Whole house generator and panel question

[hornadylnl]

For less than $4000, I have a 400 amp transfer switch and a 10k military diesel generator. These generators are capable of 15k watts. Rated to burn 2 gallon an hour at full load.

I don't see the need to run 24/7 in an outage. The cost of fuel will run you out of house and home. My plan is that if we have another long term outage like the early 90's ice storm isto run a couple hours at a time a purple times a day.

 

[Leadeye]

I had mine setup when we built the new house, runs off of propane and has an auto on/off disconnect. It's wired to provide enough power to keep us comfortable in an emergency, most of the circuits are in the basement so we move down there, take the microwave if it's going to be a long time. Extra circuits upstairs run the fridge and freezer and some outlets in the garage. Runs the fan on the woodburner and a plug for a window AC that I keep in storage. I thought about it and decided that I didn't want to run everything, just enough to stay comfortable and keep that going for a good while. Odds are power is going to come back on soon, in an "American Blackout" situation I could stretch the propane tank out for a long time.

 

[hoosierdoc]

We have 400a service and two 200a panels, I assume that is what I have since I have one meter. The 20kW generator he quoted was a kohler and took 290k btu. I called vectren and they said we had plenty of gas supplied to the house for our current needs plus the generator.

I do need to keep in mind emergency power is not meant to be full comfort power. What does 1 million btu of NG cost? $22 or so? Then running full bore would be $7/hr or so? Not all that bad for convenience.

generac gave me his number and he pitched the kohler. Heh.

 

[Brian Ski]

We have 400a service and two 200a panels, I assume that is what I have since I have one meter. The 20kW generator he quoted was a kohler and took 290k btu. I called vectren and they said we had plenty of gas supplied to the house for our current needs plus the generator.

I do need to keep in mind emergency power is not meant to be full comfort power. What does 1 million btu of NG cost? $22 or so? Then running full bore would be $7/hr or so? Not all that bad for convenience.

Good to know you are looking into it the bigger one would be almost double so it was close to my numbers. I think a regular gas meter is good for 500,000 btus. IIRC somewhere around there. So the bigger one with all your other NG items would be around the top. (did some research and there are several sizes of meters)

$7 an hour for 24 hours is $168 a day. But I think that may be high. Unless your area has a higher rate than mine. My generator is portable and I converted it to a tri fuel. I ran it for 12 hours of more and it didn't even make a blip on the gas bill. I was nervous at first. Hate to see the bill jump $100. Gasoline would have ran me 10 gallons give or take. That would have been $40 back then.

 

[Scout]

Me personally, if Generac is using actual power contactors (relays made for high current) then I would replace those with SSR's(Solid State Relays) which have NO moving parts and failure rate is much lower than a power contactor.

How often do you expect the power to go out? There are milllions of factories that run regular contactors, on and off dozens if not hundreds of times a day, and the failure rate is not that high. Eventually they do wear out. Normally the contacts wear and fail to close the circuit. For a home, where they might switch once or twice a year, I wouldn't have an issue with them,.

 

[CountryBoy19]

It is true the circuit breaker trips when the load demand exceeds the generators capable output. This breaker is an OUTPUT breaker. The generator does not shutdown when this breaker is tripped (load exceeds genset output). It is true that very old generators will slightly raise speed during an abrupt shed of ALL loads but most generators have an electronic governor (instead of the former mechanical kind) and the sudden decrease in loads is barely noticed by the generator as far as engine speed regulation. I would hardly call it an "overspeed". All generators have an overspeed switch built in to prevent an overspeed condition. I maintain a (50kw) and (100kw) Kohler genset and they get a sudden decrease of loads in the 20-40a range any given time when the engine(s) are running. (208vac 3 Phase) They instantaneously decrease engine speed within microseconds. You just dont see the sloppy regulation of the old mechanical systems with the newer electronic regulated gensets.


I would seek 2 or more contractors for estimates on a package to fit the OP's needs. Heck, call generac themselves and i am sure they can turn you on to a proven contractor (by generacs standards) or any other brand like kohler, etc.

That's my point, even with mechanical governors you may get a slight "over-speed". And I did mis-speak when I said that. By "overspeed" I meant it would accel beyond normal operating speed (often 1800 rpm for a diesel genset of this size) but the engine is designed to handle quite a bit more than that... you won't damage anything...

WRT mechanical vs. electronic governors, it may be true that most all new gensets in the large size you mentioned have electronic governors but it couldn't be any further from the truth on the 10-30 kw range; those are still mostly mechanical governed (unless this industry wide change has happened within the last year or so)... My dad has several large gensets including a 10 kw, 20 kw, & 45 kw...

 

[Timjoebillybob]

The problem is you are installing an automatic system and wanting to control it manually.

I am not an electrician, but would it be possible to set up both? The automatic transfer for when the power goes out and then a manual transfer so he could decide which circuits to run? Leave it set to the one that needs to be on such as sump (if he has one), furnace, etc and then a separate circuit for upstairs ac etc.

 

[GodFearinGunTotin]

I am not an electrician, but would it be possible to set up both? The automatic transfer for when the power goes out and then a manual transfer so he could decide which circuits to run? Leave it set to the one that needs to be on such as sump (if he has one), furnace, etc and then a separate circuit for upstairs ac etc.

Yes, you could. It's just the matter of another manually operated switch and a little panel work. I'm not in that business but I doubt the pros would offer to do that for you because they want to know what that genny is going to be pulling. But if you knew what you were doing.......

 

[Brian Ski]

Yes, you could. It's just the matter of another manually operated switch and a little panel work. I'm not in that business but I doubt the pros would offer to do that for you because they want to know what that genny is going to be pulling. But if you knew what you were doing.......

The other thing is you need to know if the loading of each side of the generator. They work better with a balanced load. If the electrician sets the generator up properly it should be fairly balanced. If you put too many heavy loads on one side, you can overload the generator even if you are well under the rated load. I have a manual transfer switch with meters on it so it tells me how much of a load is on each side.

I think the more options you give someone to adjust things the more likely of having problems.

Like someone told me the other day.

I bought a whole house generator, we haven't been without power for long for over 5 years.
I bought a nice 2 stage snow blower, now we probably won't get any snow.
If I bought an expensive life insurance policy, I will probably become immortal!!!