Portable Generator

[Larry Caldwell]

Electric hot water heater is a real killer and will pull 4.5KW all by itself.

That depends on the water heater. Mine is a 3600 watt water heater, which doesn't recover as fast as the 4500 watt tanks, but is easier to run on a generator. You can replace the heating elements in a water heater with lower wattage elements. They are all interchangeable.

Once you have a tank of hot water, you can shut it off and turn the well pump on to take a shower.

 

[jinjimbob]

That depends on the water heater. Mine is a 3600 watt water heater, which doesn't recover as fast as the 4500 watt tanks, but is easier to run on a generator. You can replace the heating elements in a water heater with lower wattage elements. They are all interchangeable.

Once you have a tank of hot water, you can shut it off and turn the well pump on to take a shower.

This is one reason I got a heat pump water heater than can run in heat pump only mode which uses less than 550 W.

 

[Skyco]

Some cars (I don't know all but Dodge minivans do) have a high drain line coming from the tank. On my van it was above the rear axle on one side and had a plastic cap on it. They figure that with a pump in the tank you need a way to drain the tank to replace the pump. You can start a siphon and drain the gas. Just something to look for. You can always use a pick on your ex's boy friend's tanks and catch it with a funnel

Ex boy friend? Now wait just a dang minute...boy friend? I hope that was addressed to financegal and not ME:laughing:

Interesting about the drain line..didn't know that.
My Honda Civic I keep around actually has a drain plug in the tank..or so the manual says. I'm not real keen on pulling a plug and here comes all the gas with no way to control it, especially while laying under a car!
One spark and....
I'd like to periodically cycle the gas out of that car since it is almost never driven..I've started looking into ways to disconnect at the fuel filter on the firewall and jump something to make the pump run..same idea of course would work for emergency generator supply.

 

[dcyrilc]

Ex boy friend? Now wait just a dang minute...boy friend? I hope that was addressed to financegal and not ME:laughing:

Interesting about the drain line..didn't know that.
My Honda Civic I keep around actually has a drain plug in the tank..or so the manual says. I'm not real keen on pulling a plug and here comes all the gas with no way to control it, especially while laying under a car!
One spark and....
I'd like to periodically cycle the gas out of that car since it is almost never driven..I've started looking into ways to disconnect at the fuel filter on the firewall and jump something to make the pump run..same idea of course would work for emergency generator supply.

What if you ran the car nearly out of gas, then pulled the drain plug and replaced it with a petcock valve or something similar. That would allow you to drain it with control to cycle the gas. You might even be able to put the drain plug back into the bottom of the valve for additional safety. Just a thought.

 

[Financegal]

Ex boy friend? Now wait just a dang minute...boy friend? I hope that was addressed to financegal and not ME:laughing:

Don't think there haven't been times I'd have liked to do something as sinister to punish BF but the voice of reason always kicks in just in time:laughing:

 

[BobRip]

Ex boy friend? Now wait just a dang minute...boy friend? I hope that was addressed to financegal and not ME:laughing:

That was supposed to be your ex wife's boyfriend. Sorry for the confusion.

 

[BobRip]

That depends on the water heater. Mine is a 3600 watt water heater, which doesn't recover as fast as the 4500 watt tanks, but is easier to run on a generator. You can replace the heating elements in a water heater with lower wattage elements. They are all interchangeable.

Once you have a tank of hot water, you can shut it off and turn the well pump on to take a shower.

If you run the hot water heater off of 120 instead of 240 it will pull only 1/4 of the power. It will take 4 times as long to heat, but you can do it with a small generator. See your electrician to do this.

 

[dcyrilc]

If you run the hot water heater off of 120 instead of 240 it will pull only 1/4 of the power. It will take 4 times as long to heat, but you can do it with a small generator. See your electrician to do this.

Not true. Heating elements are rated in watts which are a measurement of the power it will consume to operate. Watts = Volts x Amps. Attempting to run a 240 volt heating element off 120 volts will double the current draw and most likely overload the wiring. A 4000 watt element will draw 4000 watts regardless of the voltage applied.

 

[BobRip]

Not true. Heating elements are rated in watts which are a measurement of the power it will consume to operate. Watts = Volts x Amps. Attempting to run a 240 volt heating element off 120 volts will double the current draw and most likely overload the wiring. A 4000 watt element will draw 4000 watts regardless of the voltage applied.

Heaters are rated at watts at a given voltage, not a fixed watts at any voltage. If what you say is true then they would put off 4000 watts at 1 volt or even 0.1 volt. They are just a coil of wire and do not vary their resistance (very much) to compensate for voltage.

The resistance is pretty fixed (it does go up some with increasing voltage, but not much in this application)

Power = V^2/R (Look this up if needed)
R = fixed
240^2 = 57,600
120^2 = 14,400

14,400/57600 = 0.25

My electrical engineer degree is pretty old, but this has not changed much.

Light bulbs are also rated at wattage. They do get dimmer when the voltage drops. If they pulled constant watts they would not get dimmer. Again it's watts at a given voltage.

 

[dcyrilc]

Heaters are rated at watts at a given voltage, not a fixed watts at any voltage. If what you say is true then they would put off 4000 watts at 1 volt or even 0.1 volt. They are just a coil of wire and do not vary their resistance (very much) to compensate for voltage.

The resistance is pretty fixed (it does go up some with increasing voltage, but not much in this application)

Power = V^2/R (Look this up if needed)
R = fixed
240^2 = 57,600
120^2 = 14,400

14,400/57600 = 0.25

My electrical engineer degree is pretty old, but this has not changed much.

