without electricity for 48 hours now

[ratto]

Biggest problem is 12 ga. extention cords running to neighbors houses are quite$

12 ga. for the Jesus cord? That's impressive.

And that will go into service automatically even if you're not home, a big plus.

An automatic transfer switch is very convenient. But I wouldn't pick it for myself. In disaster (like fire/flood), I definitely don't want it to kick in automatically to make an already difficult situation even more treacherous.

Storing generator dry helps, but a generator does need periodic exercise (under load, 30%-50%). It's a good idea to keep some oil seals/gaskets periodically lubricated once the generator is used. Also if a generator is kept unused for too long, the residual magnetic field (RMF) in the gen head could potentially diminish too low. Most portable generators in now days are based on brush-less, self-excite design. When the RMF becomes too weak, the gen head will not be able to generate power anymore. It's not fun to manually "excite" the gen head in emergency, especially in total darkness.

The small engines in most consumer grade generators are screaming at 3600 RPM to give the required 60Hz AC current with a 2-poles gen head. This high RPM not only is bad for engine lifetime, but produces a lot of noise and consumes a lot of fuel as well. So if a cheap backup generator is desired, a better solution probably would be to put it to work in conjunction with an inverter + battery bank setup. The generator will only be started to charge the battery bank and to run sustained heavy load. Still having air conditioning during extended power outage in hot summer is a nice luxury to have, but no a must necessity in most cases. Having drinking water supply, preventing food and crucial medicine supply from being spoiled, and keeping limited fuel stock to last as long as possible are far more important.

 

[NW-Bound]

Transferring power at a low voltage like 12V requires a lot of current. And at currents as high as 150-200A, it does not take much resistance to lose a couple of volts like ERD50 described. At the household AC voltage of 120V, a loss of a couple of volts may not be a big deal, but when one starts out with only 12V, that 2V loss is a lot.

RV boondockers know about this. For wiring up the inverter to the battery bank, they place the two only a few feet apart. The wiring size de rigueur is AWG #0. I used AWG#2 when I installed a 2KW pure sine wave (PSW) inverter in my RV. I thought the heavier wire was too difficult to route. I somewhat regretted that.

It is not just the resistance of the wire. Although every connection and contact point was tightened with lug nuts, I lose more than 1V between the battery posts and the inverter input posts when I run the microwave. It was very revealing when I set my DVM to the highest voltage sensitivity, and probed the voltage drop across each connection and each segment of wire. At a current of 150A, one milliohm of resistance causes a 0.15V drop. A milliohm here and there, and soon you are talking about losing 1V.

Regarding refrigeration, out of curiosity, I did a bit of investigation on residential fridge power consumption and wanted to share the info.

An average fridge of 18 cu.ft. would use something like 1.5KWhr/day. It may draw 500W when running, but the compressor cycle is sufficiently short that its average consumption is only around 60W. With that low power, we would think it should not be a big deal to keep it running. Well, not quite.

Storing 1.5KWhr worth of energy requires 125AHr of 12V battery. If we keep the depth of discharge to 50% to prolong battery life, that takes 4 batteries of the 6V golf-cart type. Then, to charge these batteries once a day, we would need a charger with a 60A capacity, run off our generator 2 hr/day. A 1KW generator is sufficient.

RV boondockers do something like the above, except that they use solar panels to charge the battery bank throughout the day. And they often use more than 4 batteries. And they still cannot use the residential fridge and most of them still use the ammonia absorption fridge that burns propane.

By the way, there is a new type of RV/boat fridge that has a high-efficiency 12V compressor. It uses freon just like the usual fridge. They are still pricey; a 6-cu.ft. unit will set you back more than $1500.

So, does the average home owner want to invest in and to maintain equipment like an RV boondocker does?

I would think that keeping the fridge going is the most important thing. I heard that some people could not even go out to eat when their food gets spoiled. All the restaurants nearby also shut down.

Here in the SW, if one wants to stay at home, a small A/C may be a necessity. Not too many are made of stern stuff like the native Americans or cowboys of yesterday who could tough out the 115+ degrees. Quite a few elderly people may expire in that heat, I am afraid.

