Home Generators

[BungeeII]

Dangers of using a home generator for backup power to a house:

#1 Carbon Monoxide
This is called the "silent killer" for a reason, right? No warning signs here. Please keep your portable generator outside.
#2 Fire hazard via undersized cable
Please make sure your extension cable is sized properly. Too small of a cable can be a major fire hazard.
#3 Danger of electrocution to oneself
Think "suicide cable". A homemade cable with male connectors on both ends is an accident waiting to happen.
#4 Risk of damaging equipment
If you connect your generator to your house without disconnecting the main, you are backfeeding what? A street? A neighborhood? A village? Best case scenario is that your breaker trips. Commonly, you're going to suffer damage to the generator.
#5 Danger of electrocution to a utility worker
This is really tied into risk #4, the problem of "backfeeding". The greater likelihood is #4, BUT you still have to be cognizant of the fact that the moment you connect that generator to the panel with the main on, that "oops" moment, there very well could be an unprotected lineman working.
Yes, it's more likely they're going to observe safe work habits.
Yes, it's more likely your breaker will trip.
Yes, it's more likely you'll damage your equipment by backfeeding to a major load.
But, there's also a possibility that the service is being done right in your front yard. Or that at the point you're plugging in, they're servicing the "dead" line.

So, there are definite dangers in "make-shift" generator installations.

 

[Dargo]

Dangers of using a home generator for backup power to a house:

#1 Carbon Monoxide
This is called the "silent killer" for a reason, right? No warning signs here. Please keep your portable generator outside.
#2 Fire hazard via undersized cable
Please make sure your extension cable is sized properly. Too small of a cable can be a major fire hazard.
#3 Danger of electrocution to oneself
Think "suicide cable". A homemade cable with male connectors on both ends is an accident waiting to happen.
#4 Risk of damaging equipment
If you connect your generator to your house without disconnecting the main, you are backfeeding what? A street? A neighborhood? A village? Best case scenario is that your breaker trips. Commonly, you're going to suffer damage to the generator.
#5 Danger of electrocution to a utility worker
This is really tied into risk #4, the problem of "backfeeding". The greater likelihood is #4, BUT you still have to be cognizant of the fact that the moment you connect that generator to the panel with the main on, that "oops" moment, there very well could be an unprotected lineman working.
Yes, it's more likely they're going to observe safe work habits.
Yes, it's more likely your breaker will trip.
Yes, it's more likely you'll damage your equipment by backfeeding to a major load.
But, there's also a possibility that the service is being done right in your front yard. Or that at the point you're plugging in, they're servicing the "dead" line.

So, there are definite dangers in "make-shift" generator installations.

I'd have to say that is pretty sound advice. My home and guest house were wired with separate disconnects from the line in. At the time, this was code in my area (no longer is code according to local electricians, but I don't know why). Two different electricians told me that those outside disconnect boxes are a perfect place for them to install automated transfer switches when I get one larger generator to run my whole house.

Right now I just have 2 relatively small gasoline powered generators, one Honda and one Yamaha. The Honda is 8500 and the Yamaha is 6500. Last year when an ice storm had our power out for well over a week I'll readily admit that it was a royal PIA to have 12 gauge extension cords run everywhere and to have to shut each generator down on roughly 10 hour intervals to refuel them and check the oil levels. That doesn't even mention the hassle of keeping a half a dozen jerrycans filled with gas.

Since my home is somewhat isolated everyone around me had power days before I did. When the utility workers finally got to me I had the opportunity to talk with the crew quite a bit. They had to replace the transformer that sits in my yard because a transformer upstream from it failed and, in doing so, killed the one that feeds my place. Anyway, they told me that they were glad to see extension cords running from my generators and not one heavy cable backfeeding my home. They told me that, although it's possible, it's very unlikely for a lineman to get zapped from a backfeed. Apparently that is the first thing on their mind when they were going about their business because so many people in our area were doing so. They also told me about some 'floating' ground with most portable generators that most people don't account for. They told me that if I backfed my home without setting it up correctly to prevent a floating ground (I honestly don't know exactly what that is - have an idea from their description, but am not really sure), the homeowner will fry most every electrical item in their home that has a transformer in it. Maybe someone else here with more electrical knowledge can expand on this issue.

