Did I Just Fry My Appliances?

[Roll_Tide1]

This past weekend I took my dad's 5th wheel to a buddy's farm to hang out for a couple of days. Both of our generators were at our farm a couple hours in the other direction. So, i ran down to the local big box hardware store and bought a brand new troybilt 6250wt.

I noticed while at the store that the only 220v female outlet on the genny was the 4-prong lock variety. The shore power cord that my dad owns has the 4-prong male variety, but NOT the lock type, its just 3 slim rectangle prongs, with a half-round ground prong at the top.

Connected to the shore power cord, my dad had the adapter that converts the 4-prong cord down to a 3-prong. I believe its quite normal to use these adapters at your house once you get your campers home. Still 220 though, i think, right?

Well, i said all that to say this: I called my electrician and asked how I might go about adapting the now 3 pronged cord to the 4-pronged outlet on the generator. He says, "just tie the neutral and ground coming out of the generator 4 prong lock outlet together and tie those both to the ground on the shore power cord. The other 2 leads from gennerator are just hot (x & y i think) so they go to the other 2 leads on the shore power cord.

So,i made an adapter with a 4-prong lock type male plug, and a 3-prong female outlet that the shore power cord would plug into with its adapter already on it. Diagram would read---generator-->four prong lock plug-->3 prong outlet (female)-->3 prong adapter on end of shore power cord (male)-->4 prong regular shore power cord.

Well, i did what he said. I made the neutral and ground leads coming from generator both tie into the ground to the camper shore power. Then I tied the remaining 2 leads to their counterparts on the shore power cord.

Cranked that bad boy up, walked into the camper and the 42" LED TV had smoke coming from underneath it! :S So, i ran back outside, and shut the genny down.

Walked around cussing and thinking about it for a few minutes and decided to try something different because it was 100 degrees and the wife and kid were HOT!

Went to my makeshift adapter and just dropped the neutral from the generator completely. Cranked her back up and ran inside, no smoke. BUT, by this point i was in deep. The microwave wouldn't work, neither would the living room tv, but my buddy was in the master bedroom and kicked on the extra AC unit, and it blew just fine. I got panicky again and just shut it down again. Left it.

When I finally got it home, i plugged it back in (correctly). Everything works fine except the living room tv, the microwave, and the kuerig coffee maker on the counter. I tested the outlet behind the tv with my phone charger and it charged my phone normally.

I'm gong back tomorrow with my multi-meter this time, and would like any suggestions on things to check. I'm not new to the camping scene, but I'm also not experienced with 220v AC either.

Help, please? or just opinions on what happened would be fine!

Awesome forum you guys got here!

[RustyJC]

Yes, a 30 to 50 adapter ties L1 and L2 together at the shore power cord so that the two hot busses of the 50 amp RV's power distribution center (breaker box) behave like the single hot bus of a 30 amp RV. Maximum current is limited, however, by the 30 amp shore power breaker in the pedestal, so the overloaded neutral scenario cannot occur.

The power management system on our RV defaults to 30 amp service when the voltage between L1 and L2 is 0VAC and sheds loads accordingly - for instance, the 2nd A/C compressor is blocked out on 30 amp service when the convection microwave is enabled. The power protection system, however (the EMS-PT50C, which we also have), shows the current draw from each bus in the RV's power distribution center regardless whether the supply service is 50A or 30A. With the hot busses tied together by the 30 to 50 adapter, both busses will show the same voltage.

The power management system and the power protection system are two completely different systems with different functions.

Rusty

[jaycocamprs]

RustyJC wrote:

If the two hot legs are in phase as you describe, there's a real risk of overloading the neutral conductor in your shore power cord. Neutral leg current is the sum of the hot leg currents, but because "proper" 120/240VAC split phase center tap neutral 50A service has the two hot legs 180* out of phase, one leg is mathematically assigned a minus (-) sign. Thus, in a "proper" 50A setup, if both legs were drawing 50 amps, the neutral current would be 50 + (-50) = 0 amps. If it were wired in phase as you describe, then neutral leg current would be 50 + 50 = 100 amps; the neutral conductor is sized for 50 amps, so the potential problem is obvious.

