? for John T.

One summer, few years ago we had a power outage. One can get by for several hours without power, so I don't worry very much when the power goes off. We live out in the country.
I learned that it was going to be off for 2 to 3 days. So I got our small motor home out that has a 4000 watt Owen generator on it.

I wanted 3 things to run.

Refrigerator medium size
Water pump 1/3 hp 120 volt
Water heater LP power burner, much like an oil fired furnace, less than 2 amp.

I removed the wires from the breakers that feed the refrigerator and the water pump, and tailed them out and put them on a male cord cap. and ran a neutral from that cord cap to the neutral bar in the panel. Then it into an extension cord from the the running generator. The pump started up, I went up stairs and the refrigerator was running. Good, all was well.

The water heater has a cord on it that just plugs into a receptacle, but I needed a short extension cord to reach the cord from the generator.

When I got back to the basement with a short extension cord, the water pump had come up to pressure and had shut off, but the refrigerator was still running. I plugged the water heater in, and the generator shut down.

The pump and refrigerator would run together.
The pump and water heater would run together.
But the refrigerator and water heater would not, it was not an over load for them to run together, the water heater is a very small load. Much smaller than the water pump.

John, my question is, why would the refrigerator and water heater not run together ?

The generator was built in 2002.


Thanks,
Dusty

Darn Dusty youre makin me have to "think" and Im getting ready to leave early tomorrow in the RV for 6 weeks and my brains pretty much full up lol

We have to think n discuss this maybe we can figure it out, maybe not???????? Maybe my sparky buddy Buick man or some of the other sparkies here can help also I HOPE SO

Wonder if theres some sort of Neutral and Equipment ground issue between your panel and that Onan and the configuration in that water heater and theres a dead short goin on thats tripping out the Onans breaker or causing its shut down???????????? Far as I know theres no GFCI out of that Onan right??????? if there was that could be an issue but I dont think they are GFCI protected.....

I think in that Onan its Neutral is bonded to its frame and its frame is, of course, bonded to the RV frame. In the RV panel Equipment ground is bonded to the RV frame BUT THE NEUTRAL AND GROUND ARE NOTTTTTTTTTT BONDED THERE like at home cuz that bond is already formed at the RV pedestal outlet. On mine theres a receptacle the RV cord plugs into so when its running the RV is plugged into it the same as if plugged into an RV park.

That hot water heater 120 VAC is just small electronics for controls etc but is it a 2 or 3 wire????????????????? If its only 2 there may just be a transformer load so I dont see how there can be any Neutral/Ground problems. If its a 3 wire perhaps that may be causing a problem BUT DARNED IF I KNOW HOW OR WHY JUST YET

The fridge and water pump are likely 3 wire devices with equipment ground bonded to the frame on both those appliances. BOTH those devices are basically inductive loads for whatever thats worth lol

AS OF RIGHT NOW I CANT ANSWER YOUR QUESTION but think about what I said and let me cogitate on this while packing the RV and let me know if you have any more ideas and see what other sparkies say n maybe before the sun sets we can get this???

I will check back later

John T

You do realize what you described is back feeding on your panel nuetral to the lines outside which could electrocute a lineman?

Isolate everything from your panel only feeding from the generator. After all they have the power shut off for a reason and don't need you backfeeding through some mall transformer and causing fatalities.

Is the short cord you ran over to the water heater too small??? Maybe have a short or other issue??? Please tell me it is not one of those little lite cords. They will not carry more than a few amps.

As to him back feeding the main lines. He would only be doing that if he tied into the hot wires. HE took them out of the breaker. He is tied into the neutral bar BUT THAT IS grounded at the house. So it would not be back feeding the main line.

If he wants to be sure just flip the main breaker off. I did that for years before they came out with the switches to flip them over. I had 3-4 circuits wired into a common cord. That cord would reach out to my generator. I would just flip the main off and turn off the breakers on the circuits I was using. They where then feed through the cord supply. No current could go back through because the main and the individual breakers where shut off.