I'm now in an indecisive mode because I can't decide between a natural gas powered home generator or a diesel powered one. Since I live in an area that has a real possibility of earthquakes, I fear that I wouldn't have NG if that disaster struck. The utility workers told me that they would shut off NG immediately if we had a major earthquake to prevent fires and explosions. I have a small diesel tank, 550 gallons I think, for my equipment and could run a diesel generator for a while on that if I had to. However, I'd be concerned about leaving the diesel tank with the generator full for long periods of time and end up with bad fuel in the tank when I really need the generator. So, here I sit with no home generator and only the two small gas powered units due to indecision...

 

[QueBota]

I installed a 50 amp transfer panel which included the interlock switch to make sure you were running either utility power or generator power. That works fine but it is a pain to figure out what you are going to run via the panel and what you are going to run via utility power.

I don't understand the perceived saftey factor of the transfer setup WRT the safety of the utility co. personel. I do see how it can keep you from powering your home with utility and generator power at the same time. However the transfer switch setups I have seen do nothing more than throwing your main breaker when it comes to isolating your home power from the grid. The transfer switch breaks the connection of the hot wires leading to the grid but does not break the neutral, the same thing that the main breaker in the panel does. I think I understand this but if someone could add some additional info regarding the separation issue I would appreciate it.

I installed a 50 amp breaker in my main panel connected to a female outlet via a 8 gauge outdoor rated cable, as shown in the previous image. When the power goes out I fire up the generator, shut off the main breaker, plug the generator cord into the female outlet (weather protected, twist lock) on the side of the house then plug the other end into the generator. I then begin flipping the breakers for the circuits that are necessary in the house. I have several laminated copies of this procedure. One connected to the generator, one at the main service panel and several loose copies that I can carry with me. I always read through the sheet even though I may have performed the procedure over 20 times.

I have a 14K surge, 12K generator powered by a 24 hp B&S Vanguard. It is a Coleman Powemate circa 2003, not the best but it has approx 200 hours on it and has performed OK. It is a thirsty unit, it uses approx 1 gallon per hour. It doesn't' like the newer 10% ethanol gas, my next unit will be diesel powered, looking around for a good value on one that will provide 50 amps at 220v.

The only way I know of to completely separate your home from the grid is to pull the meter, which we used to due when I lived in a rural area of PA. This was very common and the power co never hassled anyone regarding the missing tag. The other way is a relatively expensive knife or similar switch which actually physically separates your home from the grid. In my case I would need a switch rated to match my service panel which is 200 amps and my util co and county would want to be involved in the install.

I feel my current setup is safe and adequate for my needs. I would like to have a disconnect between the meter and the house and hope to add one in the future. I found the transfer switch setup limiting in the circuits which could be used. I have instructed my wife and oldest son on power management. Fortunately whoever wired my main panel when the house was built "balanced" the 220 loads between the legs of the panel. That is approx half of the 220 breakers are on separate sides of the panel.

I can tell when the power comes back on by looking for lights around my place, a phone call from a neighbor or my checking my meter on the outside of the house.

I have spoken to utility company line crews and supervisors when they were working our area during outages regarding generator power. They indicated their safety should not be a problem as they treat all lines as live no matter what the circumstance. They instructed me to make sure I flip the main breaker off before powering the house and to make sure the generator was properly vented to prevent carbon monoxide from entering the house. They also told me to make sure the generator was properly grounded as many folks neglect the grounding provision built into generator.

My setup works for me, I feel it is safe for the utility co employees as well as my family. I wouldn't suggest anyone else use this method nor would I install such a setup in anyone elses home. However, this setup is very common in my area and have never heard of any problems running backup power in this manner.

Would love to have a whole house, auto transfer propane or diesel setup but it is not in the financial cards at this time.

Dave

 

[Dargo]

I have a 14K surge, 12K generator powered by a 24 hp B&S Vanguard. It is a Coleman Powemate circa 2003, not the best but it has approx 200 hours on it and has performed OK. It is a thirsty unit, I uses approx 1 gallon per hour. It doesn't' like the newer 10% ethanol gas, my next unit will be diesel powered, looking around for a good value on one that will provide 50 amps at 220v.

