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Using Coach Generator to Power House During Hurricane


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Posted

After having had two back-to-back hurricanes affecting my area of Florida, I was thinking about how I could use my 10 KW coach generator to power some of the house.

After the most recent hurricane, Nicole, we were without power for almost two days. I used a 100-foot extension cord reel that had four outlets on the side of the reel and plugged it into the 120 VAC outlet in the service bay. I ran the cord up to the second floor where our living area is located. I then used the four plugs on the side of the reel to power the fridge, one lamp, my AT&T Mobley device and my laptop. 

I know that whatever I decide to construct, the very first thing I must do is to turn off the 200-amp main circuit breakers to completely disconnect the house power panel from the incoming power line eliminating any back feeding to the power grid.

I have thought about two different methods to utilize the coaches 10 KW generator. 

One is to make up two long 12-gauge Romex cables that would come together in 50-amp Camco male plug. One cable would be plugged into the 120 VAC outlet in the service bay and the second would be plugged into the 120 VAC outlet on the passenger side of the coach which are on opposite power phases and circuit breakers in the power panel of the coach. The 50-amp male plug would then go into the 50-amp RV outlet I use to power the coach while parked. Once everything is plugged in then power up the generator. I would have about 1800 watts of power on each leg or a total of 3600 watts of power to use in the house. That would be enough to keep the fridge going, power some lights, TV, microwave, chargers, etc. I would not be able to run the AC, hot water heater, stove or dryer, basically anything that requires 240 VAC cannot be used. 

The second idea was to remove the generator wire from the transfer switch and wire it into a manual transfer switch that would funnel power to a 50-amp receptacle with the switch in one direction or funnel power to the onboard Surge Guard Transfer Switch to power the coach with the switch in the “normal” position. Then using a 50-amp power extension cord, plug one end into the special 50-amp receptacle and the other would be plugged into my 50-amp RV outlet on the wall. I would then have plenty of power available to power the house but keeping in mind that I would not be able to run ALL of the 240 VAC devices at the same time. I would only be able to use one at a time such as the central AC when needed, hot water heater when needed, stove or dryer when needed. 

What are your thoughts on each method? Obviously, the second method would require more work than the first. Not much work needed to put together a special cable for the first method. 

Thanks for your thoughts and comments.

Posted

Be mindful of the safety risks of having exposed “hot” conductors. One of my concerns would be if someone else comes along and doesn’t understand how you’ve set it up and tries to operate it.

Consider installing a transfer switch near your home breaker panel.  Something like this:

rliance50atransfer.thumb.jpg.38d07b8075a1b3285b0af2b05129134e.jpg

The generator feed side of the switch would connect to a male 50A receptacle like this one:

Miady 50 Amp Generator Power Inlet Box, NEMA 3R Power Inlet Box, SS2-50P, 125/250 Volt, For Generators Up to 12,500 Watts, Pre-drilling Knockouts, Weatherproof, ETL Listed

At the coach, my preference would be installing a 40 amp, 2 pole breaker off the generator wired to a new 50 amp RV receptacle.


 

 

 

Posted

Jim,

Thanks for your feedback! That 50-amp male receptable is exactly what I had intended to use at the coach end if I decide to go with method #2. The generator already has a circuit breaker on it so don't need another one.

Regarding the Generac Transfer Switch, too much trouble and expense when it only takes a few seconds to flip the main 200-amp breaker off at the main panel. My neighbor had a Generac Generator and transfer Switch installed onto his house a few years ago after they moved in. I hear the generator running about once a week as it gets exercised a certain amount of time to make sure it will be ready to go when needed.

Posted
29 minutes ago, Dr4Film said:

That 50-amp male receptable is exactly what I had intended to use at the coach end if I decide to go with method #2.

You meant female receptacle, like those at an rv pedestal, right?