I now have a stand alone generator that is run off of propane. It is all automatic. If the main electric is off for 1 minute it starts up and switches selected circuits over to the generator. When the main electric has been back on for 10 minutes it shuts down and switches the circuits back to the main line.

I wish I had installed it years ago. I can remember waking up to no electric an having to go start a tractor and hook up the PTO generator. Half the time before you would get it all done the electric would be back on. You had to get started if it was real cold because the tractor would not start if you waited too long after the electric went off. I have to keep the well pump going because the cattle waterers don't hold much and thirsty cattle will cause problems.

I wish I had as much grace and patience as
Ol"John T . As a licensed industrial Electrican that now works
for a power distribution utility. I just want to take about 1/2 the
people who do amateur wiring and connect thier cheap dumb
*sses direct .To the aboimnations they are so proud of saving
money with. residents and workers get shocked, burned ,
injured or killed with these homebrew messes.Then some
dork keeps telling me "But it works" which for some reason is
supposed to make his jackleg connections ok. Not certain
what you are doing with some sort of pig tail and running back
to the Neutral bar but undo the mess you made and put it all
back correctly. Now get off your wallet and call a local
licensed electrical contractor. Instal a proper service entrance
transfer switch. There are low cost units that plug into the
utility meter base. As for what you "need"? I have had people
tell me they only "need" loads 1,2 and 3 and they seem proud
of making do on the absolute minimum. Well is doesn"t take
any extra to be able to flip on any light in the place when the
gen set is running.some time when the roads are closed is
when somebody falls on dark stairs and breaks bones.
I just let my co-workers read your wiring description and they
are shaking thier heads too.

Onan does not use GFCI breakers on their RV units. Need to put an amp probe on the line and see what your draw is.

Plus correct your wiring.

Onan tech since 1980.

Every week I get a safety brochure in my paycheck . As long as you are feeding current back into the neutral you risk backfeed. Although Buick seems to have grown tired of giving helpful electrical answers I know where he is coming from. I recently read about a lineman have both lost a leg and an arm to a 70000 volt accident . If you want to backfeed your neutral this is what you risk happening wether you or I fully understand the exact how and why of it all or if the electrical engineers feel like explaning it . Often when you get shocked it is by something that you don't understand . Then upon further investigation you discover where someone has taken it upon themselves to back feed something for working on their little circuits not telling anyone Hey I'm plugging a cord into this wiring to just get this to work .

Theres some chitter chatter below about utility backfeed risk and thats why proper transfer switch set ups are recommended BUTTTTTTTT for those who dont seem to be aware of it, the HOTS are transferred/switched (from utility or genset) but often NOT the Neutrals::::

With a two pole transfer switch where the two hot lines are transferred to feed the home from EITHER the Utility or the Genset THE UTILITY AND GENSETS NEUTRALS ARE BONDED TOGETHER. In that case the genset is NOT treated as a seperately derived source and its Neutral IS NOT BONDED TO ITS FRAME.

With a three pole transfer switch the Neutrals are switched and they ARE NOT BONDED TOGETHER. With that system the genset is treated as a seperately derived source and its Neutral is bonded to a grounding electrode and in certain situations the iron frame suffices.

THE NEUTRAL ALONE (from a genset) DOES NOTTTTTTTTT BACKFEED THE UTILITY, IT REQUIRES ONE OR BOTH OF THE HOTS from a genny to backfeed and energize the utility.

Out on the aerial utility at every few poles the HV Primary Neutrals are tied to mother earth,,,,,,,,,At the Transformers LV secondary the Neutrals are tied to mother earth,,,,,,,,at the home panel (weatherhead riser or meter base or panel) the Neutral is tied to mother earth. Most of that is done with bare copper wire and is often where a persion can touch it, its NOT a hazard but the hots are a hazard

Its more common for households to use only a two pole transfer switch and in that case the Genny and Utility neutrals are bonded together

Now ya see why myself and Buick man try to tell people who arent educated and experienced electrically TO HIRE A QUALIFIED COMPETENT PROFESSIONAL ELECTRICIAN as it might save you or your familys life and/or home but its your home and your life and risk so yall feel free to do as you please, no skin off my nose, Im here to try n help n maybe save a life NOT fight or argue so take care now

John T

Path of least resisitance.