I think you provided great info and also brought up a question I have in my mind. I'll use the 8500k Honda generator for example since it has more time on it. I changed the oil after it's first 5 hours as the manual stated is required. I then changed it at 25 hours. Again as per the manual. After that, it supposedly is considered 'broken in' and 50 hour oil change intervals are suggested. That is what I've done and I've used Royal Purple synthetic oil after that first 30 hour break-in time. My question is this; how long can I expect an air cooled Honda engine to run before problems? I think it has 500 and something hours on it now. Performing maintenance as prescribed, making sure I run it about 1/2 an hour every month to month and a half and making sure I keep fresh gas in it, how many hours should I expect out of it? I can't recall exactly how old it is, two, maybe 3 years. It is a single cylinder engine rated at 13 hp. I went out and looked at it and I was mistaken about it being 16 hp and the 8500k is only the surge rating with a continous rating of 6500k. I can't find a link to my exact model, but this one looks pretty well identical but they've raised the ratings to 8750k surge and 7000 continous. Honda Powered 8,750 Watt Generator

I can't see any changes to raise the output. The Honda engine is the same. I guess the generator head may be more efficient. Anyway, how many hours can a guy expect something like that to run with proper maintenance? I have no desire to run it for a couple hours, shut it off for a few hours, then repeat the cycle. When I need my generators, I will run them non-stop except for stopping for fueling, checking the oil level and changing the oil. At, say, 550 hours am I getting into the 'well worn' stage? Here's the Yamaha powered one I have, but it only has about 300 hours on it RIDGID 6800W Generator W/Yamaha MZ360 - RD6800 at The Home Depot. Again, how many hours will those engines run?

 

[natem]

Work for local highway dept, They had use sit through a class about power lines tangled up in trees and stuff. Any ways the power company put it on for use. Was interesting, the home generator situation came up in discussion. This guy was saying that even if you turn the main off the generator can still back feed through the ground, or the negative, not sure if this is true or not. Also they stated that in outages where people are useing the generators they go around in neighborhoods and when they hear them this guy goes and checks to see how they are hooked up. if they are not correct the power line is disconnected at the street, not sure how you go about getting it hooked back up. To sum things up looks like a few hundred bucks will get you the transfer switch, and a licenced electrician to hook things up properly. Seems cheap to me, and also could save somebody's life and your house too. How do you put a price on that?

 

[BobRip]

Performing maintenance as prescribed, making sure I run it about 1/2 an hour every month to month and a half and making sure I keep fresh gas in it, how many hours should I expect out of it?

I have two generators and one says run it every three weeks and one every two weeks in the owner's manual. I run them both at the first and 15th of the month with electric heats plugged into each one. One has a Honda engine. I would say you are not running yours quite enough. Having an engine sit for six weeks seems like a long time. Also the generator head itself will soak up moisture and running, particularly with a load, will help dry it out. I don't know this for sure, but a friend did not run her's for two years and had the generator head short out after a couple hours of running after a hurricane. Electric heaters are cheap and can be handy during a power outage. Also using the electric heaters let's you know that they are actually putting out power, not just spinning the generator.

 

[MossRoad]

I'd have to say that is pretty sound advice. My home and guest house were wired with separate disconnects from the line in. At the time, this was code in my area (no longer is code according to local electricians, but I don't know why). Two different electricians told me that those outside disconnect boxes are a perfect place for them to install automated transfer switches when I get one larger generator to run my whole house.

Right now I just have 2 relatively small gasoline powered generators, one Honda and one Yamaha. The Honda is 8500 and the Yamaha is 6500. Last year when an ice storm had our power out for well over a week I'll readily admit that it was a royal PIA to have 12 gauge extension cords run everywhere and to have to shut each generator down on roughly 10 hour intervals to refuel them and check the oil levels. That doesn't even mention the hassle of keeping a half a dozen jerrycans filled with gas.

Since my home is somewhat isolated everyone around me had power days before I did. When the utility workers finally got to me I had the opportunity to talk with the crew quite a bit. They had to replace the transformer that sits in my yard because a transformer upstream from it failed and, in doing so, killed the one that feeds my place. Anyway, they told me that they were glad to see extension cords running from my generators and not one heavy cable backfeeding my home. They told me that, although it's possible, it's very unlikely for a lineman to get zapped from a backfeed. Apparently that is the first thing on their mind when they were going about their business because so many people in our area were doing so. They also told me about some 'floating' ground with most portable generators that most people don't account for. They told me that if I backfed my home without setting it up correctly to prevent a floating ground (I honestly don't know exactly what that is - have an idea from their description, but am not really sure), the homeowner will fry most every electrical item in their home that has a transformer in it. Maybe someone else here with more electrical knowledge can expand on this issue.

