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Do I need another transfer switch for another backup Generator.

Do I need another transfer switch for another backup Generator.

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  #1  
Old 11-02-19, 03:34 PM
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Do I need another transfer switch for another backup Generator.

Hello.

I have a large propane backup generator that is large enough to run my entire house for a limited time however the problem is we need an onsite propane tank that only hold enough fuel to run the generator for about a day.

Last hurricane, we were out of power for over 2 weeks and eventually had to purchased a smaller 6,000 KW generator that runs on gas. We had to run extension cords to temporary windows AC while our food spoiled in the refrigerator.

What I would like to do is add the smaller generator as a backup generator to my larger backup generator. So when I run out of fuel on my whole house generator, I would like to switch over to the smaller 6,000KW gas generator hooked into my house to run my refrigerator, few windows AC, air pump for my aquariums.

I already have a transfer switch which will disconnect the power utility from my house and switch over to my whole house generator. However, what would I need to connect the smaller generator to my entire house?

Do I need another transfer switch or can I use my existing transfer switch?

Can I plug in my secondary smaller generator to the same circuit as my current generator is on? So that if I run out of propane, I can just connect and turn on the smaller generator while limited the house circuits to fit the power output of the smaller generator?

Thanks

 
  #2  
Old 11-02-19, 04:03 PM
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The answer is no. You don't provide enough info as to why you don't have or get a larger propane tank, like 500 gallons. How many 2 week outages can you remember at your location?
 
  #3  
Old 11-02-19, 05:56 PM
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I suggest getting a larger or install additional propane tank as well.

If you must use a portable generator, I suggest adding a manual transfer switch that can transfer individual circuits.
https://www.homedepot.com/p/Reliance...0CRK/205793178
Something like this. (there 6 circuit one as well if that is all you need).

This goes after your main panel and allows you to switch circuits you need individually.
 
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  #4  
Old 11-02-19, 09:51 PM
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If your existing generator uses a plug to connect to the house you can simply unplug it and plug in the gas unit. You will of course have to limit the things you have running so as not to trip the smaller generator breaker.
 
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  #5  
Old 11-03-19, 12:06 PM
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If your existing generator uses a plug to connect to the house you can simply unplug it and plug in the gas unit. You will of course have to limit the things you have running so as not to trip the smaller generator breaker.
Existing generator is hardwired into the house with no plug. There is a large manual transfer switch which looks like something from the frankenstein movie.
 
  #6  
Old 11-03-19, 12:49 PM
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If you must use a portable generator, I suggest adding a manual transfer switch that can transfer individual circuits.
https://www.homedepot.com/p/Reliance...0CRK/205793178
Something like this. (there 6 circuit one as well if that is all you need).
If I already have a manual transfer switch, why would I need a second manual transfer switch? Also, why would I only want to power individual circuits vs powering the entire house but turn off 100% of the circuits to begin with and slowly 1 by 1, switch on only the individual circuits required at the time?

For example, I may want to run the refrigerator while I am out of the house then when I get back, turn off the refrigerator and turn on a small window Air condition unit. Stuff like that.

I may want to power different things at different times. This might also allow me the flexibility to upgrade my portable generator to something larger down the road.

My current whole house generator is extremely old and impossible to find parts for. The manufacturer no longer exist. During the last Hurricane, the water pump malfunctioned and the only replacement was from these government contractors types companies and they wanted like $15,000 for a new water pump when it would cost about that to buy a brand new whole house generator.
The generator is also larger then what my house needs and as a result will burn out the propane very quickly. During last Huricane, it was impossible to get propane delivered but much easier to buy regular gas in the aftermath.

Thanks.
 
  #7  
Old 11-03-19, 12:52 PM
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You will need another switch to disconnect gen#1 and connect gen#2. It can't be possible to connect them both at the same time.
 
  #8  
Old 11-03-19, 02:19 PM
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You will need another switch to disconnect gen#1 and connect gen#2. It can't be possible to connect them both at the same time.
Even if Generator #1 is not running when generator #2 is hooked up?

Generator #1 is hardwired into the entire house from the manual transfer switch.

Are you saying that if I connect generator #2 (even if generator #1 if off), the power will back feed into Generator #1 and cause damage or something?


Thanks.
 
  #9  
Old 11-03-19, 03:00 PM
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I am saying it needs to be impossible to connect them both at the same time. You can't count on someone knowing they can't run them both at the same time.
Backfeeding the other generator would also be an issue.
 
  #10  
Old 11-03-19, 05:23 PM
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Is there a reason why you can't operate the whole house standby generator on a periodic basis rather than continuous to extend the fuel supply. In my opinion you should be looking at purchasing a whole house standby generator matched to the house loads with an automatic transfer switch. With proper maintenance, all your concerns are gone. You don't have to be home to start and connect a generator, your meat won't go bad, the A/C will keep you cool and the transfer back to utility power is seamless.
 
