician very carefully and see if he (or she!) does any of what I did. Here's what I did:
First, I opened the breaker panel, exposing all of the wiring. The flood water hadn't reached the breaker panel, but if it had, I would have pulled the electrical meter (a more up-stream cutoff), washed out the breaker box with a garden hose, let the box dry thoroughly, and replace all of the breakers (which could not be relied upon anymore). With an electrical meter, circuit by circuit, I tested the conductivity between the neutral pole (where all the white and bare wires are connected) and the screw terminals where the wires connect to the breakers. I used a multimeter with a 2 megaohm scale, but I would have used an even more sensitive one if available at the time. Why measure megaohms? Well, electrical paths through human bodies are on that scale, so that's really all the conductivity it takes to electrocute a person. In the course of my measurements, I put "OK" stickers on the breakers for the circuits that checked with no measurable conductivity. Sometimes I would come across a reading on the order of a couple of ohms or so. That generally indicated a light switch had been left on. After an often protracted search, the culprit could be found, and I could re-check. There were a few circuits that had conductivities (resistances, actually) of 2000 or 3000 ohms, for which no obvious culprits could be identified. I labeled these as probable "leaky" circuits. To prevent their being accidentally energized, I pulled those breakers from the panel and left them hanging.
The "OK" circuits identified in the previous paragraph were not really OK, in the sense of any permanence. The flooded home was built in the late 1950's and used mostly braided electrical wiring -- the black, slightly tarry stuff with the silver paint on it. Of course no braid is waterproof, and if there were any deterioration in or damage to the underlying insulation, salt water would have reached bare copper. Some of the wiring was modern interior Romex, but even this type wiring is not waterproof, and saltwater can get trapped between the outer jacket and the electrical wires. I think my choice of wiring in a frequent hurricane zone would be exterior Romex, even for interior wiring. That is because the three wires (i.e. hot, neutral, and ground) are each contained within their own separate sleeves. Unfortunately this grade off wiring costs more, is slightly harder to use, and probably isn't considered worth the extra expense. (Almost certainly, your home is not wired with exterior Romex.)
The twenty dollar question was, "How does one remove salt water from the interior of one's electrical wiring." The disappointing answer is that it would be impossible. Once saltwater enters, it stays. The water might evaporate, mostly, over a period of months or years, but the moist, conductive salt scum would remain behind. We were fortunate, in that water rose to the middle of the floor joists but didn't climb into the floor and walls. All of this wiring was accessible from the crawl space. Our decision was to install dozens of junction boxes where the electrical wiring rose into the walls, and to replace the wiring running on the underside of the joists wire segment by wire segment. At that time, we were dealing with an unknown risk, but we became increasingly smug about our decision in the following weeks everytime we heard the fire department racing to yet another electrical fire.
Further disclaimer: Setting up emergency power can be a very dangerous if done improperly. Only a qualified, licensed, local electrician, familiar with local electrical codes, can guarantee a safe generator power installation. Of course if the wiring has become soaked in saltwater, all bets are off. If you want to be completely safe, I advise that you follow the instructions that came with the generator, which probably instruct you not to back-feed power through your household electric circuits. However, I also recognize that some people must consider other safety factors and might be interested in my experiences on this subject. This was our situation:
In our situation we were caring for an elderly woman with Alzheimer's disease. Being in a disaster situation was already very disorienting to her, and to have her house operate in unfamiliar ways could have been very disruptive, if not potentially dangerous. I decided that although the saltwater soaked electrical wiring posed a long-term safety risk, it posed no short-term risk, so long as I could not measure any cross-conductances on the circuits I was energizing (see above). Furthermore, any risk would have been to myself (working in the crawl space area) and not to any occupants of the house (who were not in a saltwater-soaked environment).
I sought first to establish basic electric service, by energizing the lower amperage circuits (15 and 20A each) for lights, wall outlets, etc. I planned to do this by back-feeding the breaker panel through one of the heavier 220V (double) breakers. Fortunately there was a nice 40A double breaker that was unused. This was more than adequate for the application, since the generator had a 5500W maximum output at 220V, meaning a maximum output current of 5500/220=25A. The amperage rating of the breaker was irrelevant, as long as it was greater than 25A. Overload protection would be from the generator's internal breakers. I decided to use 10 ga, three-conductor (plus ground) cabling, as 10 ga wire is rated at 30A for household use. For a less powerful unit generating less than 20A, I might have chosen 12 ga wiring, which is rated at 20A. Before starting the generator (!!), connected the black wire from one hot pole of the generator to one side of the double breaker, the red wire from the other hot pole of the generator to the other side of the double breaker, the white wire from the neutral pole of the generator to the neutral/ground strip of the breaker panel, and the bare ground wire from the ground of the generator to the neutral/ground strip of the breaker panel.
Before firing up the generator, I double checked that all breakers were in the off position, including ESPECIALLY the main breaker. Why the main breaker? There are several reasons. First, if you fire up your household electrical system with the main breaker on, you'll be trying to backfeed power to your entire municipality. If your local power plant doesn't have the wattage to do it, your little Honda generator won't either! But assuming your neighbors have their mains disconnected, the drop transformer is blown, and there are no shorts, in your wiring to the pole, you might not have to light up the whole city to get your house running. However, when the utility worker comes to your neighborhood to restore power to your block, it could be your little Honda generator that electrocutes him. But let's say he avoids that unnecessary hazard, throws the switches, and lights up your block anyway. Then that big power plant and your little Honda generator will be fighting against each other viciously. Guess which generator is going to lose!
