Upcoming project - A standby home generator

[Harvey]

Here on the Gulf Coast (Hurricane Country) we have occasional power outtages. The short ones can be inconvenient but the ones that last for days can result quite a monetary loss in spoiled food, etc. I've had a small portable generator for years and while it has been (marginally) useful, I'm now considering something a little larger, automatic, and permanently mounted.

I'm not new to electricity and electronics but residential generator systems is new territory for me. Any of you have one or experience with them? Recommendations? Horror stories?

Thanks,


Harvey

 

[Ray C]

Harvey,

I have the same issue here near the eastern shore. I used to rebuild diesel gen-sets as a hobby... That said, if you go with a commercial unit such as a "Guardian", you'll probably need access to a natural gas line. They are multi-fuel, typically powered with a twin cylinder Briggs-Stratton Vanguard engine (or something similar) but the most common configuration is natural gas followed by propane. They are good for about 15kW peak and do OK at 10kW continuous but, those engines do not have an extended service rating and are good for about 500-800 hours before needing a partial rebuild. That's roughly 1 month of continuous use before it needs service. Expect needing to replace the starter battery every couple years so, find-out how much they cost. Most places that install those will try to sell a service contract with an annual fee. -It may be worth it. Many folks around here have them and the only ones that work reliably are for the folks who get them serviced regularly.

Most important is how it's wired into your service panel. Most places will install a sub-panel that will service a subset of the circuits in your home -usually just 6 circuits. There are other ways to wire it but, they'll charge more. Do realize, 10kW is not enough to handle central air or electric furnaces -not by a longshot.

I thought about getting one myself but, I use 5kW portable for the brief outages and I have a 4cyl heavy duty diesel powering a 15kW genhead that has a service rating through the roof. It will put out 15kW all day long for months on end and probably has a 1 year continuous use rebuild cycle.

Ray

Here on the Gulf Coast (Hurricane Country) we have occasional power outtages. The short ones can be inconvenient but the ones that last for days can result quite a monetary loss in spoiled food, etc. I've had a small portable generator for years and while it has been (marginally) useful, I'm now considering something a little larger, automatic, and permanently mounted.

I'm not new to electricity and electronics but residential generator systems is new territory for me. Any of you have one or experience with them? Recommendations? Horror stories?

Thanks,


Harvey

 

[Harvey]

Ray,

I just assumed that standby generators were gasoline powered. I live out in the country and don't have natural gas service available. (And I don't want to install a propane tank just for a generator.) Since you used to work on diesel gen-sets as a hobby, please give me an idea of what my options are. I'm a DIY-kinda guy and will likely install it myself since I refuse to pay good money for someone to do shoddy work!

When the power is out following a hurricane, it is too hot and humid to sleep without an air conditioner. Therefore, I'm looking for enough KV to power a refrigerator and freezer, a microwave, a few lights, a TV, and a small window AC in the bedroom.

Thanks,

Harvey

 

[Terrywerm]

I could offer some insight based on a standby generator that I used to service and take care of. The best part was lighting it off once a month for 30 minutes. But I believe a 16V149 Detroit Diesel generator putting out 1200 KW would be overkill for a household application. :rofl:

As nice as a permanent installation would be, I cannot justify the cost for one. Power outages here are neither frequent enough, nor do they typically last more than a couple of hours. Being in the Midwest, power outages here are generally more localized and usually only last a few hours. Winter outages due to ice storms and downed lines can cover a greater area and have more impact. I was able to justify purchasing a Honda EU2000i portable generator though, and love it. We can take it camping when we go to places that do not have electricity, it is quiet enough for that purpose (56 dB). When camping it really only gets used to recharge the camper's batteries once every couple of days or so.