Besides, most power management systems look for 240VAC across L1 and L2 as an indicator that 50A service is available. If they see 0VAC across L1 and L2, they default to 30A service - that's what my system does. By doing so, it prevents the overloaded neutral conductor situation described above.

Rusty

But an adapter to feed a 50-amp trailer from a 30-amp plug does just that. Feeds 120v of the same phase to both legs. Meter it, 120v to ground or neutral. But 0v between the hot's

And our EMS-PT50C doesn't seem care if the hot are phased or not. Shows the same voltage on both legs.

[Sport45]

RustyJC wrote:
If the two hot legs are in phase as you describe, there's a real risk of overloading the neutral conductor in your shore power cord. Neutral leg current is the sum of the hot leg currents, but because "proper" 120/240VAC split phase center tap neutral 50A service has the two hot legs 180* out of phase, one leg is mathematically assigned a minus (-) sign. Thus, in a "proper" 50A setup, if both legs were drawing 50 amps, the neutral current would be 50 + (-50) = 0 amps. If it were wired in phase as you describe, then neutral leg current would be 50 + 50 = 100 amps; the neutral conductor is sized for 50 amps, so the potential problem is obvious.

Besides, most power management systems look for 240VAC across L1 and L2 as an indicator that 50A service is available. If they see 0VAC across L1 and L2, they default to 30A service - that's what my system does. By doing so, it prevents the overloaded neutral conductor situation described above.

Rusty

That makes sense. Thanks!

[RustyJC]

Sport45 wrote:

taken wrote:
I had a hard time following how you messed up the adapter. However, to clarify, the 50 AMP cord that RV's with 50 AMP service use as well as it's corresponding outlet is indeed 220V. 220V comes into the RV as the two hot legs are on opposite phases.

50 AMP Service Explained.

That's probably the most-used configuration, but do the two 110 feeds have to be opposite legs? Seems it would work just as well if they came off the same bus. Might work even better as an open neutral condition couldn't put 220V across anything. Of course no 220V appliance in the RV would work...

If the two hot legs are in phase as you describe, there's a real risk of overloading the neutral conductor in your shore power cord. Neutral leg current is the sum of the hot leg currents, but because "proper" 120/240VAC split phase center tap neutral 50A service has the two hot legs 180* out of phase, one leg is mathematically assigned a minus (-) sign. Thus, in a "proper" 50A setup, if both legs were drawing 50 amps, the neutral current would be 50 + (-50) = 0 amps. If it were wired in phase as you describe, then neutral leg current would be 50 + 50 = 100 amps; the neutral conductor is sized for 50 amps, so the potential problem is obvious.

Besides, most power management systems look for 240VAC across L1 and L2 as an indicator that 50A service is available. If they see 0VAC across L1 and L2, they default to 30A service - that's what my system does. By doing so, it prevents the overloaded neutral conductor situation described above.

Rusty

[Sport45]

taken wrote:
I had a hard time following how you messed up the adapter. However, to clarify, the 50 AMP cord that RV's with 50 AMP service use as well as it's corresponding outlet is indeed 220V. 220V comes into the RV as the two hot legs are on opposite phases.

50 AMP Service Explained.

That's probably the most-used configuration, but do the two 110 feeds have to be opposite legs? Seems it would work just as well if they came off the same bus. Might work even better as an open neutral condition couldn't put 220V across anything. Of course no 220V appliance in the RV would work...

[Memphisdoug]

The problem is that 50 amp to 30 amp adapter you used. Any 30 amp plug going to your camper can only have 120 volts input to it - 3 wires, a ground, a neutral and a power. If you didn't have that 50 amp to 30 amp adapter on the trailer then you would have been fine with the 4 wires coming from your generator - a ground, a neutral and 2 power wires. If you want to use that generator with your trailer get rid of the adapter

[Roll_Tide1]

taken wrote:
I had a hard time following how you messed up the adapter. However, to clarify, the 50 AMP cord that RV's with 50 AMP service use as well as it's corresponding outlet is indeed 220V. 220V comes into the RV as the two hot legs are on opposite phases. Just like in your home, they then feed opposite phases in your breaker box. Since all your breakers only tie into one or the other, they only get 110V. However, 220V absolutely does come into your RV.

