New Generator Installation

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  #1  
Old 11-15-15, 12:11 PM
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New Generator Installation

Hello, I have a new generator that I would like to use for backup power in my home. The generator is a DuroMax XP10000e generator 8000 watt constant/10000 watt peak. I live in Cincinnati Ohio. I have a son that is on medical equipment in the home and I would like to use the generator as a backup mainly for his equipment. I have read that you can use a transfer switch or interlock device. While both may be helpful, I was thinking about setting it up on its own without feeding into the homes electric.

My plan is to use the 240v 50-amp outlet on the generator and use each of the 120v lines to create 120v outlets. I would like to feed the power from the generator to a sub panel only used by the generator. Then from that panel power 4 120v 15-amp outlets. I would use each 120v line from the generator to power 2 120v outlets. Each outlet would have a 15-amp breaker in the panel.

Here is my logic. The generator has 8000 watts of constant power. For the 240v outlet that means I can safely use about 33 watts. If I split the 240v to power into each of its 120v lines I should have 2 120v lines at a little over 30 amp each. Is this correct? Is this safe? Does anyone have any advice or concerns with this plan?

The generator will never connect to the power of my home. There will never be a backfeed. The outlets I install will be in the bedroom where my sonís equipment is located and we can easily start the generator and switch the power cords.

Thank you,
 
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  #2  
Old 11-15-15, 12:37 PM
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Welcome to the forums. I well know that, even in the great metropolis of Cincy, we get power outages from storms. Went through a week with the remnants of IKE a few years back and about seven hours earlier this year.

While I have a small Genny to just power the furnace blower and a TV and light or refrigerator,
with the size of your unit I would strongly suggest and automatic transfer switch.

That auto system will not cause back feed and you can have light in most rooms, TV, refrigerator and most home niceties. A big plus is that you will not have all that extra wiring, outlets etc.
 
  #3  
Old 11-15-15, 12:47 PM
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Thanks Goldstar. I guess my concern question would be the output of the generator. There are 4 outlets. 240v 50 amp, 120/240v 30 amp, 120v 30 amp, 120v 20 amp. Would I still use the 240v 50 amp power from the generator? Also given my math before I would only be able to power 4 15 amp circuits. I have about 24 circuits in the home. I would not be about to power the heat since it is electric. Does my logic make sense that I would only be able to power 4 circuits?
 
  #4  
Old 11-15-15, 01:15 PM
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What wattage does your sons equiptment draw?

Thats an awfully big generator.. To keep the windings balanced I would probably opt on using the 30 amp 120v outlet and switch the selector to the 120v position.

The 50 amp outlet will give you 25 amps per leg I believe...
 
  #5  
Old 11-15-15, 01:18 PM
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I couldn't find the full specs on your generator. I do not think it is proper to split the 240 outlet as you describe. I'm not an electrician, but the sparkys will pop up here soon. Your son's medical needs are not my business, but it seems like it must draw a lot of amps.
 
  #6  
Old 11-15-15, 01:27 PM
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Machine 1 5 amp
Machine 2 4 amp
Machine 3 5 amp
3 others that may or may not be on at the same time each less than 1 amp.

Everything is 120v so the max would be 17 or so for his must have equipment.

Another 12.5 amp for a heater and some additional for lights.

Based on this I would need between 30 and 35 amps. At 120v the generator would be working on 50% capacity. I was thinking it would be nice to be able to utilize a little more if possible.

Also for the 240v 50 amp. I was under the impression that when the voltage dropped the amps would stay the same. So 240v at 50 amps is 12000 watts. If I split the 240v to 120v and the amps went to 25 then I would get 3000 watts from each 120v line. That is 6000 total. It seems that we have lost some wattage.
 
  #7  
Old 11-15-15, 01:30 PM
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Goldstar, I can wait to see what a sparky says. When I add everything up I believe his equipment pulls about 17 amps from 5 or 6 items. and 17 amp is when all are on at once. I am thinking I may have explained something wrong. In the end I was thinking I could power his equipment and use the additional power from the generator to power a few other items in the home. Your original post makes me think the generator can do more than I was estimating.

Anyway how do I know someone is a sparky?
 
  #8  
Old 11-15-15, 01:39 PM
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When I add everything up I believe his equipment pulls about 17 amps from 5 or 6 items. and 17 amp is when all are on at once. I am thinking I may have explained something wrong.
And in his room how many outlets are you using? Is his room and a 15 amp breaker in your electrical panel? Im sure there are other outlets in the home on this Branch no?
 
  #9  
Old 11-15-15, 01:53 PM
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Apologies if I am not using the correct terminology. We are using 1 outlet (top plug) for his oxygen machine (5 amp) and then the rest of the equipment is on a power strip plugged into the bottom plug of the same outlet.