I'm now in an indecisive mode because I can't decide between a natural gas powered home generator or a diesel powered one. Since I live in an area that has a real possibility of earthquakes, I fear that I wouldn't have NG if that disaster struck. The utility workers told me that they would shut off NG immediately if we had a major earthquake to prevent fires and explosions. I have a small diesel tank, 550 gallons I think, for my equipment and could run a diesel generator for a while on that if I had to. However, I'd be concerned about leaving the diesel tank with the generator full for long periods of time and end up with bad fuel in the tank when I really need the generator. So, here I sit with no home generator and only the two small gas powered units due to indecision...

I'd go with the diesel if you are worried about the New Madrid fault. Diesel fuel will keep a LONG time and you can always use it in a tractor or truck to cycle it out of the tank. A sister company of ours has 10,000 gallons of diesel in a generator tank with no plans to cycle it out. It is dependable.

 

[Dargo]

I have two generators and one says run it every three weeks and one every two weeks in the owner's manual. I run them both at the first and 15th of the month with electric heats plugged into each one. One has a Honda engine. I would say you are not running yours quite enough. Having an engine sit for six weeks seems like a long time. Also the generator head itself will soak up moisture and running, particularly with a load, will help dry it out. I don't know this for sure, but a friend did not run her's for two years and had the generator head short out after a couple hours of running after a hurricane. Electric heaters are cheap and can be handy during a power outage. Also using the electric heaters let's you know that they are actually putting out power, not just spinning the generator.

I don't recall exactly how often my manuals say to run the engines. I'll just say that I believe you. I'd like to say that I run (exercise) mine more often, but I just don't. I'll spare you the excuses. I'm sure you could guess all the standard excuses. I'm just being honest. I really ought to try to run them a bit more often. Thanks for the reminder. Still, how many hours do you think they'll last?

 

[Dargo]

I'd go with the diesel if you are worried about the New Madrid fault. Diesel fuel will keep a LONG time and you can always use it in a tractor or truck to cycle it out of the tank. A sister company of ours has 10,000 gallons of diesel in a generator tank with no plans to cycle it out. It is dependable.

That's precisely the fault that concerns me. According to the scientists, we are about 100 years overdue for "the big one". Apparently I am leaning towards a diesel unit. Otherwise, I would have already have purchased a NG unit through a BIL of mine who runs a HVAC company and offered to sell me one at cost. Maybe I'm being paranoid, but I really do have a major concern about not being to use such a generator (NG) when I'd really need it for an extended period of time. As I've mentioned in another thread, for what I want, my electrician 'sized' me to need between a 40k minimum and likely a 50k unit. Those sizes seem to be relatively common in diesel.

 

[MossRoad]

We've had a little Coleman 4500 8HP B&S engine since 1992 or 1993. I only run it about twice a year. I keep stabil in the gas to keep it from spoiling. Other than the occasional power outage that lasts 1-2 hours we only used it during one disaster where it ran for 3 days off and on. The thing works well for the price. About $400.00.

I am guilty of back feeding. I shut off the main disconnect under the meter and then the main breaker in the panel. I turn off all the breakers in the main panel, then head out to the unattached garage, which has a 50AMP 220V sub panel. I have a 30 AMP outlet in the garage that I back feed with a male-male cord. Once everything is plugged in and the generator grounded, I start it, let it warm up a few minutes, then return to the house and turn on the needed breakers. I watch the neighbor's lights to see if the power returns.

The reason I went this way is because the cost of an interlock or transfer switch and an outside outlet on the side of the house is just too expensive for a once a year situation. The only dangers I see is me forgetting to pull TWO breakers, not plugging in the male cord before starting the generator, or forgetting to turn off the generator before turning the two breakers back on again or removing the male cable. None of that is likely as I am the only one that performs the procedure and I have it rehearsed and practiced.

For everyone else I would recommend a professionally installed transfer switch. If we ever build a new home, I will get a proper installation.