At home, for extended emergency use, there are two ways to look at it, basically winter and summer. In winter, frozen items get taken out of the freezer, placed in boxes and put in the garage. Refrigerated items get placed in coolers, stored in the garage at night, stored in the house during the day. The generator gets used to run the furnace and a couple of lights. In summer, the generator is used for the refrigerator, freezer, and a couple of lights. The chest freezer gets plugged in just a couple of times a day which is plenty if we can manage to keep the door closed most of the time. The tough ones are the ones that occur during spring or fall when temperatures tend to go below freezing at night but above freezing during the day. Then we need refrigeration and household heat all at the same time.

Since we are accustomed to 'dry camping' with minimal electrical power and bottled water, extended power outages for us are simply another exercise in camping with minimal resources. The kitchen range uses natural gas, so cooking is not a problem. We are on city water, which is not a problem, and that system is backed up by emergency generators. My hot water heater is also on natural gas, so all I need to look out for is home heating and refrigeration of food items.

In the twenty some odd years that we've been in this house, there has only been one time where we had need of a generator. It was in summer, so we only had to look out for our frozen/refrigerated items. My great uncle had a farm not too far away where I helped out all the time (he still had power), and we borrowed a tractor and his PTO generator which provided enough power to easily keep our necessities going. A couple of neighbors chipped in for fuel and stretched out extension cords to their refrigeration equipment too. We kept it running during the daylight hours, but shut it down at night. Nobody wanted to listen to that tractor roaring all night! Luckily that power outage only lasted three days. The most tedious part was babysitting the tractor... to keep the curious neighborhood kids away so they didn't get caught in the PTO shaft!

The only thing that I might be able to add that may be of some use is that there are different kinds of transfer switches, which isolate your system from the power grid when your generator is running. As I understand it, many of the cheaper ones do not provide adequate protection, so make sure that you get the right one for your installation.

Sorry about getting so long winded, I thought some of our experiences might prove helpful to other readers if they start planning for their own emergency procedures.

 

[Harvey]

Sorry about getting so long winded, I thought some of our experiences might prove helpful to other readers if they start planning for their own emergency procedures.

Actually, Wermy, it was not only educational, it was entertaining as well.

Thanks,

Harvey

- - - Updated - - -

I've got an extra 1930 4 cylinder Ford flathead engine that puts out 40hp (on a good day). Could it be used to run a generator? That would make a neat project!


Harvey

 

[twstoerzinger]

One of the big concerns will be the transfer switch. The power companies are usually very insistent on having a certain style / design / rating of transfer switch. They don't want you to electrocute one of their linemen working on what was believed to be a de-energized line.
You might check on your power company's website for information on transfer switch requirements for home generators. Where I live, the power company has a pretty good treatise on home generators, transfer switches, and the installation / approval procedure.
Terry S.

 

[xalky]

The 40 hp motor would run a generator, but now you're going from something that is designed to run automatically to hillbilly engineering.:LOL: I have a 7500 watt portable generator that I use to power my house when the power goes out.

When the power goes out, I shut down the main 200amp panel breaker and I run a heavy cord from my generator, outside, to a stove plug in my basement and backfeed into my house through that outlet. I can pretty much run the whole house. We heat, cook and heat hot water with gas so there's no heavy draws. I tell my wife not to use the dryer. I have a freezer and 2 refrigerators no problem. We can even run selective window air conditioners. I had to do it for 3 days once.

Marcel

 

[Ray C]

Building your own genset is a little more involved than you might think... I'll provide some background but in the end, I'll flat-out recommend getting (for your case) an 8000W gasoline portable because building a proper unit takes some time and money.

Some basics (learned from the school of hard knocks):

Most gasoline units and even the natural gas ones with twin cylinder engines tend to rattle themselves to death after a while. None of them have service lives much beyond 1000 hours before they need new valves and rings. Often times, the valve heads need to be replaced because the valve seats are not resurfacable. The work is not hard to do yourself though. My biggest complaint is the noise from a 3600 RPM engine. Even with mufflers installed, they're noisy. Despite all this, it's still not a bad deal financially.

