For long term failures, I'd want to save my gasoline for water, and of course, for DC on the INTERNET :)
This is a discussion on Please Share Your Wisdom On Portable Generators within the Off Topic & Humor Discussion forums, part of the The Back Porch category; Here's my opinion on the generators. I work for the power company (username: poleclimber). Anyway, if you intend to use a standby generator do everyone ...
Here's my opinion on the generators. I work for the power company (username: poleclimber). Anyway, if you intend to use a standby generator do everyone a favor and spend the money having an electrician install a transfer switch. There are a few things that can happen if you hook your generator up improperly, the most important one is that you can KILL your local electric worker.
The transformer you have feeding your house will work very efficiently in both directions, it doesn't care. It can take the high voltage and 'transform' it to your 120/240 you use in your house, however, if you put 120/240 back into it during an outage it really doesn't mind, it will work backwards and produce high voltage and feed the main line. Normally this would overload your generator and you would immediately know something is wrong. Sometimes it works just fine. I was on one trouble call where a farmer was feeding 2 or 3 of the neighbors, the neighbors didn't know anything was wrong, they just thought the power was back on and the nice farmer with the generator couldn't figure out why he's using so much diesel... Rare, but it can happen.
Second scenario, you actually backfeed the main line with high voltage and for some reason your generator actually holds. Maybe your line is isolated by whatever caused the outage. If I'm doing my job according to policy, the first thing I am going to do is ground the line. I am not going to know your generator is feeding it. I may or may not see a large arc when I install the ground but your generator is going to see it for sure. Dead short = lots of load = burned up generator.
The last major ice storm we had left some people without power for 14 days. I found several generators hooked up with techniques discussed above which are not legal. After I have been working 14 days straight I get very hard to get along with, especially when your doing something that could kill me or one of my co-workers. I had several people who I just disconnected, go ahead and run your generator without a switch if you want to, your power isn't going to come back any time soon if it's discovered by the utility. We actually document who has been caught with improper generator connections, you earn a spot in our system map. When your line goes out the first thing we do is disconnect your transformer. You WILL be the last one reconnected, maybe a full day after the neighbors are back on.
Sorry for the rant! I just have some strong feelings on the topic. Do the right thing, get a transfer switch and hook your generator up properly.
For long term failures, I'd want to save my gasoline for water, and of course, for DC on the INTERNET :)
Liberty, Property, or Death - Jonathan Gardner's powder horn inscription 1776
Tu ne cede malis, sed contra audentior ito.
("Do not give in to evil but proceed ever more boldly against it.")
-Virgil, Aeneid, vi, 95
Among many past hats/helmets I've worn, being a retired fire chief of a major midwestern city and a wireless radio communications system & site engineer have given me quite a bit of experience with all types of emergency power generators. This thread's premise was questioning "portable" generators which imply something carried in the back of a pickup for running power tools in the field to something similar carried on a fire engine to run the "jaws of life" for occupant extracation from a wrecked vehicle. While "portable" generators can be used for emergency home power (if you know what you're doing and can hook them up properly), most home emergency power would be classed in the "fixed" generator class.
Regardless of whether your initial question was regarding only the "portable" type generator for mobile use in the field or for emergency home power that's more inline with the "fixed" application, figuring out just what particular fuel type is best will depend on the intended application; however, figuring the particular generating capacity (in kilowatts / KW) you'll need for any particular application is all the same whether a generator is "portable" or "fixed" in nature.
If you're looking for a "portable" that's going to be frequently used, then a gasoline powered model is best and least expensive. If you're only going to use the generator a few times each year, then a diesel powered model will be more reliable since gasoline will quickly stratify in the tank (even using Stabil) and evaporate out of the carburator to leave muck and varnish the will generally keep the generator from starting when you need it. Diesel powered models are all fuel-injected and have little problem with evaporation or fuel stratification if they're cranked up and ran a couple of times per year; but the downside of diesel is the fuel-gelling in very cold weather and long-term storage will eventually introduce water into the fuel tank from condensation that happens via "breathing" of air moving in and out of the tank on a daily basis as it warms during the day and cools at night. If you're looking for a generator that might sit for a year or so without being started (and providing you have a "floating charger" constantly hooked to the starting battery if it's not a pull-start), then you should only consider a natural gas/propane powered unit because there will be no fuel degradation or moisture contamination over long periods of time, and she'll bust right off when needed. Most propane/gas powered engines can use either one of the two; so a "portable" unit can be easily powered by a little 6-gallon gas grill tank, and a "fixed" unit can be hooked to a natural gas line and incorporate a pressure-actived switchover valve that will let the generator run on an auxiliary propane tank in the event of low or zero pressure on the natural gas line.