  #11  
Old 11-06-19, 03:31 AM
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I am saying it needs to be impossible to connect them both at the same time. You can't count on someone knowing they can't run them both at the same time.
Backfeeding the other generator would also be an issue.
No one is going to connect both generators at the same time.

The secondary backup generator is not going to be accidentally turned on.

Is there like a 1 way valve for electric that will allow both generators to produce power but not have it back feed into it?

Thanks.
 
  #12  
Old 11-06-19, 05:36 AM
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No one is going to connect both generators at the same time.

The secondary backup generator is not going to be accidentally turned on.
Can you absolutely, unequivocally, be sure beyond a shadow of a doubt?
You can't guaranty that. The experts on this forum have answered your question, but you refuse to listen. What you want to do is not to code and is unsafe!

Suppose you get injured, and a neighbor or relative, or even a stranger tries to use your generator hook up. Will they be absolutely certain that they won't try to turn on both gens?

Your easiest and I suspect least expensive idea is response #4 JOED, change the hard wired unit to a plug in unit.
 
  #13  
Old 11-06-19, 03:31 PM
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Can you absolutely, unequivocally, be sure beyond a shadow of a doubt?
You can't guaranty that. The experts on this forum have answered your question, but you refuse to listen. What you want to do is not to code and is unsafe!

Suppose you get injured, and a neighbor or relative, or even a stranger tries to use your generator hook up. Will they be absolutely certain that they won't try to turn on both gens?

Your easiest and I suspect least expensive idea is response #4 JOED, change the hard wired unit to a plug in unit.
I can guarantee it. I think you may have the impressionism that I have generators side by side ready to go on the push of a button and some neighbor might bump into and turn on.

In reality, it would be easier to accidentally launch a nuclear missile then to turn on even 1 of these generators let alone 2 of them.

Primary generator need a large car battery to be connected to it. coolant added, then the garage door must be manually open to allow the airflow required for such a large engine, then it must run for 10 minutes to warm up and unlocked a large manual transfer switch about the size of the one used in the Frankenstein movie. and an extraordinary amount of pressure applied to move it. When you finally move it, it will first go into the neutral position which shuts off all power. Grd/generator,etc.. Then it must be pulled straight down to connect to the generator side. This is not something that you are going to accidentally do.

To connect the secondary generator which is currently mothballed in the basement. It would first have to be found under a pile of boxes, it would have to be somehow moved all the way upstairs and hundred of feet away without having wheels and weighing a ton. You would then have to find some gasoline which we don't have. So like siphon it from a car or something. Then you would have to find engine oil and a funnel and add it to the generator then you would have to connect it to an outlet in the garage along with a primary generator running so loud that you can hear it and feel it though the entire house even neighbor houses can hear and feel it.

Then you would have to manually pull start the engine since it has no electric start several times .

It would be more likely to to drown in my fish tank then having someone randomly doing all this.

You want to talk dangerous? My power company exposed power equipment in an area that kids play near. There is a steel door with a lock on it but the hinges have rusted off and the door if laying flat on the ground with the equipment room completely exposed with buzzing electrics inside.

So to answer your question. Yes, I can guarantee it 100% that both generators are not going to be switched on and the same time. Also, I am guessing I can also get a generator input that would require a lock and key to open.

Is that the only reason why you would need another transfer switch is to prevent 2 generators from running at the same time?
 
  #14  
Old 11-06-19, 03:36 PM
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If it is possible to do it then it is against code.
 
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  #15  
Old 11-06-19, 04:18 PM
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Electrical codes are imposed to minimize the chance of death, loss of limb , loss of property, etc. due to improper use of electricity in a dwelling. If you know what your doing, wing it. But before you do and out of consideration for the kids who play in your area, call the power company to report the problem you see with their equipment. Thank you.
 
  #16  
Old 11-06-19, 05:19 PM
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The code requires to make it impossible to connect 2 or more power sources at the same time.

If you are willing to ignore the code and take a chance with associated risk, that is up to you.

You will still need a way to disconnect generator inlet while electricity is being supplied by the main generator or electric company. This is one of the reason why interlock or transfer switch is required. Generator inlet has male prong and there is a risk of electrocution.
 
  #17  
Old 11-09-19, 08:47 AM
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To connect the secondary generator which is currently mothballed in the basement. It would first have to be found under a pile of boxes, it would have to be somehow moved all the way upstairs and hundred of feet away without having wheels and weighing a ton.
Now if you did have the urgent need to get and connect the secondary generator, you need to guarantee that the secondary generator, still out in the open, cannot remain connected no matter how hard you tried, when you switch back to the first generator or utility power.

Only a proper transfer mechanism can guarantee that.

Exception, if you start dismantling or damaging a panel, revealing access to wires and terminals and lugs and other possibly energized parts inside, then all bets are off.
 
 

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