30 amp question

[skiphoyt]

My brother has the below outlet in his barn that we would like to plug into while visiting. Is this something that would work?

[Robere]

Have a qualified electrician inspect the circuit and utilize a high quality surge protector to protect the electronics in your Airstream.

[blkmagikca]

There is an adapter that you can use - from 30-amp twist lock to 30-amp RV. Especially useful if you have to plug into a 3KW contractor type generator. Caution: not all twist locks are the same. Make sure you get one that is compatible with the receptacle on the barn (take the photo with you when you go to source it).

[A W Warn]

If that breaker protects that receptacle, NO, it is not a direct plugin. That is a 240v double pole breaker.
Since there are only 3 blades on the plug, it is not wired appropriately for connecting the trailer. Either the ground or neutral is missing, since 4 wires are require for a 240v circuit.

Does your camper have a 30 amp 120v or 50 amp 240v service?

ps:
The orange romex cable indicates it is 10 ga wire, which is sized appropriately for 30 amp. However, its flat shape indicates 3 wires, not round 4 wires. It could be easily converted to a properly wired 120v circuit, by changing the breaker to a 30 amp single pole and installing a RV outlet (I can't see the number on the outlet to know if it is the correct one, but it looks like an old clothes dryer plug, the type that is no longer used).

[rmkrum]

Not without changes. That is a 220 volt outlet probably for a welder. Has no neutral connection, just two hots and a ground. Not safe for a 30 amp Airstream connection under any circumstances.

Mr. Warn is also correct. No way to directly adapt that socket to RV use. Run a new circuit according to code for RV-30 or RV-50. Don’t chance blowing up all your stuff in the trailer.

[ITSNO60]

It's a 240 volt 3 wire clothes dryer outlet and it looks like it was used to back feed the house with a generator, illegally I might add. It could easily be made into a 30 amp 120 volt TT outlet with that copper Romex that is feeding it by using a hot, neutral and a grounding conductor. If the Romex is round with 4 conductors you will use only 1 hot and remove/cap the other hot. If it is flat with only 3 conductors you will move the white off the breaker and install it to the neutral bus. In the pic it looks round.

edit: Wow I just noticed AW Warn nailed it first! Only thing I'll say is the two pole breaker can still be used, just connect only one wire to it.

Incidentally the new 4 wire Romex of all gauges is being made flat. It's a very recent change.

[brick1]

An RV 50 amp service is 120 volt in a typical application. It consists of two phases, a neutral and a ground. You actually have 100 amps in total. Phase to neutral gives you nominal 120 volts. Phase to Phase gives you nominal 240 volts.
The plug for n the picture is not configured for an RV.
Orange romex is 10 ga.
brick

[tjdonahoe]

Originally Posted by skiphoyt

My brother has the below outlet in his barn that we would like to plug into while visiting. Is this something that would work?Attachment 324754

Attachment 324755

No...No...that is 220... you need 110.....get help and change it to 110...

[A W Warn]

Originally Posted by ITSNO60

It's a 240 volt 3 wire clothes dryer outlet and it looks like it was used to back feed the house with a generator, illegally I might add. << snip>>

Good catch!
I did not notice the "GEN" labeled beside the breaker.
If the owner is back feeding from a generator, not only is it illegal to do it this way, it is a crime that is punishable by prison time and large fines.
It is dangerous to the person connecting the generator and the people in the house, because of the way it is improperly done.
and
Utility workers get killed because of this, when they try to restore power.

[skiphoyt]

WOW! Being new to the forum and taking delivery on Saturday of our first, a Interstate 19, am blown away with the knowledge and help! The outlet in question was most likely used by the previous owner to illegally back feed power to the house. My brother has a dedicated whole house generator installed. My thought was this was most likely a 30 amp 110 setup since it was used to feed the home circuits. This is way above my electrical knowledge so won’t even go there. My wife calls me ‘Sparky’ even when I change a light bulb. Thanks to all for saving my new AS and possibly my life!!

[68 Overlander]

You would have zapped your converter and then it a crap shoot as to whether it got your microwave, TV, AC and Fridge. Always gets the converter but random on the others. Get the call several times every day often from embarrassed electricians. Good that you asked.

[A W Warn]

Originally Posted by skiphoyt

WOW! Being new to the forum and taking delivery on Saturday of our first, a Interstate 19, am blown away with the knowledge and help! The outlet in question was most likely used by the previous owner to illegally back feed power to the house. My brother has a dedicated whole house generator installed. My thought was this was most likely a 30 amp 110 setup since it was used to feed the home circuits. This is way above my electrical knowledge so won’t even go there. My wife calls me ‘Sparky’ even when I change a light bulb. Thanks to all for saving my new AS and possibly my life!!

What is shown in the photos can be redone correctly to connect your rig, for not much money.
<$10 for a new single pole 30 amp GE breaker.
~$10 for a new 120v 30 amp rv outlet that fits that existing box and cover (assuming it is inside the barn out of the weather)
Less than 1/2 hour to do the work (assuming the breaker box in the photo is wired and fed from the main panel correctly).

[Alex AVI]

Originally Posted by skiphoyt

WOW! Being new to the forum and taking delivery on Saturday of our first, a Interstate 19, am blown away with the knowledge and help! The outlet in question was most likely used by the previous owner to illegally back feed power to the house. My brother has a dedicated whole house generator installed. My thought was this was most likely a 30 amp 110 setup since it was used to feed the home circuits. This is way above my electrical knowledge so won’t even go there. My wife calls me ‘Sparky’ even when I change a light bulb. Thanks to all for saving my new AS and possibly my life!!