 

[Andre1969]

Hallelujah, the power just came back on! I think at this point, it's been off about 88 hours or so. I think what caused it, is that my uncle, who lives across the street from me, just bought a generator. :-/

 

[REWahoo]

Hallelujah, the power just came back on! I think at this point, it's been off about 88 hours or so. I think what caused it, is that my uncle, who lives across the street from me, just bought a generator. :-/

Seems to work almost every time - too bad he didn't buy it sooner.

 

[NW-Bound]

Amazing he could still find one on the shelf to buy.

Or should I ask how much he had to pay the scalper?

 

[W2R]

Hallelujah, the power just came back on! I think at this point, it's been off about 88 hours or so. I think what caused it, is that my uncle, who lives across the street from me, just bought a generator. :-/

Wonderful! I hope Khan and others have their power restored soon, as well.

 

[powerplay]

Wonderful! I hope Khan and others have their power restored soon, as well.

+1 I'm hoping for that to.

 

[MichaelB]

Wonderful! I hope Khan and others have their power restored soon, as well.

Same here. My mother and brother have been without power since the weekend as well and are staying with us. Looks like they'll get it back tomorrow.

 

[NW-Bound]

I just saw on the Web that 1.8 million people are still without power. And 300 Canadian utility workers have come down to the DC area to help restore power.

So, it looks like some unlucky people will have to endure a few more days. It was said the heat also hinders the worker's effort to restore power. And the article also says that "U.S. officials fear the death toll could climb because of the heat and widespread use of generators, which emit fumes that can be dangerous in enclosed spaces."

 

[Khan]

Utility folks wandered around ~5PM Monday and said power should be back soon; came on about 3AM Tuesday. Folks working their butts off at 100F many feet off the ground.
Stuff is working now.

Folks on this and other forums offered local help; I didn't need, but thank you all.

 

[W2R]

Utility folks wandered around ~5PM Monday and said power should be back soon; came on about 3AM Tuesday. Folks working their butts off at 100F many feet off the ground.
Stuff is working now.

Wonderful! Glad to hear it.

 

[Purron]

Or a target.

We've always felt kinda vulnerable if we're the only house in the neighborhood with the lights on after a hurricane. I'd rather break out the candles and the BBQ and party like it's 1899.

Yeah baby....party like it's 1699. These folks don't worry about electricity since they don't use it anyway.

"Weird" Al Yankovic - Amish Paradise - YouTube

 

[MichaelB]

Wonderful! Glad to hear it.

+1

 

[samclem]

Stuff is working now.

Woo-hoo! Great!
The electrician who did a lot of work on my house was formerly employed as a lineman by the power company that services Dayton. A few years ago he told me they had cut back on the number or repair personnel (to save $). It appears the power companies have good reciprocal agreements to help each other out when a big outage occurs, but when the outage is widespread I think their resources get stretched. And no matter what, there will be some delays while they travel.

They are working hard, and I'm grateful they are here.

 

[NW-Bound]

Happy July 4th to Khan and others who got their power back.

It's too tough to "party like it's 1699". You can't have the Internet, for one thing...

 

[Khan]

Electricity is a very good thing.

 

[powerplay]

Electricity is a very good thing.

It sure is! I'm happy that you have your power back now. It gets old pretty fast when the power is off.

 

[MDJO]

"When we moved to WV I had the transfer switch installed straight away" - Walt, how much did the transfer switch cost you? I assume that takes you off the grid and allows you to plug in the generator.....

 

[NW-Bound]

I am lucky to live where we never have to worry about tornadoes, hurricanes, or winter storms. The only risk of losing power would be due to overload of the grid or equipment failures when every home's A/C is running flat out in the summer heat.

Still, this thread made me curious about "whole house genset", so I looked on the Web. I found one of those permanently installed ones that can run off natural gas, if one is lucky to have that plumbed into the lot. A photo of a typical installation follows. I am impressed that this 20KW generator is not that big. It does not look anything like the monstrous 20KW diesel gensets that I posted photos of earlier.

Then, I saw on the Web that a genset like that, including an auto-transfer switch, costs less than $5000 (not including installation). That's not bad at all.

Operation of the whole thing is automatic. When power is lost, the genset starts itself up in 10-15 sec, the transfer switch cuts it in, and you have power. When the grid is back on-line, the transfer switch goes back to outside power, and the genset shuts itself off.

