Do I need an Inverter or just a regular portable generator?

Discussion in 'Power Electronics' started by Moondoggy, Jun 24, 2016.

  1. Moondoggy

    Thread Starter New Member

    Jun 24, 2016
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    Can anyone help me determine if I need an inverter or just a portable generator?

    I live on the gulf coast of Florida in the US and we are sometimes impacted by hurricanes that knock out power for many days so I've been thinking about buying an emergency generator for my home. I cannot justify the expense of having a whole house, automatic backup system so I was thinking about buying about a 6000 watt portable generator from one of the big box home improvement centers and have an electrician wire in a bypass switch so I can connect the generator to my home. I was pretty set on what I wanted however I read an article about inverters and I then started questioning if I needed a inverter or just a portable generator. The article I read said that devices that have electronic circuit boards can be severely damaged if run off a regular generator and that one should buy an inverter instead.

    My concern is that I have sleep apnea and I have a CPAP device that I use at night to keep my airway open in case I momentarily stop breathing. Since this device pumps air up to the mask and regulates the air pressure I need I'm really concerned about the ruining this CPAP device off of a regular portable generator. In addition to my CPAP machine I was also concerned about my satellite TV receiver, my LED TV and my computer equipment being damaged as well.

    So can anyone know if I'm being overly concerned or whether I really need an inverter instead of a portable generator? Thanks.
     
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    A spinning rotor generator may not keep good freq control, and the voltage may wander, but it makes sinewave AC.
    Only the very expensive high end brand inverters put out sinewave AC. Most cheap ones are squarewave and the name brand are modified squarewave.
    If you need to run sensitive electronics, then a GOOD quality generator or a very high end, expensive sinewave inverter will both do the job. Both will cost about the same, you just choose which power source you will use to operate them.
    CNG/gasoline/diesel or solar/battery-powered.
     
  3. Moondoggy

    Thread Starter New Member

    Jun 24, 2016
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    Thanks for the reply. I understood your answer but I'm confused as to what you mean about a GOOD portable generator? I've looked at portable generators at some of the big box stores like Lowes and Home Depot and they all look the same to me so the question is.... How do you tell a GOOD one from one that not so good? In regard to the inverter, the only inverters that I can find that will allow you to make a 240v connection to my home are inverters made by Honda and Yamaha that will generate about 7000 watts. I'm assuming that these high end machines are the ones that you were referring to in your post. I would deeply appreciate learning how I can determine what a GOOD generator is so I can adequately protect my CPAP machine and other electronics.
     
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    Most all are good when new, but cheap units use cheap parts that soon fail or no longer work as intended. Cheap motors also use cheap parts and will wear out quickly and stop running long before they should.
    Cheap units become unreliable quickly, they break down early and frequently.
    Use good judgrment, but realize higher cost name brands are usually higher cost because they are not made out of the cheapest material the factory can source from China or India.
    Do not get a "grid-tie" inverter. They MUST have utility AC power in order to tie to the grid. If power goes out so will the grid tied inverter.
    Battery "off grid" powered inverters are what you use in a power black out.
    Batteries are expensive and wear out whether you use them or not.

    Hope this helps you decide.

    Personally I would suggest the natural gas powered generator with auto switch over

    Nothing else to buy and minimal standby maintenance is required to keep it ready to run.
     
  5. crutschow

    Expert

    Mar 14, 2008
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    This article supports the view that standard generators can damage electronic parts and virtually every powered device these days has some electronics. One poster said even his UPS units and microwave were damaged
    It suggests either to get an inverter type or an Automatic Voltage Regulator type generator.
    My opinion is that that's probably good advice, but I have no direct experience on that.

    In addition you might consider running the CPAP device from a UPS unit, if you aren't already, to keep it going if the power fails.
     
    Moondoggy likes this.
  6. gerty

    AAC Fanatic!

    Aug 30, 2007
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    They both have their pro's and con's .. Inverter depends on a fully charged battery, most have low voltage shut down, mine shuts off when batterty voltage hits 11 volts. solar panels can keep them topped off, but if it's a storm that knocked your power out it's likely to be overcast. And then there's night time, no solar, you need CPAP.

    Generator needs (should) be run from time to time to keep it up. TN, and others, have a law that any health care facility, hospital, must "exercise the generator for 1 hour a week". Fuel is something that's overlooked a lot. With today's fuel additives (ethanol) I have to use an additive to keep the gas from gelling when it's not used very often. I personally have a generator for backup power, that I probably haven't started in a year or so. I use Sta-Bil in it and so far zero problems.
    Pick your poison ...
     
  7. MrSoftware

    Active Member

    Oct 29, 2013
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    I've been through many hurricanes, I'll share my experience. In each hurricane, I was without power almost exactly 1 week. I have both an inverter and a generator, and here's my take on it.

    Inverters are good for TEMPORARY power. They rely on a battery, and the battery must be charged, which is difficult to do without power. An inverter will run a TV, a light and your refrigerator during the storm. If you've got 1 or 2 automotive sized batteries, they'll be dead within a few hours or a day or two depending on what you run with it.

    Generators require gas, which can be difficult to get after the storm, so think about how much gas you are comfortable storing, then assume that's all the gas you will have for a few days, and consider that when you choose a generator. I have a 4kw generator that is efficient. It's wired to my house and will run a window unit A/C, the refrigerator and household lights, computers, etc.. Overnight it uses less than 4gal of gas, probably 6-8 gal per 24-hours when I'm working from home. I try to get 30 gal before a storm, which gives me several days supply. Also be ready for generator maintenance. Most small units require oil changes every 50-100 hours, so if you're without power for a week you will be changing oil and oil filters.

