I would like to set up a back up power system for times when city power is down for extended periods. I need enough power to run our side-by-side ref rigerator/freezer, a small fan, and charge a couple iPhones and a laptop co mputer. The tag on the inside of the refrigerator says Full Load Amp: 6.5. How much more will the motor draw at startup? Do I need to size for star tup or normal operating conditions?
This model supposedly uses 617 kw-hours/year. Is this information relevant in sizing a backup system? If so, how can I use it?
I need enough power to run our side-by-side refrigerator/freezer, a small fan, and charge a couple iPhones and a laptop computer.
The tag on the inside of the refrigerator says Full Load Amp: 6.5. How much more will the motor draw at startup? Do I need to size for startup or normal operating conditions?
My generator says 5500 running watts and 7350 start-up watts. I've had it running handling refrigerator, 2 small freezers, furnace and well along with enough power for some lights, TV and computer.
You did not say what kind of system you want but I doubt battery would handle your needs.
You may be able to get a high output true sine wave UPS and attach it to several BFB's, "Big Freaking Batteries" that will run the fridge for a while or find a 5kw contractor's genset you can roll out of the garage or utility building so the exhaust fumes don't get into your home and power thing with it. ^_^
I don't know of a use. Have to chat with your neighbors, see what works. Is the natural gas available, and is it dependable? You thinking permanant backup generator?
I'd like a wired in generator, but no money for that. I do have a portable, which is some help.
so you probably need at least a 1500-2000W UPS or generator because of startup load (minimum)
Now if you go with a UPS keep in mind that let's say you want to run this for 24 hours - even at a 50% duty cycle that's 6.5 * 12 = 30 Ah at
120V so 300Ah at 12V so that's six car battery sized lead-acid batteries right there, without accounting for inverter losses and other inefficiencies. Let's call it eight. Really, ten is probably a better estimate - and that's just to run the fridge for one day with a little overhead.
A portable gas powered generator will take up less space, cost less, etc... unless you already have a PV system or something in place I don't see the benefit of going with batteries.
A typical tower or rack-mount UPS that just plugs into a 15A wall socket may be rated at 1000-1500VA but that alone will be costly, and probably comes with two 7-9.2Ah 12V SLA batteries. It "may" run a fridge but it'd have to be an expensive true sine wave unit (~$4-500) to keep the motor happy and that is really not what it's intended to do, so good luck making a warranty claim if it fails. Many people think that "clean" power is most important for PCs and other electronics, not true! They can handle pretty dirty power as long as no voltage surges come on the line that are too big for the built-in MOVs of the device's power supply to handle. Electric motors, on the other hand, really don't like dirty power. And even if your expensive true sine wave UPS works flawlessly, the batteries supplied will be exhausted in a couple hours, nowhere near an "extended power outage." You'd definitely be looking for a $$$ commercial setup for your suggested usage, probably weighing enough that it would have to be installed on the bottom floor (assuming slab or foundation; if you have a crawl space fuhgeddaboutit) and as large as your average refrigerator itself.
Spend some money on a Kill-A-Watt or functional equivalent and measure it.
Reason: startup requirements vary a great deal depending on how old a refrigerator or freezer is and (I'm guessing) from make/model to make/model).
We have an old refrigerator in the kitchen that wants some ungodly amount of watts - can't recall how many - and it tends to make our automated transfer switch shed loads to allow startup by our little 2KW generator.
OTOH, the new refrigerator and the new freezer in the garage don't pull much more at startup than they do steady state - something under 150 watts.
How citified is "city"?.... i.e. do you have secure space to leave a generator far enough from the house for safety fume-wise?
If that's all you want to run, something like a Honda EU2000 or the Yamaha equivalent would work well and be quiet. There is also a Champion equivalent that is cheaper and seems to get good reviews. On an EU2000 you'd likely get 8 hours on a fueling, and there are a number of extended run fuel tank options available.
I doubt the typical refrigerator or freezer is running anywhere near 50% of the time. Especially if you know it's on backup and only open the doors as little as possible. The 617 Kwh per year number would seem to support that it's running just a small fraction of the time.