Anyways, sorry about your mix up and glad it only got a couple of appliances as opposed to something bigger...

Oh, and here is a great site explaining RV 50 AMP 110/220V service...

***Link Removed***

So, basically I tied the neutral and ground together coming put of the 220 on the genny. Then run those to the ground wire on the shore power cord of the rv. Then hooked the two 110 legs to their respective spots on the shore cord as well. Walked in, tv smoking. Then I just completely dropped that neutral that I had tied to the ground from the generator. Cut it off the ground wire and put a wire nut on it. Walked in, no smoke but appliances acting funny.

Cut it off. Moved camper to 50amp receptacle way away from where everyone else was camping 😕

[taken]

I had a hard time following how you messed up the adapter. However, to clarify, the 50 AMP cord that RV's with 50 AMP service use as well as it's corresponding outlet is indeed 220V. 220V comes into the RV as the two hot legs are on opposite phases. Just like in your home, they then feed opposite phases in your breaker box. Since all your breakers only tie into one or the other, they only get 110V. However, 220V absolutely does come into your RV.

Anyways, sorry about your mix up and glad it only got a couple of appliances as opposed to something bigger...

Oh, and here is a great site explaining RV 50 AMP 110/220V service...

50 AMP Service Explained.

[Roll_Tide1]

2oldman wrote:
How are your ears after listening to that generator?

Lol, just fine. It ain't got s@$! On the champion 9000 we usually run.

[Dtank]

MNRon wrote:


What tommy said!!!

Some of responses don't know any more than the OP, other than they know enough not to make this mistake.

What Tommy said????????????..:R

"Oh, the misinformation & confusion!"

What *helpful* advice or information did "tommy48" offer?..:S

Either to/for the OP - or to correct the "inadequate" responses?..:h

BTW - "MNRon" - with exception of your opening statement, you posted meaningful info - rather than a senseless "jab" at/to the other posters and/or the OP.

.



.

[2oldman]

How are your ears after listening to that generator?

[RustyJC]

byrdr1 wrote:

RustyJC wrote:
The repair bill for our daughter and son-in-law's 5th wheel was $7500+ due to a dropped neutral in the RV's power cord that applied 240VAC to all of the 120VAC loads. They had power protection, but it plugged into the pedestal. Since the fault was downstream of the power protection, it was undetected. They now have a hard-wired PI system that monitors the power just as it goes into the 5th wheel's breaker box.

In your case, the horse is already out of the barn, but HERE is a 1-page explanation of RV 50 amp service.

Rusty

Nice page, you got one for the 30amp circuits that would be a good sticky on anyone's page.
Those basic I & II electronic/electricity courses at the local community college while trying to get an industrial manager degree have sure paid off for me through the years.
To the original poster sorry for your problems a TV and microwave are easy to replace, glad nothing else was messed up bad.
thanks,
randy

Randy,

HERE is the corresponding page for 30 amp RV service.

Rusty

[byrdr1]

RustyJC wrote:
The repair bill for our daughter and son-in-law's 5th wheel was $7500+ due to a dropped neutral in the RV's power cord that applied 240VAC to all of the 120VAC loads. They had power protection, but it plugged into the pedestal. Since the fault was downstream of the power protection, it was undetected. They now have a hard-wired PI system that monitors the power just as it goes into the 5th wheel's breaker box.

In your case, the horse is already out of the barn, but HERE is a 1-page explanation of RV 50 amp service.

Rusty

Nice page, you got one for the 30amp circuits that would be a good sticky on anyone's page.
Those basic I & II electronic/electricity courses at the local community college while trying to get an industrial manager degree have sure paid off for me through the years.
To the original poster sorry for your problems a TV and microwave are easy to replace, glad nothing else was messed up bad.
thanks,
randy

[steiny93]

Roll_Tide,
Don't beat yourself up to much; we've had hired electricians try and do the same thing on 3 different occasions (2 new construction scenarios and an existing structure add)

Many assume the 50amps are 220v for an rv; happens a lot more then one thinks.

I'd strongly recommend this as a great time to get some power protection on the rig. They are cheap insurance for any future situations.