Posted

For over 10 years, I've used the 50 amp shore service to backfeed the house from the coach 10kw generator.  I made a special cable that I would wire into the coach transfer switch.  The exhaust was vented out the window of the garage.  I used this setup on at least 2 long term power outages lasting 5-14 days. 

I'll admit it took about ten minutes each time I wanted to backfeed the house and with the main house breaker shut off, I wouldn't know when power came back on.  Unless power was going to be off for many hours, I wouldn't bother to backfeed the house.

Two years ago I had a 22kw natural gas whole house generator installed.  Completely turn key and large enough to handle the two AC units we have for our home.  The transfer switch is automatic and the generator directly feeds the main home load center.

I have UPS units on our internet and TVs.  So when power goes off, the lights go out for a minute before the generator kicks in but with the UPS units, the streaming TV never shuts off.

  • Like 1
Posted (edited)

Richard, I have a different approach.  Suggest your PM @Frank McElroy.  I THINK he has done this.  I have wired several homes for emergency power generator.  Our old buddy, “Mickey?” whom you probably remember ran a company and had great hands on as well as being licensed to do such.  So, this is a blend of thoughts…..and I am NOT a licensed electrician, but I was responsible for all OSHA electrical safety training and have a pretty good grasp, theoretical and practical, on the NEC.  Here goes.

First…..you MUST find the Ground Rod for your main service,  use a split lug connector and install a #10 connection.  This would be, if I did it, a piece of stranded copper, insulated of course, wire.  You want to then find a GROUND stud to the Motor Home.  I would probably just drill a hole in the front chassis near the Genny and clean the paint off a use a SS bolt and nut and put on a Wing Nut.  Whenever you use the MH Genny, you ALWAYS GROUND IT OUT.  So that is step ONE of the hookup.

Next.  YES, you are CORRECt, you MUST disconnect the 200 amp breaker.  There are kits made up for various brands or panels.  They have a sliding lock at the top. When you turn off the panel breaker, then you can turn ON the Generator FEED.  OPPS. That ain’t gonna work as you have to power the MH…so, you MUST…..follow this procedure.

Technically you have 41.X Amps of power from the Generator as that is the rated 240 VAC capacity of the 10KW system.  So YES….the 50 Amp backfeddd breaker will supply power to the house.  Herein comes the RUB.  

WHERE do you want to LIVE?  In the MH or in the HOUSE.  You can NOT do BOTH.  The safest and also most cost effective way to do the MH SUPPLIES POWER to the House is the following.

Purchase a Camco 50 A male and female plug & receptacle.  Cut remove the incoming Genny power lead from the MH ATS.  Hook it up to the FEMALE Camco  receptacle.  Mount that NEAR the MH ATS.  Install a new short lead into the GENNY contacts on the ATS and put the male plug on it.  Now you have your MANUAL ATS for emergency power.

You in effect, have FOUR 20 amp circuits or some combination to use.  You actually have 10,000 watts on each leg.  In that you will be supplying 41 Amps per leg or 41 amps on each lIne 1 and Line 2 side.  That is a HECK of a lot of power.  I use an 8KW (240] Genny this way.  I also have a well and pump.  That is almost the equivalent of another hot water heater.  I just only use ONE at a time.  I MANUALLY turn off the Hot Water and keep it off so I can use my pump.  I kill the pump for a while and build up a full supply of not water.  You should be able to exist quite comfortably….

BUT, you are probably doing what 90% of the population does…..you feed the house without a TRANSFER SWITCH…. and that is dangerous....unless you absolutely KNOW the risks.  I have gone into this a bit further in a subsequent post....and edited this one....

The WAY you get power from the RV plug for the Genny Output to the House, via your RV Plug going into the Main panel can be LETHAL....if you connect them in the WRONG sequence.  The LAST connection must always be the PLUG INTO THE GENERATOR in the MH....More on that and the concerns in the followup post....
 

 

 

Edited by Tom Cherry
Edited to highlight the ISSUES with Backfeeding a Home from a separate and NON ATS system
Posted (edited)
1 hour ago, Tom Cherry said:

 . . . the above only “violates” one rule…..which 90% of the population does…..you feed the house without a TRANSFER SWITCH….