When making a high-service-life unit, you need a diesel engine that puts out the required horsepower at 1800 RPMs. Most genheads need to be driven at either 1800 or 3600 RPM. You're not going to find any diesel engines that spin at 3600. The next trick is to get a governor to keep the speed exactly at 1800 (+/- 2%). Some engines have built-in governors. External governors are quite costly. I'm a big fan of Kubota diesel engines. They are perfect for this application and are the #1 engine used in truck refrigeration units. There are millions of them out there and they run the daylights out of them. You can buy them used for about a grand and spend another $600 to rebuild them (if you do it yourself). You'll need a 40HP motor to produce 20kW (when running at 1800 RPM). You need to look-up the HP rating curve of the engine to verify proper sizing. As a rule of thumb (which is very accurate) multiply horsepower x 700 to determine how many Watts are available. This figure takes into account losses and overhead capacity to increase service rating.

Next trick is the gen head and this is what I always use: http://www.ebay.com/itm/24KW-ST-Gen...02657318?pt=BI_Generators&hash=item35cecab326

After this, get the welder out and make a frame to mount the engine. Buy direct couplers to drive the generator (don't go with sheaves and belts). Make a stout steel frame and set it on wood planks.

There are some commercially available engine control units... I always made my own.

OK, all this sounds easy but, it's more involved and expensive than you might think -and that's why I generally recommend a portable gasoline unit. Try to get one with twin cylinder engine as they run smoother and you'll see less flicker. If you maintain it well, run it under load every 4 months, drain the fuel when not in use -you'll get good enough service out of it.

EDIT: BTW, you need a good radiator and the engine must have a fan. A pusher fan is not necessary but nice. A typical automotive pull fan works well. Just make sure the radiator has shroud if you use a puller fan.



Ray

 

[GK1918]

Not an issue. first you got ta pull the "line" breaker service" put gen set outside plug in to any wall socket, energize the house only
remembering the gen set out put. so if you got a small one that means refeferator couple lights. our last hurricane I put my tool truck
Miller welder. with a cable thru the window. good ta go. the chord two males MAKE sure you disconnect the main or your gen set will
try to power the hole neighborhood ---then poofffffff ......

 

[wpala]

Hi

Your hook up is a dangerous I always thought about doing the same I have a plug available in the garage 240V 60amp I have a 8KV diesel generator (those are the best since they are used for continuous duty plus they rotate at 1800 rpm usually have a large fly wheel so even a spike in the line will not choke the generator) the reason is dangerous is that common (white) cable can carry the power back to the pole and can kill the lineman (common cable is not interrupted at the box junction by a breaker only hot wires), now this will only happen if your equipment is not wired properly and there is a short somewhere yet there are steep fines for this type of hook up the best one is the generator plug in the base of your meter those are fairly new and you do not have to have a sub panel but quite expensive about 1200$
As for generators as I said the diesels are the best you want something around 8-12 KV those will run most of the house everything depends how frugal you are with your energy use and what exactly you need running at the same time easiest way is to calculate the wattage of all the equipment need to be use and go from that the lower 6-8 KV Genstets will be very fuel efficient with the right engine you can expect 0.75 gal/hr at 3/4 load, bigger ones are nice but they burn a lat more and if you don't use the electricity they produce is all waste

this is the new type of generator hook up



Paul

The 40 hp motor would run a generator, but now you're going from something that is designed to run automatically to hillbilly engineering.:LOL: I have a 7500 watt portable generator that I use to power my house when the power goes out.

When the power goes out, I shut down the main 200amp panel breaker and I run a heavy cord from my generator, outside, to a stove plug in my basement and backfeed into my house through that outlet. I can pretty much run the whole house. We heat, cook and heat hot water with gas so there's no heavy draws. I tell my wife not to use the dryer. I have a freezer and 2 refrigerators no problem. We can even run selective window air conditioners. I had to do it for 3 days once.

Marcel