Portable Generator

[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.