After rereading what I wrote and your comment I am wondering if I am looking at something wrong. We have never had a problem with the breaker blowing.

We moved into the house about 8 months ago. Never had any electrical problems. But the breaker box is not very helpful. There are a few breakers labeled but for the most part I am guessing. The circuits I believe are the outlets are either 15 or 20 amp. The home was built in 1980.
 
  #10  
Old 11-15-15, 01:56 PM
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If you want to use the 50 amp outlet IMO your best off making a cord and getting a transfer switch for the home..

Get a 50 amp inlet like this where you will plug the gen into.. Close to your panel if you can..

Reliance Controls PB50 50-Amp Power Inlet Box w/ Flip-Lid

Then a cord...

Generac 6389 - 50-Amp 25-Foot Generator Power Cord w/ Straight Blade

Then a transfer switch..

Edit.. Oh better yet they sell as a package..

Just select 10 circuits for the home.. 10 @ 120v..

Reliance Controls EGD-Q510KIT 50-Amp 120/240V 10-Circuit Power Transfer System w/ Interchangeable Breakers


I think that gen has a floating nuetral. This is important. If it does not then you need to do something else. Either unbond the gen or put in a different switch...
 
  #11  
Old 11-15-15, 01:58 PM
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Take a pic of your panel if you could
 
  #12  
Old 11-15-15, 02:16 PM
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Name:  Panel 11-15.jpg
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Here is a picture of the panel. Let me know if you had a different pic in mind.
 
  #13  
Old 11-15-15, 03:38 PM
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You need to do this in a logical manner.

First thing, do you have city water service or are you on a well with a pump?

Second thing, do you have city sewer or a septic system that requires a pump?

If you don't need a pump for either water or sewer it makes this Campbells soup easy.

Your son's needs add up to 17 amperes at 120 volts. That is just over 2000 watts. I suspect that the circuit breaker controlling the receptacle in the bedroom is rated at 20 amperes, which means a maximum of 2400 watts non-continuous or 1920 watts continuously, which is defined as more than 3 hours. Since you haven't had any problem with the circuit (that you have told us) I strongly suspect the continuous load is no more than 1900 watts and could be significantly less.

So, you have a continuous load of 2,000 watts on a 10,000 watt generator. That leaves about 6,000 watts that can be used for other purposes.

You state your heat is electric, what type of electric heat? Is it baseboards in each room with individual thermostats or is it an electric boiler, or an electric forced-air furnace or perhaps a heat pump? What form of auxiliary heat do you have?

Honestly, I think a separate "standby" circuit breaker panel is your best solution. You CAN add an automatic transfer switch IF your generator can be adapted to remote starting but that may not be necessary.

Answer the questions and we will go from there.
 
  #14  
Old 11-15-15, 04:27 PM
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Also given my math before I would only be able to power 4 15 amp circuits. I have about 24 circuits in the home. I would not be about to power the heat since it is electric. Does my logic make sense that I would only be able to power 4 circuits?
You can energize all 24 circuits using your generator (hooked up through the main panel or using a whole house transfer switch.)

The generator's power can be divided in any proportion among the 24 circuits so long as the total power drawn is not too much for the generator. With only a few small items on each circuit (lights, radio, maybe a medium draw item such as a cake mixer on a few circuits), you could actually have all 24 circuits drawing power at the same time.

Electric heaters draw lots of power so, although you can use heaters, you can't turn on very many heaters at the same time.

I was under the impression that when the voltage dropped ...
You should never draw so much power that the voltage drops noticeably. (The generator breaker should trip before such a large voltage drop happens.)

The generator can supply 33 amps at 240 volts, or two allotments of 33 amps at 120 volts. You may not draw more than 33 amps (120 volts) from one side even if you draw less than 33 amps from the other side.

Some transfer switch units allow you to (require that you) select, typically between 6 and 15, branch circuits that will be eligible to receive generator power. A 240 volt circuit counts as 2 circuits in this situation. If you put a transfer switch between the main panel and a subpanel then only the circuits in the subpanel can receive generator power.
 

Last edited by AllanJ; 11-15-15 at 04:43 PM.
  #15  
Old 11-15-15, 04:40 PM
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Furd. Thank you for replying. I have city water with a septic tank. There are pumps attached to the septic. Heat is a heat pump with built in aux heat.
 

Last edited by bob_ubak; 11-15-15 at 04:43 PM. Reason: spelling
  #16  
Old 11-15-15, 05:07 PM
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AllanJ. Thanks for the info. I had looked at a transfer switch for just a few circuits and was not too sure. I also looked at an interlock device. Sounds like a whole house transfer switch is the same thing but safer (not saying interlock is unsafe just read a little that made me uunsure). Where would I find a whole house transfer. Is it as simple as searching online for one? Seems like some electrical searches are tougher than that.
 