Let's call it eight. Really, ten is probably a better
I guess the benefits would be:
Someone doesn't need to be there to start it. No noise
The disadvantages:
For the same money you could probably have a generator with significantly more capacity
The inverter only lasts as long as the batteries. A generator will run indefinitely as long as you put gas in it.
The batteries don't last forever.
I would tend to go with about a 3000 - 3500W generator. More than enough to run what he has so he can plug in a TV, etc too.
But I'd also re-evaluate the need for one at all. The typical fridge/freezer full of stuff will last a couple of days without power, if you leave the doors closed. You can have an ice chest available, open the fridge once to get the stuff you're going to need for a couple days, then leave the fridge closed. Also, if you know a hurricane or something is coming, you can put extra containers of water into a freezer 24hr or more in advance. The more thermal masss, the longer it will last.
The lights, there are LED battery lanterns and such available. The phone and laptop can be charged in the car.
I don't know about the motor in a refrigerator, but the motors where I worked were driven from inverters that did not resemble pure sine waves. The eairly inverters used stepped wave forms. Looked like a stair case gong up 3 steps and down 3 steps for each half cycle. The later inverters put out a waveform that looked like pure trash but were beter. You could sometimes hear the motors 'sing' at high frequencies.
They were used on everything from less than 1 HP to 300 HP motors.
The last time I was required to use a true sine wave UPS was when I installed an Intertel phone system for a business. It's been years but I don't think the phone system had a switching power supply so it needed clean power to keep it from sounding like a buzz-saw. ^_^
I've seen them spec'd for CCTV, intrusion detection etc. systems... but I'm not sure that it's really the true sine wave that's the driver, but the requirement for a "true online" or double-conversion (e.g. not line-interactive type) - most that are true online are also true sine wave. Or it could be both. It's been a while since I've read one of those specs.
is down for extended periods. I need enough power to run our side-by-side refrigerator/freezer, a small fan, and charge a couple iPhones and a laptop computer. The tag on the inside of the refrigerator says Full Load Amp: 6 .5. How much more will the motor draw at startup? Do I need to size for s tartup or normal operating conditions?
ant in sizing a backup system? If so, how can I use it?
I second that observation, that new ones don't pull much starting current. I monitored a 3 year old freezer running on a gener ator during Sandy with a Kill-a-Watt. It might have been 200 watts at most at start-up, then quickly came down to under 100 watts.
That kill-a-watt is highly recommended for monitoring how much load you putting on the generator during an outage. I had it wired up so I measured the load going to the generator. Actually the neighbor's generator. I was shocked at how much we ran off that puppy. And we had probably 150 ft of extension cord between the generator and my house. And then another
100 ft of wire maybe to the furthest point in my house.
The generator was just 4KW, I think. Just one of those cheapos. It supplied power for 4 fridge/freezers, two gas furnaces, (actually 3 because I only put one on at a time), some cfl lights, etc. The neighbor even had a resistance heater running off it, that's the only time I heard the thing surge. I showed him how to get his gas furnace going, then he didn't need it.
And the whole time I was watching the kill-a-watt, we had close to 120V all the time at the end of that ext cord.
I previously would have thought like 7 or 8KW was a good size. But now I'd say 5KW is plenty, unless you need central airconditioning or some other big load. Even the furnace was only like 300W.
And as I said before, for what he's talking about, how critical is a generator? A fridge/freezer will easily go through a 2 day outage if you don't open the doors. Get what you need, put it in a small ice chest. For lights you have LED lanterns now that last a long time. Phone/laptop yo u can charge in the car. Not sure how useful the laptop even is, with a big power outage cable/internet is likely to be out too.
I got a week out of my freezer during Sandy. Some stuff had just started to melt. I did put extra jugs of water in to freeze a couple days before. And on two days later in the week, I swapped those out for new frozen ones from a friends freezer. And then at the end of it all, it comes down to probabilities. If there is only a very small chance that you're gonna lose food in a freezer from an outage that last many days, how often does that happen? And if you lose $300 in food if and when it does, is it worth the hassle of having a generator and gas sitting around, etc?
For something like a refrigerator you will really need a generator.