Ive owned a ton of Onans and NONE of mine nor any I ever saw used GFCI I agree.

John T

For sure, if given a choice electricity prefers the path of least resistance, hey so do I lol

For 120/240 single phase three wire service and a two pole (L1 & L2) transfer switch the Utility and Genset Neutrals are bonded together if the genset is NOT a seperately derived service

If the Genset is a seperately derived service and a three pole (L1 L2 N) transfer switch is used the Neutrals are switched BUT NOT BONDED

EITHER METHOD (2 or 3 pole) AROUND HERE WAS USED AND WHEN I DESIGNED FOR DOD THEY HAD ADOPTED THE THEN LATEST NEC

About all the home types I have encountered/designed/specified just used a two pole transfer switch (Neutrals bonded) and the NEC and Local Utility company (the people who hire the line crew) all approved the installation and use AS THEY DONT WANT ANY POSSIBLE BACKFEED TO KILL A LINEMAN NOR DO I

HOWEVER DO NOTTTTTTTTTT DO AS I SAY CONSULT LOCAL AUTHORITY all I can say for sure is when I was an electrical power distribution design engineer we had to follow either the NEC or the DOD or local Utility company procedure and they usually used a two pole transfer switch (utility and genny Neutrals bonded) but sometimes a three pole (Neutrals switched NOT bonded)

Yall feel free to do as you please NOT what myslef or anyone here says but if in doubt PLEASEEEEEEEEEEEE consult your local authority or the NEC and hire a competent trained professional electrician THE LIFE OR HOME YOU SAVE MAY BE YOUR OWN OR YOUR FAMILY

God Bless all n keep safe now

John T

Here is a link to a safe, well designed, reasonably priced product that works very well.
My apologizes for being snarly but I get that way
when people try to maim or kill me or my brothers
and sisters in the trade.

http://www.generlink.com/about_generlink.cfm

Looks like it could be a good tool for homeowners with smaller gensets, I didnt find much detail about how its wired and how it operates.

I dont think we will ever get non electrical lay gents to understand the difference between Neutral (A GrounDED Conductor) and Equipment Ground (A GroundING Conductor) but hey we try dont we........

Until the device you posted comes into style, for regular home 120/240 single phase three wire service and emergency power, Id still stick with a two pole (switches both hots but NOT neutral) transfer switch (or at least the cheaper sliding lock out device),,,,,,,Float the gensets Neutral out (i.e. do NOT bond it to gennys frame, NOT a Seperately Derived Source),,,,,,,,,,,,Bond the Utility and Gensets Neutrals, and youre good to go and its NEC and every utility Ive worked with and any local authority Ive worked with legal and approved..........Of course, you can go more expense and use a three pole transfer switch (for seperately derived source configuration) and switch the Neutrals if that floats your boat, its also NEC and utility approved.

take care my friend

John T

John T I hate to to tell you but most RV GEN SET's that are 4 KW are single phase 120 only. and the neutral is attached to service ground in the unit. which is also the - on the gharge circut for the battery . there is no way to disconnect the neutral from service ground. I have a Kohler and it is that way. It also uses the - to start the unit. Starter is built in alternator .

GOOD INFO GREAT POST MAX BUTTTTTTTTT No need to "hate to tell me that" thats the way they are wired YOURE RIGHT I AGREE, heres the complete story, now pay attention lol.

1) If a genset is NOT configured as a "seperately derived source" and youre gonna use it to supply emergency power to the home via a transfer switch THE NEUTRAL IS NOTTTTT (or can be removed) bonded to the frame but is floated out and bonded to the utility's Neutral often at the transfer switch........ In that situation the equipment ground is ran out and tied to the gennys frame just as all other non current carrying metallic cases/enclosures AND IN THIS CONFIGURATION YOU USE A TWO POLE X FER SWITCH TO SWITCH THE HOTS ONLY NOTTTTTTT THE BONDED NEUTRAL

2) If a genset is configured as a "seperately derived source" the Neutral must be bonded to a proper "grounding electrode" and in certain situations the gensets iron frame suffices SO THEN THE NEUTRAL IS INDEED BONDED TO THE FRAME. HOWEVER in that use if you wanna use it as enmergency power and you use a transfer switch IT MUST BE A THREE POLE AND YOU SWITCH THE NEUTRALS.......