Don’t doubt 90% follow this practice. Recognize that, as described, this poses a serious safety risk consequence and most likely violates local law. Granted the risk probability is low and accidents are an alignment of “swiss cheese” events allowing the accident to occur.  One barrier removed from a real bad day.

Edited by Jim Pratten
Guest Ray Davis
Posted

Richard,  I'm sure you know as much about these things as I do but I'll chime in anyway.

First I don't like any hot male receptacles or plugs even if they do sell them.  An extension you can plug in reversed is then a dead mans wire.

Trusting youself or anyone to remember to flip the mains is a also recipe for disaster. You could kill some one miles away.

You probably remember the threads on IRV2 about the subject but here is a link to one that might help. 

https://www.irv2.com/forums/f59/calling-all-electricians-450152.html

Here is a link to a cheap breaker interlock                                                                                                            https://www.homedepot.com/s/load%20center%20interlock?NCNI-5&irgwc=1&cm_mmc=afl-ir-10078-456723-irv2.com&clickid=QTnxC3X0VxyIRbRx-t1KvV3dUkA0vHyFLwaRwo0

Here is a manual transfer switch.                                                                                                                                                https://www.homedepot.com/p/Reliance-Controls-50-Amp-10-Circuit-Manual-Transfer-Switch-A510C/206503336?irgwc=1&cm_mmc=afl-ir-10078-456723-irv2.com&clickid=QTnxC3X0VxyIRbRx-t1KvV3dUkA0vFxRLwaRwo0

I haven't used the above devices but I have run an extension cord or 2 to power ref, lights, tv and internet several times

Posted

You guys beat me to an EDIT.....which I will do....to my original post....but want it spelled out here.  I, in haste, got my Males and Females mixed up.  OK....after you get up off the floor and compose yourself for that "TIDBIT", let me continue.

My ORIGINAL post would have had to have a Male to MALE adapter.  NOT GOOD....and I regretted doing that for a lady and was going to revise it and she decided to UPGRADE to a whole house.  The HOT MALE TO MALE DEPENDS on the knowledge....which I agree you have....but it is a bad practice.  I also have been texting Frank McElroy and got the details of his old system....SO here goes.....

FIRST...as Richard indicated....you MUST do two things and be cognizant that if you do not do them, it could be a catastrophe as well as letha.

The main or incoming house panel has to be turned off from the grid.....that is imperative....not from OUR END, but for the protection of the Emergency power crews.  THEY DEPEND on NO VOLTAGE COMING Back.  There are regs, which vary from locale to locale that actually prevent, without the proper ATS to disconnect the main panel,.

NOW....the next is the sequence of events.....as you will be using a MALE TO MALE adapter cord from the MH to your 50 amp NORMAL supply.  This is where it gets spooky.  I KNOW Richard understands this....but for the record, this is the ONLY way that it should be done....  IF you understand the shock (Lethal) hazard of having a HOT or LIVE RV four prong plug....then there is also a risk.  To mitigate this....here is the option.  Use a special MARINE male and female plug and receptacle.  You NEED a shielded MALE  connector.  NOW, that takes some research.... You need a locking connector and finding a shielded one with FOUR pins is TOUGH....but not impossible.

Hubbell CS8165C Locking Plug, 50 amp, 480V, 3 Pole and 4 Wire

The Hubbell above is  three (HOT current carrying) plug and the external metal shroud or cover is the GROUND.  NOW, by code....but it ain't in MY thinking, GOOD, one could depend on the GROUND from the MH to the Driven Ground of the POU Meter Base which has the Driven ground.  The above makes it a bit "safer" in my thinking and you also have a REDUNDANT ground.

That's the bottom line....however you want to configure your MH Generator to put out power is up to you.  I made one suggestion in the previous post....there are at least another 3 or 4 methods....and I don't want to go there again as what I might say, generically, one (and I trust Richard's background), so posting anything other than that is risky....