Light bulbs are also rated at wattage. They do get dimmer when the voltage drops. If they pulled constant watts they would not get dimmer. Again it's watts at a given voltage.

Hmmm....

After 30+ years of being an electrician, this wouldn't be the first time I've been wrong. I'll have to check on this.

Until then, I'll have defer to the knowledge you have from your electrical degree.

 

[Travelover]

Hmmm....

After 30+ years of being an electrician, this wouldn't be the first time I've been wrong. I'll have to check on this.

Until then, I'll have defer to the knowledge you have from your electrical degree.

I'm a mechanical engineer, but I get the same calculation.

Voltage= Current times Resistance

If you cut voltage in half, then current also drops in half to make equation still valid, 'cause resistance stays the same.

Power (watts)= Voltage times Current.

Voltage and Current are both halved, so wattage is 1/4th of previous level

 

[Larry Caldwell]

To clarify this, a 3600 watt water heater element would indeed only draw 900 watts at 110 volts. You would have to disconnect it from the power panel and wire it directly to the generator to get this to work, and it might take 4 hours to heat a tank of water. Some emergency situations move slowly.

I try to prep for emergencies so things will be as simple as possible. Flip transfer switch. Start generator.

 

[BobRip]

Hmmm....

After 30+ years of being an electrician, this wouldn't be the first time I've been wrong. I'll have to check on this.

Until then, I'll have defer to the knowledge you have from your electrical degree.

Do check it out. You could actually measure it with your amp probe.
Sorry to bludgeon you with the degree. I also have played around with this stuff since I was six.

 

[BobRip]

To clarify this, a 3600 watt water heater element would indeed only draw 900 watts at 110 volts. You would have to disconnect it from the power panel and wire it directly to the generator to get this to work, and it might take 4 hours to heat a tank of water. Some emergency situations move slowly.

I try to prep for emergencies so things will be as simple as possible. Flip transfer switch. Start generator.

As a temporary thing if you are skilled at going in panels, you could take one of the leads off of the hot water heater breaker and connect it to neutral. This would give you 120 on the hot water heater.

 

[dcyrilc]

Do check it out. You could actually measure it with your amp probe.
Sorry to bludgeon you with the degree. I also have played around with this stuff since I was six.

As I said, not the first time I've been wrong in my life. Probably won't be the last either.:laughing:

 

[firefighter9208]

Instead of an automatic transfer switch ($$$) a lot of people use these. Generator InterLock Kit .

A handy chart on electrical usage:

Wattage Calculator


I have a Generac 5500/8500 watt portable. I have it wired to my house panel. I have 2 refrigerators and a deep freeze. I have to make sure to cut off the breakers to the 3 and manage them independently when I crank the generator. All three trying to start at one time (4500-5000 watts), along with other things in the house would overload the generator. Remember that a refrigerator/freezer will run about 12 hours a day. A freezer less if not opened.

I turn on the power to one of the refrigerators and let it run until it cuts off, then power up the 2nd and do the same. Then I turn on the breaker to the freezer.

I then go around the house turning off lights behind the kids and wife.

Chris

 

[BobRip]

Instead of an automatic transfer switch ($$$) a lot of people use these. Generator InterLock Kit .


I have a Generac 5500/8500 watt portable. I have it wired to my house panel. I have 2 refrigerators and a deep freeze. I have to make sure to cut off the breakers to the 3 and manage them independently when I crank the generator. All three trying to start at one time (4500-5000 watts), along with other things in the house would overload the generator. Remember that a refrigerator/freezer will run about 12 hours a day. A freezer less if not opened.

I turn on the power to one of the refrigerators and let it run until it cuts off, then power up the 2nd and do the same. Then I turn on the breaker to the freezer.

I then go around the house turning off lights behind the kids and wife.

Chris

I have one of the generator interlock devices. I made it myself since I did not know at the time that you could buy one.

On your refrigerators and freezer, I believe that you could run all three at the same time if you start one, wait 30 seconds, and then start the next. Start the largest one first. I would look at the nameplates on them to get the power, not a generic program. My 21 Cubic foot refrigerator pulls about 250 watts when running, except at defrost. Then it is about 900 watts. Defrost does not occur often.

 

[firefighter9208]

I have one of the generator interlock devices. I made it myself since I did not know at the time that you could buy one.

On your refrigerators and freezer, I believe that you could run all three at the same time if you start one, wait 30 seconds, and then start the next. Start the largest one first. I would look at the nameplates on them to get the power, not a generic program. My 21 Cubic foot refrigerator pulls about 250 watts when running, except at defrost. Then it is about 900 watts. Defrost does not occur often.

I do cycle them. When one cuts off I start the other. That way they are staggered and less likely to come on at the same time.

Chris

 

[BobRip]

I do cycle them. When one cuts off I start the other. That way they are staggered and less likely to come on at the same time.

Chris

Your method requires the generator to run longer. I find the refrigeration units force more run time than anything else. This forces the use of more gasoline. In a long power outage running out of gas can be a real problem.

I don't think you have to wait until the unit stops to start another, just wait a minute.

I now have solar hot water panels. Since I get most of the sunlight in the afternoon, I need to run the generator then. In the past this was the time I never ran the generator. I am hoping my inverter will handle this task.

 

[Larry Caldwell]

Your method requires the generator to run longer. I find the refrigeration units force more run time than anything else. This forces the use of more gasoline. In a long power outage running out of gas can be a real problem.

If you have warm weather outages, like a hurricane, then you need to keep the refrigerator running. For winter outages, I just put any perishable fresh food in the unheated garage. The chest freezer, in the same unheated space, will hold for days without power. It only needs to run once or twice a day at most.