SKIPHOYT - Sorry for being late to this party. But those who got to you right away saved you & rig, but that's assuming you found a way to insert your round Ground prong into the blade outlet slots. Still, one can never underestimate the resourcefulness of people to bypass such obvious 'STOP NOW' warning signs. I don't think you would've been able to get a commercially available adapter. But someone out there could've DIY an adapter that would've blown up your rig.

Regarding your barn outlet - if it was inside the barn, it was probably used as a dryer outlet. Not many would run generators inside the barn (flammability & toxic fumes). Pre-mid 1990's all homes only needed 3-prong dryer outlets. Around 1996, NEC required 4-prong outlets (2 hot, 1 neutral, 1 Gnd). If said outlet is outside the barn, then you are probably right that it was used to backfeed a generator (improperly at best, illegally at worst based on local code at time it was installed).

Many have suggested this is easy to fix. I agree completely. But since you have disclosed your "Sparky" wife pet name, then I would not get into the how to. Your local electrician ought to be able to do the conversion within whatever the local minimum STREP (Standard Repair) charge is (some areas 1 hr, other big metro area is 2 hrs). Either way, this is a <1hr. job.

Good catch to ask first.

[skiphoyt]

Originally Posted by blkmagikca

There is an adapter that you can use - from 30-amp twist lock to 30-amp RV. Especially useful if you have to plug into a 3KW contractor type generator. Caution: not all twist locks are the same. Make sure you get one that is compatible with the receptacle on the barn (take the photo with you when you go to source it).

After reading all the suggestions and warnings I will have an electrician check this out making sure he understands this is for 110 use not 220. If in fact this outlet was used ‘illegally’ to back feed the house in the past would not blkmagikca suggestion be workable?

[skiphoyt]

Newer built homes have 2 110 lines coming in to the breaker box. This back feed outlet would thus be 220 and destroy my new rig. ‘Sparky’ rests his case!

[Alex AVI]

Originally Posted by skiphoyt

After reading all the suggestions and warnings I will have an electrician check this out making sure he understands this is for 110 use not 220. If in fact this outlet was used ‘illegally’ to back feed the house in the past would not blkmagikca suggestion be workable?

Originally Posted by skiphoyt

Newer built homes have 2 110 lines coming in to the breaker box. This back feed outlet would thus be 220 and destroy my new rig. ‘Sparky’ rests his case!

SKIPHOYT - No, the suggestion by BLKMAGIKCA would not work because your current barn outlet has 2 Hots & 1 Neutral. It has NO Ground. In order for a plug-in adapter to work, it would need to have at least 1 Hot, 1 Neutral, & 1 Ground that is needed by the NEMA TT-30 (RV 30A). Your barn outlet is a NEMA 10-30 outlet (older) that has been superseded by NEMA 14-30 (newer homes). NEMA 14-30 has 2 Hots, 1 Neutral, 1 Ground. With this, it is possible to easily create an adapter since you have 3 of the wires you need. The 4th wire (Hot) will just be capped/unused.

Single phase, 3-wire system (Ground wire is not counted) known as an Edison system, split-phase or center-tapped neutral, is the most common residential service in North America. The service transformer to your brother's house has secondary windings which has the Neutral in the middle and Line 1 (Hot) on 1 side of it and Line 2 (Hot) on the opposite side. Line 1 to Neutral -and/or- Line 2 to Neutral are used to power 120 volt lighting and plug loads. Line 1 to Line 2 is used to power 240 volt single phase loads such as a dryer, water heater, electric range, or air conditioner. So your brother's house, whether running 120 or 240 are still using the same 3 wires (+Gnd). So you've got everything needed to have a proper rv hookup. It's only a matter of having your electrician wire the correct outlet properly.

Hope this helps further. It is a confusing subject, to say the least.

[jdalrymple]

I didn't realize there was so much cross training between the legal, code enforcement, and electrical wiring trades.




Regards,


JD

[rmkrum]

There are MANY more things that can bite you on electrical wiring besides the voltage...National Electrical Code, local laws, and inspectors are just three of them...

Had a long argument with an inspector one time over if it was legal to put a 15-amp breaker on 12 gauge wiring runs in a house. Finally convinced him it was to prevent excessive voltage drops to my computer...and pointed out to him that the single outlet device on that run was only rated for a 15 amp load.

Reality was the contractor I was working with at the time, had bought a truckload of very good quality 12-gauge wire at a knockdown price that was cheaper than buying the more usual 14 gauge wire for 15 amp circuits. The minute a building inspector runs into something unfamiliar, they will declare it "wrong" because they really don't know any better.

And yup, the cross-training is rather extensive. The Overkill Engineering Department also has to play lawyer to get stuff done most days...last time DW and I built a house, we hired a lawyer to help get it done the way we wanted it.

[Alex AVI]

Originally Posted by jdalrymple

I didn't realize there was so much cross training between the legal, code enforcement, and electrical wiring trades.
Regards,
JD

JDALRYMPLE - Yes. In some localities, they can even be one & the same. Example - if I was in Chicago's McCormick Place to install an HP Mainframe computer for the annual Consumer Electronics Show, the union boss would politely tell me I can not legally "connect" my devices together and into the outlets until his electricians are there to electrically wire them in & enforce local codes . . . . this directive is non-negotiable until they see/realize that the mainframe inter-connect cables are nothing like anything they'd ever seen in their 30 yrs. in IBEW Local 134. So they sign-off on my installation and give me the ok to go ahead with wiring it together.

I no longer live in Chicago. I moved to Las Vegas. The Consumers Electronics Show is no longer held in Chicago. They are now held in Las Vegas . . . . hmmm.

[Pahaska]

Interesting. In years past, I would take IBM magnetic tape systems to New York City for the expo. Same thing. We could not plug anything into the mains. We had to wait for a union electrician who had never seen our equipment. They mostly stood there while we plugged it in.