However, in the event of a power failure...if you DO NOT open the doors your food will stay good for up to 24 hours or more. (Depending on ambient temperature of course.)
s down for extended periods. I need enough power to run our side-by-side r efrigerator/freezer, a small fan, and charge a couple iPhones and a laptop computer. The tag on the inside of the refrigerator says Full Load Amp: 6.
How much more will the motor draw at startup? Do I need to size for st artup or normal operating conditions?
nt in sizing a backup system? If so, how can I use it?
I have a 6,500 watt portable, gas powered generator for power outages. I ra n a Romex line from the generator, where it plugs into the generator outlet , to an outlet box I installed near where the refrigerator and freezer plug into the house current. When the power goes out, I start the generator, un plug the appliances from the house outlet and plug them into the generator outlet. It's essentially a permanently placed extension cord. There are sim ilar arrangements for the pump (we have a well), boiler, etc. We have LED r echargeable lanterns plugged in around the house so they're always charged and ready for an outage.
I looked into an auto-on, whole house back-up generator but that came to ab out $15,000 installed, so I'm sticking with my current setup.
Heck most of the electronic electronic equipment I've installed in the past 25 years has had a switching power supply which didn't care WTF you fed it with. One of these days you will be able to walk across a shag carpet and use the static electricity to power your implanted link. ^_^
Just for the record, I've had power failures up to 3 days and have never lost any food during one. Even while the news is full of stories about throwing food away.
I open the fridge and freezer doors as little as possible and I keep them open probably no more than 10 seconds, unless it takes longer than that to remove the food.
It's still cold in the freezer when the power is restored and quite cold where the boxes are stored with other food above and next to it.
I eat, or cook and eat, the things that have the least shelf life. I monitor the ice cream to see how quickly i have to eat it. Even though it doesn't spoil until days after it's a liquid, I don't like to eat it after it's liquid.
It's just me living here, but I usually keep the fridge and freezer pretty full. If there was more than one person here, I'd have even less trouble eating the food before it's bad.
If I were having trouble doing that, I'd cook some of the food, especially unfrozen meat, becaues it keeps longer at the same temp when it's cooked. I have an electric stove, but my outdoor grill runs on propane.
Somebody in another group observed the distinction between "Lifeboat" and "Cruise Ship" when it comes to choosing a generator.
I went the "Lifeboat" route with a Honda EU2000 and an APC UTS-6 smart transfer switch. It serves most of the circuits in our house, but not all.... but what it serves are sufficient for reasonable comfort given that AC is not going to happen.
Fuel consumption was one concern. After that was the ability to pick the thing up, throw it in a car, and use it somewhere else.
The neighbor gets about one hour out of his 5KW's 5-gallon tank. We get more like five hours out of our EU2000's one-gallon tank.
But we also have natural gas. If I were doing it over, I'd have to consider "Cruise Ship": a higher-capacity generator, maybe on a slab somewhere in the yard, running on nat gas. No fuel storage issues, no fuel availability concerns. Yes, it costs more per hour to run, but how often do we get outages? Dunno what the cost would be, but I suspect I might suffer some sticker shock...
But even if I stuck with gas, I would get a Honda EU3000 instead of the
2000. It's heavier, but still manageable given a hand truck and, if I am to believe the numbers somebody posted somewhere, it's slightly more economical at the 800-1200 watts that our house seems to run at much of the time. Also, the to easily pick up the EU2000 cuts both ways when/if one has the wrong kind of people wandering the neighborhood...
I'm not sure that's true. NG is fairly cheap. You'd have to look at the fuel consumption specs and the cost of the NG.
Dunno what the cost would be, but I
The big sticker shock is if you buy a whole house standy unit and then have to have it professionally installed, with transfer panel installed, gas lines run, etc.
There are conversion kits available that will convert common portable generator engines to nat gas. Some are permanent and others allow switching back and forth. The kits cost maybe $250.
And instead of running wiring to the appliances, like you did, I would install an inlet at the panel and get one of the lockout kits for the panel. It prevents the main and the breaker that the inlet is connected to from both being on at the same time. They are just a metal slide bracket, but they are still charging $175 or so for them. Then you use one heavy extension cord from the generator to the inlet and use the breakers to manage which loads you want on. I might consider putting an ammeter between the inlet and the panel to know exactly how much you're pulling too.
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