Posted

Using the coach generator to power your home has a whole bunch of safety concerns for both you and the power company working to repair the outage.  It must be done with full knowledge of how to safely do it and the use of the proper safety devices and the procedures for safely making and breaking the electrical connections without the lines energized.  If you don't understand how to shut off power to the cable connecting the generator to the house while making and breaking the connection, then from a safety perspective alone, you should not use your generator to power your home. 

  • Like 1
Posted
8 hours ago, Jim Pratten said:

You meant female receptacle, like those at an rv pedestal, right?

Nope, my intention is to use this male connection at the coach whereby I plug an extension cord with a 50-amp male end into my 50-amp RV shore power receptacle then plug the female end of the extension into the box at the coach once I lift the cover up and connect the cable. Once the cable is connected, I will switch the manual transfer switch from the normal coach position to the house position. Then go to my garage and double check to make sure the 200-amp main house panel has been disconnected and finally go to the coach and start the generator.

Fairly simple and entirely safe in my opinion. Might not be for anyone who is electrically challenged. So, for those people they may be better off installing a Generac Home Generator system instead of attempting to use their coach generator. Or just stick to running an extension cord from one duplex outlet in the coach to the house to keep the fridge running.

Posted
11 hours ago, Dr4Film said:

Thanks for your thoughts and comments.

Richard - This is what I installed at my house for my two 3400 KW portable inverters.  See pics below.  You could obviously do this for the MH generator.  

Pics 1 & 2 are a Reliance 50A generator input locking outlet (CS6375). 

Pic 3 - Mechanical interlock on house breaker panel.  Will not allow you to be hooked into the grid while running the generator, nor have the Reliance outlet hot while on the grid.

Pic 4 - 25' cord with one end for panel input outlet (CS6364) and 50A male connector on other that would plug into your MH generator outlet.

Lots of youtube videos on how to do this for the house panel.  Total cost for materials was about $200.  I hope this gives you some ideas of what would work best for you.

 

Generator Input Pic 1.jpg

Generator Input Pic 2.jpg

Generator Panel Interlock.jpg

Generator Power Cord.jpg

  • Thanks 1
Posted

Thanks, Bill, for the information. I have changed my mind as to how I plan to accomplish this task after having a phone call from one of the members here that had done it previously with great success.

Thanks everyone for posting their thoughts and ideas.

Posted

When I was in my 20’s I worked for FPL for 3 years as a lineman. Whenever we would go out on storm damage we were always aware of back feed from generators. The scary thing is those transformers work both directions. FPL’s primary voltage in most neighborhoods is 7600 volts and is stepped down to 120/240 so if someone turns on a generator and doesn’t have there house main off you just put 7600 volts into the power lines. We never relied on people doing the right thing so one thing that was drilled into us was work between the grounds. We would ground both ends of the area we where working on so nothing would become energized. After seeing a lot of crazy things one thing I took away from working there was a lot of respect for electricity and to never take short cuts and always put safety first.

  • Thanks 1
Posted

This topic comes up on IRV2 quite a bit with a wide range of comments on how to accomplish this.   Working in industry that relied on high voltage power distribution and equipment I also have a high level of respect for power so I'm glad people are providing different ways to do it. 

My brother lives in N Wisconsin and they get power outages in the middle of winter often.  They initially used a generator with extension cords for lighting and fridge but that doesn't help with water pump, water heater, and furnace.   He is not that knowledgeable on electrical and Wisconsin has pretty strict regs.  So when he decided to do a whole house type back up power supply he had an electrician come in install a subpanel dedicated to the circuits they wanted to control with the generator with a simple manual safety switch.  The parts themself are not that expensive, labor to have some one do this can be pricey depending on your house service panel location and accessibility.  He sent me the info on the safety switch, there are many versions depending on your setup but this is what he used. Siemens ECSBPK01 Generator Standby Power Mechanical Interlock

This requires a separate subpanel with power being fed by either the main service panel or the generator.  The circuits you want to control are wired into the subpanel.  Normal operation would be to have power supplied by the main service panel.  If power goes out he simply starts the generator and flips the switch and all the circuits that are wired into the subpanel are energized sigh no power back fed to the main service panel.  