  #17  
Old 11-15-15, 05:31 PM
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No other heat such as a fireplace or pellet stove? If not, then I assume that you only need a generator to use for a short term power outage for your son's medical equipment, correct? That in case of a prolonged outage you would be moving to a place that still had power, correct?

If you wanted to stay at home during a prolonged outage then you would need heat, some kind of cooking facilities, refrigeration as well as communication (TV, Internet, telephone) and some form of entertainment, which could be just a lamp for reading.

Do you have just a sewage pump, to pump the raw sewage to the septic tank, an effluent pump to pump the outflow from the septic tank to the drain field or both? Do you know the size of these pumps, horsepower or volts and amps? Obviously you need to power this/these pump(s) to stay in the home during a prolonged outage.

How about your kitchen range, gas or electric?

Normally it is fairly easy to determine "emergency" generator needs as most people do not need to be able to use all the modern electrical conveniences during a relatively short term outage, say a few days at most. You, or more specifically, your son, is/are a special case. For myself I can live quite comfortably with a 3,000 watt 120 volt (only) generator for several days. In fact, I did so just a couple of months ago when a windstorm caused extensive damage to the utility's overhead wiring. I, along with many neighbors were out for about 60 continuous hours yet I was quite comfortable in my own house. Of course I have gas heat AND the outside temperature was fairly mild. I cooked with my table top convection oven and microwave, took my shower as normal (gas water heater) and was able to play on the Internet and watch TV (antenna, not cable) normally.

It MAY be possible to run your heat pump with the generator by disconnecting the auxiliary (emergency) heat strips. Having a high powered electric hot plate would allow you to make soup or many other things without using an electric range, assuming that your range is not gas-fired. Between the hot plate, microwave oven and a table-top toaster-convection oven you should have no real problems with hot meals. Refrigerator and freezers do have a momentary high starting demand on the generator but again, they shouldn't be a problem with that large of a generator.

The next question is...how do you plan on powering the engine on this generator? Gasoline is expensive and has all sorts of downsides, especially if the machine will not be run very often. I converted my generator to gaseous fuel. either propane or natural gas (I use natural gas) and this is ideal for an engine that may not run for many months but is needed on a moment's notice. Do you have natural gas available?

Oh, it is a good idea to "map out" every single usage of electricity to its circuit breaker. You should know which CB controls which fixed lighting and which receptacle. I suggest that you take a couple of hours to do this. Start by turning on every fixed light in the house and then turn off one circuit breaker and notice which light goes out. Do this with each circuit breaker, taking notes, till all the fixed lighting is accounted for. Then do the same for all the receptacles using a plug-in radio or portable lights. Also do this with the large fixed appliances.
 
  #18  
Old 11-16-15, 07:54 AM
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While this generator is capable of doing a lot more than just supplying the medical equipment, really all you need is a heavy duty 12 gauge 100 foot extension cord and a small hole through the house wall somewhere to snake it in. You could even get one with a 3-way outlet on the end to avoid also needing the power strip.

If you had two such extension cords, you could run one to the son's room to power the equipment, and run the other to the living area/kitchen to meet the basic need there. The generator has two 120V receptacles from the factory.

A full transfer switch set up will probably approach $1000 while the cord option is about $150.

A half measure would be to buy a power distribution box that will spilt out the 30A outlet on the generator into multiple 120V 20A GFCI circuits into which you can plug standard extension cords.
Example1: http://www.amazon.com/Coleman-Cable-.../dp/B003RRWWAY
Example2: http://www.amazon.com/CEP-Constructi.../dp/B000KL4I2K
 
  #19  
Old 11-16-15, 10:38 AM
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ibpooks - I like the idea of a power distribution box. Seems to make sense. Do they make these that would convert the 240v 50 amp to 120v outlets. That would let me use more power from the generator.
 
  #20  
Old 11-16-15, 10:42 AM
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Furd - Thanks for the reply. Unfortunately everything in the house is electric. This includes the stove. I would have access to propane but it would be via tanks. No NG or Propane lines to the house. You are also correct that if the power outage was longer term we would need to leave. The main use of this generator would be for my son. I was just thinking of using it for other comfort if possible. I also wanted to get away from running cords through the window. ibpooks mentioned a power distribution box. I am thinking i could easily set up a outlet outside and connect it to a single outlet inside. The connect that to a distribution box. Not sure what direction I will go but I do need to make this easier.
 
  #21  
Old 11-16-15, 11:40 AM
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Yes, they do but the price ramps up higher than it seems like it should for only a slightly larger amount of materials in the device, plus you need to buy the 50A cord.

http://www.amazon.com/Coleman-Xtreme.../dp/B000289AQK
http://www.amazon.com/Coleman-Xtreme.../dp/B000289ACE
 
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