Once you decide on the fuel type that's best for your intended application, the biggest decision will be on the generator's output capacity that you desire. Trust me, the world is full of sad people selling generators that ended up spending a lot of money on a generator that proved to be far too small in output capacity because they weren't aware of how to figure what they really needed for the ambient (and starting) load requirements of the desired usage. Generator capacity is a no-brainer because they are all listed in actual output wattage (power) in either actual wattage (e.g. 5,000) or in kilowatts (e.g. 5KW).
The difficult part is trying to figure out the total amount of wattage you'll need for all the stuff you want to run because many power tools and appliances are rated differently. Some actually give you the particular wattage (in watts) necessary to run the device, but others are confusing by listing "EI", "IE", or "EIU" which is the same as watts (Power/Watts = E/Voltage x I/Amps). Since many power tools boast their strength by only relating their current draw (e.g. 5-amp, 14-amp, etc.), you must figure the actual wattage needed by multiplying the rated amps by the voltage the tool runs on (e.g. 14-amps @ 120-volts = 14 x 120 = 1,680 watts or 1.7KW).
When figuring out the capacity of the generator needed for a particular application, most people simply total up the wattage of everything they plan to have powered by the generator at any given time. This is fine if you're only looking at running most power tools, light bulbs, and other items which don't have to start up under a physical load of any type. HOWEVER, the big mistake most commonly made in figuring the capacity needed is in regard to powering any item or appliance that must start up under a physical load (e.g. any refrigeration compressor, pump, or air compressor) because, in spite of their "rated" current draw or running wattage listed on the tag, all of those items will require at least TWICE (and more often 3-times) the rated amps (or watts) to start up. Ever notice that your refrigerator, air conditioner, air compressor, or well pump always causes all the lights in the house to dim for a second when they start up? That's from the tremendous amount of current (amps) they draw during startup that literally sucks down the voltage supply to the house.
So, if you're looking to run just your 1,200 watt refrigerator with an emergency generator, it's most likely going to take a 5,000 watt (5KW) just to get it started up; and if you have more than one of such devices, you'll have to manually plug them in one at a time to keep all of them from overloading the generator while trying to startup at once. If the generator doesn't have enough capacity for said startup, it will lug down, drop its output voltage, and end up letting all the smoke out of the generator AND your refrigerator's compressor motor.
If you ever consider a "fixed" generator that will power your entire house during a power failure (via the "power transfer contactor" mentioned by our leaned electrician), then you're moving into the world of big bucks with a generator having a small oilfield engine powering it. Most homes have 200amp service @ 240VAC; so putting the calculator to work with 200 x 240, you'll need a big honkin' 50KW baby to meet the challenge and at least a 1,000 gallon propane tank to keep it running for any reasonable length of time. Good generating
Well written post Eaglebeak, lots of good information and easy to understand
1. Using a "small" generator through a transfer switch will require the homeowner to initially turn off the breakers to the unnecessary circuits/appliances that aren't absolutely necessary. IOW the little generator can't run the whole house, so parts of the house have to be disabled so the generator doesn't get overloaded.
2. The small portable generators typically should be used with extension cords (and not too many) and those extension cords are used to go directly to the appliances that are needed. If no generator power is fed through the wiring of the house, then it would not be possible to back-feed to endanger any lineman. If the homeowner is absolutely diligent in feeding generator power to dedicated appliances there should be no problem. An extension cord running directly from the generator to the refrigerator cannot cause a safety issue.
Last edited by ppkheat; October 18th, 2011 at 07:53 AM.
Gain a 2A vote, take a fence-sitter shooting.
I am learning a lot here. Much thanks to all who are participating in this thread. Your knowledge base on this topic is amazing to me.
My intention is to do it right the first time.
In the past, during major outage events, we have had area electricians selling "custom made" cords with two male ends so you could easily plug one end into the generator and the other into an outlet in the house, typically the dryer outlet. This is not the type of cord we are talking about A good way to look at it, if you are going to try to energize the wiring in the walls of your house, get a transfer switch.