So with all this information I set up my power distribution in the house to allow for this to be easily added.  Already have a subpanel in place with some circuits wired to it and others can be easily moved.  The subpanel already has the power going to my garage so using my generator would be fairly easy using a method that Richard and others have described.  I even have a pad set up outside in case I want to add a backup generator there and access to propane to power the generator.  

So there are safe inexpensive options for people to do this depending on their aversion to risk.  If I pursue this I will go with the manual safety switch since in the long run my wife may have to implement using a backup generator by herself and knowing her ability to retain any information when it comes to these types of systems I don't want to take any chances.  

 

Posted
On 11/28/2022 at 9:12 AM, jacwjames said:

This topic comes up on IRV2 quite a bit with a wide range of comments on how to accomplish this.   Working in industry that relied on high voltage power distribution and equipment I also have a high level of respect for power so I'm glad people are providing different ways to do it. 

My brother lives in N Wisconsin and they get power outages in the middle of winter often.  They initially used a generator with extension cords for lighting and fridge but that doesn't help with water pump, water heater, and furnace.   He is not that knowledgeable on electrical and Wisconsin has pretty strict regs.  So when he decided to do a whole house type back up power supply he had an electrician come in install a subpanel dedicated to the circuits they wanted to control with the generator with a simple manual safety switch.  The parts themself are not that expensive, labor to have some one do this can be pricey depending on your house service panel location and accessibility.  He sent me the info on the safety switch, there are many versions depending on your setup but this is what he used. https://www.amazon.com/Siemens-  ECSBPK01-Generator-Mechanical-Interlock/dp/B004Q01XSS

This requires a separate subpanel with power being fed by either the main service panel or the generator.  The circuits you want to control are wired into the subpanel.  Normal operation would be to have power supplied by the main service panel.  If power goes out he simply starts the generator and flips the switch and all the circuits that are wired into the subpanel are energized sigh no power back fed to the main service panel.  

So with all this information I set up my power distribution in the house to allow for this to be easily added.  Already have a subpanel in place with some circuits wired to it and others can be easily moved.  The subpanel already has the power going to my garage so using my generator would be fairly easy using a method that Richard and others have described.  I even have a pad set up outside in case I want to add a backup generator there and access to propane to power the generator.  

So there are safe inexpensive options for people to do this depending on their aversion to risk.  If I pursue this I will go with the manual safety switch since in the long run my wife may have to implement using a backup generator by herself and knowing her ability to retain any information when it comes to these types of systems I don't want to take any chances.  

 

Good Advice...from GeorgiaMike and Jim.   I am familiar with the Interlocking Back Feed breaker (240) Safety Device.  There are a number of them, that are NEC approved, on the market.

They have been proven to work well.  I had one installed for a friend who is a "non technical" retired teacher.  She used it about 3 times per winter during snow and ice events. However, in all clarity and due diligence, I GOOFED.  I then used a 50 Amp RV receptacle and made her up a 4 Prong 30 Amp Locking (the one you insert into the Generator) and on the other end, a 4 prong MALE End.  THAT WAS MY MISTAKE....and I was going to correct it but she opted, after several years of use, to put in a whole house system. The issue, as many have pointed out....if you plug into the generator and have LIVE POWER on the cord and THEN plug into the 50 A RV receptacle, you have a LIVE OR HOT four prong MALE plug.  The solution, once I noodled it out was SIMPLE.  Either TAPE or RESTRAIN (as in a clamp) the 50 Amp "Shore" Cord in place.  OR,  remove the RV Receptacle and HARD wire in the cord to the generator.  This is TOTALLY different from using the SHORE feed as a Backfeed....as many of us have done....with our own knowledge and safety protocols.