    Things to consider; you get what you pay for with generators. Honda and Yamaha make stellar generators that are quiet and provide very clean power, but you're going to pay a lot more than the stuff you find at the local big box store. IMHO it's worth the price. Bigger generators burn more gas, which means you have to buy and store more gas. The inverter type are the quietest and most efficient (they don't have to maintain 3600rpm) and give very clean power, but most of them only give you 110v which can complicate wiring it directly to your house. Wiring to your house is much easier if the generator gives you 220v output. Also you have to maintain a generator. Either run it periodically, or store it completely empty of gas (carburetor too) and fog the motor with fogging oil so that you can store it long term.

    My personal take is have an inveter for during the storm, and generator for after the storm. Get a small reliable generator to power the essentials. Have a way to lock it up too, your powerless neighbors from the hood next door are more than eager to relieve you of your generator in the middle of the night while you're sleeping.

    Edit --> I would personally avoid natural gas or LP generators, unless you've got your own private very big tank. Houses (and infrastructure) in my area were built years before LP generators were popular, and I suspect when everyone fires up their generators the gas lines won't be able to keep up with the demand. Plus you will be relying on an outside fuel source that you have no control over.
     
    Last edited: Jun 24, 2016
  8. Moondoggy

    Thread Starter New Member

    Jun 24, 2016
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    The inverter model that I am considering is the Honda EU7000is http://powerequipment.honda.com/generators/models/eu7000is which only runs on gasoline. There is no natural gas in the area in which I live so my only choice would be gasoline or propane and both have their storage challenges. As you will note in the spec's this particular model is the only model in their inverter lineup that has a 30A, 250V locking plug so that you can connect it to the house (after you have an electrician install a switch to prevent the backflow of electricity to the grid) and it is definitely expensive ($4000). But....... If there is risk of damaging ones electronics and devices such as my CPAP device that would be hard to replace in a disaster situation, I would certainly pay the price to protect everything. The thing that is bothering me overall however is that you can buy a generator from Walmart if you wish and nobody is going to mention anything the potential impact on electronics which either means that (A) there's not that big of a concern or (B) it's let the buyer beware and if something get damaged, tough luck. Either way, buying and owning a generator or inverter generator is expensive and I just don't want to blow it. Let me know if you think that the EU700is is the correct inverter if I want to go that route and if there's a generator that would offer equally good protection that you're aware of, please share that information as well. Thanks!!!!
     
  9. MrSoftware

    Active Member

    Oct 29, 2013
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    That's a big gen, my only concern would be fuel consumption and ease of moving it around. Being an inverter it will be much more efficient than non-inverter. But being fuel injected, it will probably do better with storage. Depending on what loads you want to run, you could combine one of the 3kw units with an auto transformer to get your 240v and connect it to your house. I haven't done this myself, but this is what I was considering doing to replace my 4kw unit with a newer quieter unit.

    In my personal experience, I've never had dirty electricity from a generator "damage" anything. We did have a 5kw Coleman at work (home depot special) and the UPS's there would not come online with that generator without a lot of fiddling to turn down their sensitivity. Apparently the power from it was pretty dirty. As with utility power, keep anything truly valuable or sensitive plugged into a UPS even when on generator power.

    Food for thought; for the price you're shopping, you could also consider a pair of the 2kw Honda units. You would be close to 1/2 the price, and they can be run in parallel to give you 4kw. Combined with an auto transformer would make a nice hookup to your house. Plus you have 2 small portable units that could be run individually, such as overnight when load is minimal, with very little fuel consumption. There are 6 gallon external fuel tank kits for them, and those things are QUIET.

    In regards to the Honda you are shopping, if the fuel demands and the weight/size suit your needs then IMHO anyway it's a solid choice and will probably be overkill as far as output, unless you want to run your water heater, clothes dryer, etc..
     
  10. Moondoggy

    Thread Starter New Member

    Jun 24, 2016
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    Thanks you so much for the link to the article as that was exactly the information I was looking for. Just to confirm I did an online chat with a Generac sales rep and he specifically stated that only their XP Professional series generators with "TruePower Technology would meet my needs.
     
  11. ian field

    Distinguished Member

    Oct 27, 2012
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    An inverter usually means lead acid batteries - they require care, especially if used infrequently.

    If they're left discharged for any length of time, they sulphate - game over!

    There may be inverters with lithium batteries coming onto the market - I'd expect them to be less labour intensive.

    There's always the possibility of the starter battery on a generator set going flat - get one that can be hand cranked.
     
  12. MrSoftware

    Active Member

    Oct 29, 2013
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    Just for the Generac reference above; I have a Generac 4000XL that I've had for many years. It has been reliable and fuel efficient and electronics run just fine with it (I worked from home running my home PC's and their UPS's with it), but florescent lights flicker a little with it so I know the power output isn't perfect. I ran the same lights from a buddies Honda 2kw inverter and the lights didn't flicker at all. Next time I'm opting for a Honda or Yamaha.
     
  13. ian field

    Distinguished Member

    Oct 27, 2012
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    Which reminds me of something I forgot in my post - some inverters produce a "modified sinewave", most things work OK - but problems are possible.
     
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