How to Choose a Generator?

[JimPghPA]

Originally Posted By: Donald
Originally Posted By: TFB1
Originally Posted By: JimPghPA

Also note that if your water heater is a 240 volt unit and you run it on 120 volts, the power the heater would draw would be only 1/4 of normal. The heating time would be FOUR TIMES NORMAL. This is because at 120 volts the curent draw would be half that of normal. And since the voltage is only 120 (half that of normal) and the wattage is AMPS x VOLTS the wattage draw would be 1/2 x 1/2 = 1/4. This is if you ran a 240 volt water heater on 120 volts and left both heating elements conected.

If you ran a 240 volt water heater on 120 volts and you disconected the uper element then the power draw would be 1/8 that of normal. The heating time would also be EIGHT TIMES NORMAL.


In all the water heaters I've seen, if you disconnect the upper element you'll eventually only have cold water... That's because both elements never are on at the same time...

As long at the upper portion of the tank is warm enough to keep the thermostat from activating the upper element, the lower element does all the heating... When the upper element is on, it's thermostat shuts off the lower and returns it to duty only when the upper portion of the tank is heated... If the lower element is disconnected, the upper will keep cycling till the entire tank is approx same temp, but you'll have a limited supply of hot water in higher demand usage...

I bought my like new Homelite 4400 watt generator at the DAV thrift store $300, I can alternate loads if necessary when I need to use it...


You will never end up with all cold water if the upper element is disconnected. Heat rises so the bottom element can do all the heating, but if you should run out, the recovery for maybe the upper 1/3 will be longer if the lower one does the heating than the upper.

I'll bet many people have broken upper elements for years and never know it. If the bottom one fails you will know it however.

I have a cottage sized electric water heater at my cottage, its 110V and one element. Works fine for one or two showers, but its a cottage.

In most cases, people should forget about items that produce much heat when running on a generator. Unless of course you get a monster.

In my case, my oil burner takes care of the hot water and I have a "hot water maker" that could probably do many showers at once for weeks straight until I ran out of oil.


TFB1 has a valid point. If the wiring is such that the upper thermostat applies power to the lower thermostat and lower heating element ONLY when the upper thermostat shuts down the upper heating element, then simply disconnecting the upper element would result in a total shut down of the water heater, because the thermostat for the upper element would never be satisfied (ie go to the position of supplying power to the lower element, because the upper element had gotten the upper portion hot enough), and there-fore the upper thermostat would prevent the loser element from ever working.

To disconnect the upper element and still have the lower element work, you would have to re-wire the power to by-pass the upper thermostat supplying power to the lower, and there would be no point in doing that anyhow if the upper and lower can not come on at the same time, unless you were going for the additional reduction of current draw by putting both elements in series.

It ain't rocket science, but is is a little trickier than having both elements being independent with each having only its own thermostat.

 

[user52165]

Is this a generator or water heater thread?

 

[Gebo]

Just so you all know, I've decided to get a 5000+ generator. I'm gonna have it wired to my breaker box. Thanks for all your help!

 

[JimPghPA]

Originally Posted By: JimPghPA
The starting surge for very old refrigerators and very old freezers in unbelievably much higher than more recent ones.

We have a 60 year old freezer that is the size of a large refrigerator and it draws 17.5 Amps on start up and 400 Watts to run. Our new refrigerator/freezer draws 6 Amps on start up and 110 watts running (155 watts running with the door open and light on).

When it comes to choosing a generator there are two basic types: non inverter that run at 3600 RPMs all the time, and usually can supply significantly more than their full time running capacity for a brief amount of time such as when the compressor on a refrigerator or a freezer starts, because these generators run at 3600 RPMs all the time so they can make 60 Hertz power they drink about one gallon each hour for a 8000 Watt unit (you can get a good estimate of how much a 3600 RPM unit will drink by looking at what percent of 8000 watts it is, such as 4000 watt will drink ½ gallon per hour, 1200 watt will drink 1.5 gallons per hour, exc.), the other type of generator is an inverter units that change the RPMs with respect to electric load. The inverter units get much longer run times for each gallon of gas and they are quiet compared to the non inverter type. However inverter generator cost much more, and they will not put out more than they are rated for even for a brief amount of time such as when a motor on a refrigerator or freezer starts.

BTW one of the worst things you could do would be to allow more than one motor to start at the same time, such as throwing a breaker that would bring up all three of the units you talked about at the same time.


That should have read 12000 watts, not 1200 watts.

 

[gd9704]

Quote:


Stay away from the cheaper clones.

Get a Honda EU3000 or EU6500 Inverter, I've had several over the years and currently use any of the EUxxxx series depending on the location, need, load. Craigslist is a good place to start.


Agreed. I'd rather spend my money on a used Honda EU series or Yamaha EF series generator over a HF cheapie.

The racket of non-inverter type gensets wear on my ears in short order...also, inverter generators don't run at a constant 3600 rpm to make power--less engine wear.

 

[eljefino]

Who would sell a used inverter generator? They're the bees knees and resale is good. I'd be wary of them being stolen, frankly.

Personally I would get a new invertor if getting that style; the technology is spreading and prices are dropping. I'd be afraid of getting one with a "million" hours on it, used. They are generators for the serious set. Of course you could get lucky and find a yuppie owned one they got for camping that they rarely used.

My three 3600 RPM genertors are quite quiet; one is notably rated at 67 dB and all have sizeable mufflers. The nasty briggs construction site generator with "soup can stuffed with steel wool" muffler is only one style but gives them all a bad rap. In an outage I can hear the neighbors' generators over my own!

 

[henni]

CL has inverters for sale almost all the time and with hondas you have LED display for hours runtime.

Last 7000w honda had 1 hour on display and even protective plastic on handles, engine and wheels in factory box new condition. It had been stored by Marina for hurricane season and sat under tarp for a year. Started first crank but needed new AGM battery which was close to 3 years since manufacture date, picked up one from WW for 60.

 

[Donald]

Inverter or plain 3600 RPM type, the gas is an issue. If you are not going to go the trouble of stockpiling some gas, stabilizing it, rotating it, then the power will fail and you will have no gas and will be draining your lawn mower for gas. Which will get you 30 minutes of time.

Propane is the way to go.