3) In an RV, the Genset is configured as a "seperately derived source" and as such the Neutral requires bonding to a "grounding electrode" and since its not convenient to drive a rod into earth as you drive down the road, the gensets iron frame is used SO YES THE NEUTRAL IS BONDED TO THE FRAME just as you correctly stated (no need to hate to tell me that lol).

NOTE I HAVE BEEN DESCRIBING HOW AND WHERE TO BOND THE GENSETS NEUTRAL IN STANDBY TRANSFER SWITCH OPERATIONS AND IF A 2 POLE X FER ITS FLOATED OUT AND NOTTTTTTTT BONDED TO THE FRAME BUT IN 3 POLE X FER SWITCHES IT CAN BE SOOOOOOOOO DONT GET THAT CONFUSED WITH HOW RV'S ARE SET UP THEY ARE CONFIGURED AND USED AS SEPERATELY DERIVED SYSTEMS AND THEIR NEUTRAL IS AS YOU CORRECTLY NOTED BONDED TO FRAME

4) Last time I checked (pretty sure still the case) if you use a portable genny say on a job site it like many small units has the Neutral bonded to iron frame SOOOOOOOOOOO does it also require earth grounding????????? the code says ifffffffffff all loads are cord and plug connected to on board mounted receptacles THEN THERES NO NEED TO ESTABLISH AN EARTH GROUND TO WHICH TO BOND THE NEUTRAL

Now I hope this helps, (and again YOU ARE CORRECT go to head of class lol) theres lots of confusion and misunderstanding when electrical questions are asked here and I do my best to help

BUTTTTTTTT no one should feel bad if they make a mistake and sorry, but I just cant explain in detail here in a paragraph what takes books to explain and maybe years of learning and experience SO IF IN DOUBT DONT TAKE MY WORD FOR IT (Im long retired and NEC rusty and may be wrong) CONSULT LOCAL AUTHORITY AND THE NEC AND STUDY UP ON ELECTRICAL DISTRIBUTION THEORY...

Hey I still try my best to help and keep yall safe but Im NOT perfect Im rusty on this but sincerely believe all I post to be true and dont ever knowingly post bad info that could get someone killed

So best wishes n God Bless n thank you for your CORRECT info


PS Im headed West in the RV to 6 National Parks the next 6 weesk so internet may be spotty but I will check in with yall when I can, sorry if I cant respond back or answer any of your follow up questions

John T

John, enjoy your trip.

Thanks, leavin in 30 minutes, visiting kids n grandkids in Memphis TN, Austin TX, San Diego CA then to Utah and Colorado for mountains and Natl Parks. Sorry your thread got hijacked we never did solve your problem, oh well, electrical questions bring out every Bill Bob and their brother in law, theyre all tryin to help I reckon, including me but it gets frustrating lol

John T

Never seen a three phase motorhome generator. Lots of single phase however with just one live line and a neutral. The odd one with two live lines and a neutral , single phase too off course.

I hope I've got this right, I've not seen one but I under stand there are RV's with 2 50 amp lines, 120/240 volt, but there are 2 breaker panels 120 volts only in each.
It would be my guess that there is a rule against having a 240 volt in a breaker panel in a RV.

Dusty

Dusty, about all late model larger especially Class A RV's use 120/240 volt 50 amp single phase 3 wire service and their 4 pole plug has 2 Hots,,,,,,,Neutral,,,,,Ground.

They use one leg of 120 VAC to run one rooftop AC and the other leg the other 120 VAC rooftop AC. If the RV park only has 120 volt 30 amp service like all smaller units use, they use an adapter and can run 1 AC but not both./.Im unsure of their panel configurations

John T