Every so often (once per week or month), the genset starts up to exercise itself for something like 10 min. All you do is to change oil and air filters when they need to be. Pretty slick! I would have installed something like this, if I have [-]an excuse[/-] the need.

 

[Texas Proud]

I am lucky to live where we never have to worry about tornadoes, hurricanes, or winter storms. The only risk of losing power would be due to overload of the grid or equipment failures when every home's A/C is running flat out in the summer heat.

Still, this thread made me curious about "whole house genset", so I looked on the Web. I found one of those permanently installed ones that can run off natural gas, if one is lucky to have that plumbed into the lot. A photo of a typical installation follows. I am impressed that this 20KW generator is not that big. It does not look anything like the monstrous 20KW diesel gensets that I posted photos of earlier.

Then, I saw on the Web that a genset like that, including an auto-transfer switch, costs less than $5000 (not including installation). That's not bad at all.

Operation of the whole thing is automatic. When power is lost, the genset starts itself up in 10-15 sec, the transfer switch cuts it in, and you have power. When the grid is back on-line, the transfer switch goes back to outside power, and the genset shuts itself off.

Every so often (once per week or month), the genset starts up to exercise itself for something like 10 min. All you do is to change oil and air filters when they need to be. Pretty slick! I would have installed something like this, if I have [-]an excuse[/-] the need.

From what I have read (and it is not much), this one is WAY to close to the house...

 

[Nords]

A Note: The startup loads on some of these items are 2-3 times the running loads. A refrigerator that uses 600 watts when running can often need 2000 watts to start.

I wish I still had access to the military gear to dial the bus voltage down to 80-90 VAC to experiment with whether that refrigerator compressor will start up or not...

In a test where he put a 1,000W load on the inverter, he found that the Prius would turn itself on for 2.5 min, then off for 9 min. I was surprised that the battery could not sustain the 1KW load for longer than 9 min. Upon further research into the HV battery capacity, I thought that to be reasonable.

I think Toyota's design criteria for the battery was to square off the vehicle's torque curve, but it doesn't have much capacity at high draw. You can chirp the tires pulling out from a stop light, but you can watch the battery drop from 80%+ to <40% before you get very far. And then the internal combustion engine finally spins up and fires up to carry the load.

Yeah baby....party like it's 1699. These folks don't worry about electricity since they don't use it anyway.

Every so often (once per week or month), the genset starts up to exercise itself for something like 10 min. All you do is to change oil and air filters when they need to be. Pretty slick! I would have installed something like this, if I have [-]an excuse[/-] the need.

It all sounds great when you're buying it, but I can't help think "maintenance hog". It also sounds like a lot of money to preserve a refrigerator full of groceries (~$250?) and to cool off a room.

And to stay current on the firearms you're gonna need to defend your property when someone else wants you to "share the power".

I know that my body is no longer adapted to cold weather, but I wonder if living in climate-controlled environments has hurt our survivability more than it's helped our productivity.

 

[ERD50]

I'll also run some numbers on the alternator issues that samclem brought up. I think I'd be OK, since I'm only looking at running a couple things at a time.

I also can give some experience with cheap generators, but later.


When I dig up my numbers and have some time, I should be able to shed some light on this.

-ERD50

OK, fireworks over, getting back to those numbers I promised to samclem, youbet and NW-Bound.

My old fridge and freezer, when running, draw 244 and 155 Watts. Duty cycle was ~ 55%, so 135 and 87 watts average (newer ones are more efficient, maybe 40% less, but that doesn't include ice-maker - turn it off!). I kept these on the kill-a-watt for days, so it would include defrost cycles on the fridge (manual defrost on the freezer).

So if I assume ~ 20% losses, the amp draw at 12V is conveniently 1/10 the watt rating. So the fridge would draw ~ 13.5A at 12V . A typical 100AH car battery would go for 7 hrs before needing a charge. Probably less though - I think the 100AH is at an even lower average current, it does degrade pretty steeply as you increase current. But wide ballpark numbers here.

But 13.5A shouldn't be too stressful on the alternator.

Now, lets say we've been w/o power a while, fridge and freezer getting warm, so we want to get both going, and figure they will run 100% for the first hour to 'catch up'. Combined ON current at 12V is 40A, so we are getting closer to limits of the alternator. Not sure it even can put that current out at idle. But the battery could probably deliver this on its own for ~ 1 hour, then the load should lighten as they cycle. So the load would probably be split between the battery and the alternator. I'd probably want to get the car out on the road at higher speeds for a while after I was doing this.