You also need to double check that nothing is plugged in that was soaked with salt water. Very important! That especially means your garage refrigerators! If your furnace or water heater was soaked, make sure that you do not energize those lines. In fact it might be a good idea to pull those breakers from the breaker panel, to make sure it doesn't happen by accident.
OK, now ready for the big moment, I pulled the cord, and my little generator broke the silence, whirring into action. As it was a new generator, I let it run for a few minutes before putting it under any electrical load. The first breaker I turned on was the double 40A breaker I was using to back-feed the power. That energized the panel. Then one by one, with occupants out of the house, I energized all of the lower amperage (15 and 20A) breakers. Before doing anything else, I inspected carefully to find any evidence of smoke, or steam coming from any of the wiring. When I didn't find any, I turned on lights, one by one, and ensured that they were working properly. Then I used an electrical tester to determine that the wall sockets were good. At that point, I happily told everyone they could go back inside and enjoy the use of any electrical devices that didn't draw huge amounts of power. On the forbidden list were heating appliances like toasters, electric skillets, crock pots, coffee makers, space heaters (not necessary in that heat!!), and hair dryers.
Next, I plugged in the indoor refrigerator, which had not been flooded with saltwater. It of course ran perfectly well. I opened it up and found that it was still cold after 2 days, although the items in the freezer section had thawed somewhat.
With basic power restored, we turned to the awful task of sorting through what was left of the garage. The water had picked everything up, churned it around, dumped it, and left, but only after having left a lovely coating of orange toxic sludge on everything.
REFRIGERATORS: If you're like us, you have a refrigerator in your garage. The compressor is sealed, so it will be OK. However, you're going to have to clean up some of the salt water. Your first step will be to open up the compressor relay housing on the side of the compressor. Take note of what wires are plugged in where. Unplug them. Pull the relay off of the side of the compressor. (The compressor plugs into it.) Drop the relay into a bucket of clean water. You may also have a condensor fan down underneath your frig. If the water got into the motor, you'll need to clean it out too. Here's the bad news: If your frig was running at the time it got soaked, your little motor is probably gone. To test it, unplug it, and test the resistance across the two terminals. If you have a very low resistance, then you're in luck. Now drop the motor into the bucket of water. Try to give the relay and the motor several good dunkings, change the water, keep soaking, etc. If possible, disassemble the motor somewhat, so that you can get water in and out of it. Once you've gotten the bulk of the salt out, then do a couple of last rinses with distilled water. Finally, bake the parts in a toaster oven at the lowest temperature setting for a couple of hours, probably not over 200 deg F. Note: this will put a huge load on your generator. However, it will be essential for restoring your refrigerator. Other alternatives involve constructing a solar oven. Finally, while all this is going on, take a garden hose, and wash out the mechanicals of the frig. After the relay and the condensor fan motor dry, reassemble/reinstall. Plug all the wires back in, and you should have a working frig again. If you lost your condensor fan motor, you can get by on a temporary basis by attaching the wires to a little tabletop fan and insulating them with electrical tape. Point the fan so that it blows across the coil when the compressor runs. You can get a replacement fan motor later.
ELECTRIC WATER HEATERS: If your water heater got soaked, it's probably going to need to be replaced. The hazard is that the salt water will rust it out. However, it will get you by for the time being. If it's insulated with fiberglass, find a hole where you can run lots of fresh water through the fiberglass and out the bottom. Clear away any insulation from around the heating elements and wiring, and make sure that's all washed down with fresh water. Let it dry. Now here's the tricky part that not many people will know. (Please tell them about it!) You can run your water heater off of your generator if you don't get to hoggish about it. To do this, remove the white wire from its circuit breaker, and instead screw it into the neutral terminal in the breaker panel (where lots of bare wires and white wires are screwed in). Your water heater will now run off of 110V, instead of 220V. As a result, it will only draw a quarter of its rated wattage. It will heat slowly, but at least it won't kill your generator.
Good luck with your situation! I know it's rough. Once you get your household up and running again, remember your neighbors. I mention this because none of us checked on our neighbors after Isabelle. One man down the street who was in a desperate situation committed suicide. I think things would have been much different if a neighbor had knocked on his door and asked, "How can I help?" Also the elderly woman next door to us lived without a wall between her house and garage and went without heat well into the winter, because an unscrupulous HVAC contractor ripped her house apart and walked away. As soon as we learned this, we stapled her up a temporary wall out of cardboard and plastic and fixed her up with some temporary heat. Never assume your neighbors are OK. They won't ask you for help, even when they're in crisis.
Also learn to pool your resources. Pull out a BBQ grill, and invite people to cook up the meat from their inoperable freezers. Help people to fix their freezers (see above). Connect a garden hose to the drain spigot on your water heater, and run it to a tent in the front yard. People need hot showers. Run extension cords to the refrigerators in your neighbors' houses if you have extra power. Go from door to door and ask not just what people need, but what they can offer. Identify your carpenters, electricians, HVAC technicians, chainsaw owners, etc. Find ways to band together. Our biggest failing in this neighborhood was that we didn't pull together, and we lost a neighbor because of it. Don't let it happen in your neighborhood!
AGAIN, GOOD LUCK!