For those that are AGHAST.....the Interlocking NEC approved Backfeed device is attached to the COVER of the MAIN PANEL for the dwelling.  The device has a bar or tab that PREVENTS the 50 (or 30) A breaker from being ON.  However, when you TURN OFF (the main breaker) the device or tab moves out of the way and you can BACKFEED through the panel. Google or put this in the Amazon Search "Backfeed Lockout Device"

Generator Interlock Kit Compatible with Square D QO or Homeline 150 or 200 amp panels. 

Generator Interlock Kit Compatible with Square D QO or Homeline 150 or 200 amp panels. 1 3/8 inches Spacing between main and generator breaker, Professional and Interlock Kit (SD200A)

It just so happened that she lives in Richmond VA and there is a manufacturer there that makes these and they came out and checked her box.  SO, I had the electrician install a locally made one.  THEY ARE NEC approved. 

NOW....the Dilemma as Richard asked the question.  This solution, hypothetically, and meeting the requirement to LOCK OUT THE PANEL, WILL REQUIRE TWO SEPARATE 50 AMP Breakers.  The BACKFEED BREAKER is usually in the TOP RIGHT corner position.  When the main panel is ON....BINGO.....the Backfeed Breaker is OFF and LOCKED OUT.  So, you can NOT plug in and get shore power.  In order to comply with NEC, as Jim has pointed out and eliminate the LETHAL issues of a OPEN pronged MALE 240 VAC plug, you would have to have TWO 50 Amp Breakers....and TWO separate Receptacles.  One for normal SHORE use and the other for BACKFEED.  You can NOT SAFELY DO SUCH with a single one.  The post I made suggested a special SHIELDED male plug....but that is not TOTALLY foolproof as you COULD inadvertently put a finger inside and get a lethal shock.

From the site's perspective, we do not advocate any UNSAFE ELECTRICAL CONNECTIONS....and providing step by step instructions or such is risky as one NEVER KNOWS the level of electrical knowledge.  This thread is a discussion....and it also has several WARNINGS....DO NOT DO THIS AT HOME.  That is like telling someone NOT TO JAYWALK.  

BUT, Jim and others point out the issues.  SO BE AWARE that a DOUBLE ENDED MALE PLUG is a lethal shock WAITING TO HAPPEN.  

The OTHER DOWNSIDE, to the NEC approved device is that is depends on HUMAN INTERVENTION to properly turn OFF all the non essential high amperage breakers.  In my case, my wife and I wrote out instructions on WHICH breakers (stove for instance) were to be turned OFF....when the Device (unlocking the back feed breaker) was used.  We also specific instructions, written....as to WHICH circuits could be used and which could not and which were EITHER/OR and also provided a shut off for the Hot Water Heater...which was to be TURNED OFF when power was down.  THEN, which breakers to turn off so that the water could be heated for bathing.

That WORKED....but I always regretted not going back up and restraining the 4 Pin RV Plug to the receptacle.

Jim points out the need for a separate EMERGENCY panel.  Those of us that have put in a Generac or others fully understand HOW this is done and the installation of the ATS and such.  The costs of "revising" a home for a standby emergency generator can be unbelievable....especially if you have dual load panels.  My house has TWO 200 amp panels.  Code and permitting and such would require extensive electrical work....I am CAPABLE...but not so inclined.  I did it twice before and it was a really large project.  I will muddle along with my standby, but I, and I ALONE, make the connections and I have instructions and labels and a sequence of steps.

Keep that in mind....So far this post is generic and there are safety warnings.... But any further detailed  "HOW TO's" will need to be monitored as there is a LETHAL SHOCK RISK in what Richard wanted to do.  BUT, he has, based on many of us that know him, the skill set and knowledge, to use it do it in as safe a manner as he can,,,,knowing the potential for the shock hazard.

Thanks for understanding....

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