My 3/4HP furnace fan, wired med/hi for heat, took 800W - so that's pushing it at 80A. But running the furnace for 1/2 hour at a time should get you into a safe temperature for hours if it isn't too cold out. My furnace runs only ~ 50% in pretty cold weather to keep at 68F. It takes hours to lose a few degrees.

OK, I'll save the genset talk for the next post.

-ERD50

 

[ERD50]

Back to the genset...

It all sounds great when you're buying it, but I can't help think "maintenance hog". It also sounds like a lot of money to preserve a refrigerator full of groceries (~$250?) and to cool off a room.

That's the conclusion I came to. There is a 'siren song' attraction, all automatic, run the whole house, no futzing, runs on clean natural gas, no gasoline to store and go stale, etc. But is it the end of the world to throw out some food once every ten years (and we haven't even had that happen)?

Now, comparing theses household units to the big diesel rigs - yep, big difference in size and cost. As you'd expect, there is a reason.

I know someone who had one installed for their small-business office which is out in the boonies a ways, and experiences outages occasionally. He was really impressed with what he got for the money. But the first time it kicked in for an over-night outage, all their computers (on their own small UPSs) were dead. This seemed odd, if the computers had their own UPSs, they should have been even more protected, right?

Well, I dug into it to help him out, and satisfy my own curiosity. In the mean time, he mentioned that the computers would kick back on when the genset was running and his well pump turned on! So now I have my Sherlock hat on. (Hang on, it all ties together)

Turns out, those UPSs for some reason, will go to battery if they see the 60Hz frequency drift just a little. Well, these cheaper gensets don't hold a steady frequency (more on this later). So it happened that the well pump loaded this thing just to the point that it ran close enough to 60Hz, that the UPSs said "OK, switch to line power". At other times, the computers were running on UPS battery, and that would be depleted in a couple hours.

So this wasn't good - he needs those computers up.

Now, more on this unsteady 60Hz - it is not just a matter of being 'sloppy', it is by design, to squeak out a little more advertised KW from a small engine/generator. How so?

When you load these down, you'd expect the engine to slow/bog down under the heavy load. But no, they built in some positive feedback to speed the engine up under load. So with a light load, the speed is low (maybe 54Hz, I forget exactly). But since the load is low, the voltage drops are small, so voltage output looks OK. Load it down, and it speeds up to ~66Hz, which is going to also raise the voltage output to compensate for the heavy load. So basically, some pretty clever trade-offs to get more power out under those conditions, but they can let it 'idle' a bit when loads are light. I'm guessing power out is related to the square of the velocity (too late/lazy to go look it up), so an overall 20% shift in speed could boost their power rating significantly.

It also turns out that the rated running hours on these are pretty low. I forget the number, but I seem to recall that if you actually had a couple weeks outage a few times a year, you'd be rebuilding (replacing?) these in just a few years. So it takes considerable more 'muscle' to provide rated power right at 60 Hz, w/o a lot of voltage droop, and do it for many hours before a rebuild is needed. It's a case of 'you get what you pay for', but it's probably good enough for many applications.

-ERD50

 

[ratto]

It also turns out that the rated running hours on these are pretty low. I forget the number, but I seem to recall that if you actually had a couple weeks outage a few times a year, you'd be rebuilding (replacing?) these in just a few years. So it takes considerable more 'muscle' to provide rated power right at 60 Hz, w/o a lot of voltage droop, and do it for many hours before a rebuild is needed. It's a case of 'you get what you pay for', but it's probably good enough for many applications.

That's what I heard as well, somewhere around 1000 hrs. If the 4-poles gen head is used, then the RPM can be dropped from 3600 to 1800, which will significantly extends genset lifetime (like 4 times).

 

[rescueme]

I found one of those permanently installed ones that can run off natural gas, if one is lucky to have that plumbed into the lot.

The unit you show can also run off propane if you don't have NG piped to your property (as we don't).

And no, it is not "too close" to the house. When we had a possible installation of the same unit, it would be outside our garage, close to the main electric panel located there, on the interior garage wall.