Again, thanks ppk for pointing out the simplest/least expensive option, my mind was clouded from my rant!
I am glad that I have found this thread here because I need a portable generator and I have no idea which one I should choose. Generator rentals were my first choice until now but I decided that I need my own one and due to this I am looking for a good offer. I am pretty sure that this thread will help me to choose the right portable generator for me.
I like the way you think, QKshooter.
Regardless of what unit that you choose, another key factor is maintenance.
In a previous IT consulting career, we'd occasionally test backup systems by throwing the main power breaker to see if the generators came online. In reality they had about a 50% failure rate (not good, especially for hospitals).
Like any other piece of machinery, lack of use is its worse enemy. Seals dry out, break and open up. Critters and bugs find their way into places where they shouldn't be. I'd recommend committing to a quarterly or monthly maintenance plan.
'Clinging to my guns and religion
don't buy a cheep one
buy the way I have an inverter (4000 w) it is hooked up to my truck for field use TV's computer, fan when camping. the are all right in a pinch but somewhat weak but will keep the fridge going. one thing to remember is anything with a motor will have a draw in amps to get it started and should be factored in when looking for size
We have a 5,000 watt portable and it is of limited use. When the hurricanes came through Central Florida in 2004 (we had 3 hit us in 2 months) the problem was getting gasoline for the generator. The gas stations depend on electricity to pump the gas and they were all down. We used about 7 gal. every 14 hours if I recall correctly. This was a constant problem. Twice we were without power for 7 days. It was July in Florida, need I say more? In the high 90's so we ran a little window A/C unit for our bedroom only which allowed us to sleep. But getting the gas was the problem. I ended up every day driving all over the city. After 3 days it got better, but hauling 5 gal. cans of gas was no picnic either. I seriously thought of a permanent generator running from LNG or propane but the size I needed with a "real" electrician installing it was and is prohibitive. About $6,500 would do it. You don't need the full capacity of the house's electrical system (240v and 200a). You can get by with a lot less and just keep your food and other absolutely necessary things running. I figured about 15KW would do OK for the two of us. You will probably need more. Definitely get an electrician to install it! If a lineman is injured due to your faulty/illegal installation, you can look at some jail time in addition to major $$$$.
'Clinging to my guns and religion
Eagle speaks well
after back to back failours in CT this fall i talked with neighbors who had whole house NG to little in the driveway electric cord 'appliances'
filtered down to $12K for NG runs the house for +$40 a day to a gen using 3 gal of gas running back & forthe changing plugs for fridge, heat, tv& lights...running it 50% of the time= $15/day gas & $500 for the generator.
if i were to do it, a 5K/6k peak Honda generator for $700 used/ 1200 new and a 15 gal gas tank ($45 to buy & $60 to fill) and keep all 3 cars above the 1/2 tak all the time adds 30 gallons
at 5 gal per day...Jethro, ua all wanna help me here with my gazinta's please...
You plug 'em, I plant 'em
...kid can't read at 17 (Garcia/Hunter 1985)
Lack of preparation on your part does not necessarily constitute an emergency on mine
When I had a RV the "Rule of Thumb" was the "exercise" the generator monthly to keep everything lubed and the coils dry.
ΜΟΛΩΝ ΛΑΒΕ: Buy These Stickers Here
"He went on two legs, wore clothes and was a human being, but nevertheless he was in reality a wolf of the Steppes. He had learned a good deal . . . and was a fairly clever fellow. What he had not learned, however, was this: to find contentment in himself and his own life. The cause of this apparently was that at the bottom of his heart he knew all the time (or thought he knew) that he was in reality not a man, but a wolf of the Steppes."
The run time for these generators seems to be fairly short. If electric is down more than a week most would be useless. In the event of a strong electro magnetic event from a sun flare there could be areas that are down for two or three months or more.
I was at Port Saint Lucie Florida hit by a hurricane and electric was out for more than two weeks. Generators were all useless due to lack of fuel. People,just the the idiots they are, didn't use the fuel wisely and partied and ran the AC full time thinking the outage would never last two weeks. It did. Just imagine what two months would be like.
"Confidence is food for the wise man but liquor for the fool"