Installing 30 amp service at home

[Keith Oliver]

Has anyone run into this problem, and solved it?  I wired in a 30 amp outlet close to my Beaver, plugged in and got...nothing.
My voltmeter says the outlet is fine, reading 119v.  The outlet is a Cincinatti RV outlet that I bought at an RV store.  I put a 30 amp breaker in the house panel just for this outlet.
I was told to check polarity, so without a polarity checker, I reversed the leads, but that made no difference.
I thought maybe the contacts were NG, but when I plug the 50 to 30 pigtail into the outlet and test at the 50 end, I get the full 119v.
Just when all this is plugged into the 50 amp hose, I get no power to the coach.  All of the individual pieces (except the new outlet) work just fine plugged into a long extension cord, on a 15 amp outlet in the carport.  This uses an adapter to go up to the 30 amp pigtail, then to the 50 end of the motor-home cord.
I am puzzled, and will leave the 15 amp hookup in place for now, till I figure this out.

[John Harris]

I had two welding plugs where our coach is parked and just converted one to a 50 amp RV hookup and everything works fine with our 99 Monterey, but I don't know about a 30 amp hook-up.

[Randy Perry]

Make sure the "hot" wire (from the circuit breaker in your electrical panel) is wired to the copper colored terminal on the 30amp outlet and the white wire should be on the silver colored terminal and the ground wire to the green colored terminal. Sounds like you may have the white and green swapped! If this is your fix, you may not have a good ground!!  

[Keith Oliver]

Red to copper, white to silver, bare to ground.  All terminals clean and shiny, yet still nothing through to the coach.  Go figure.

[Joel Ashley]

Our coach's Magnum panel accepts settings for the nature of the campground powersource;  I basically tell the inverter system whether I'm hooking to 15, 20, 30, or 50 amps at the post by changing the settings on the LCD remote inverter panel.  Conceivably this is more to protect the system (which I'm fairly ignorant about) than anything else.  You may not have such a setting capability on your rig, but even if you do, I'm not certain changing the setting to 30 amp would actually make a difference.  I went quite a while when our coach was new before I realized the settings were there, so we plugged into many different amperages then without changing settings, and no obvious harm came of it.

For some reason you 1) can get 15 amps into the coach just fine, and 2) have full voltage available from your new outlet, even at the female end of your 50 amp pigtail.  I would suspect something in the coach is balking at the configuration, but other than my comment above, I'd have to concede, Keith, I don't know what it could be.  I too have a 30 amp outlet for the coach beside our house, but have had no problems.  Perhaps Gerald or Ed, more electrically savvy than me, will proffer more valuable ideas.

-Joel

[Edward Buker]

Basically the outlet wiring is just as Randy stated. The tutorial in this link explains the wiring and has some photos.

http://www.myrv.us/electric

The breaker that feeds the outlet should be a 30 Amp single pole 120V breaker that uses one position in the panel and sees just one side (120V) of the incoming power distribution panel. There should be 10 guage Romex wire feeding the outlet. At the breaker panel the white wire is tied to the neutral buss, ground wire to the ground buss, and the black wire to the 120V breaker. If all the connections are tight and the outlet and panel are wired as discussed then there may be an issue with the Rv wiring, perhaps the main cord or the 30 to 50 amp adapter is defective. I would check the adapter first.

Later Ed

[Gil_Johnson]

Keith,

I can't follow what you've done.  You have wired a 30A circuit to provide power to your coach.  I assume on a 30A socket.  You then plug in your coach and get nothing.  But you also said your coach works fine when you use your 50A to 30A adapter cable.  How are you using this without the adapter cable?

Not specific to your problem, I would recommend running your 30A/120VAC feed to a 50A/220VAC socket so you can use your coach's 50A plug without an adapter.  When doing so, the single Hot wire (black in the US, red in some other countries) would have to be jumpered to both hot connections on the socket.  This doesn't give you any more power, but it does eliminate the need for the adapter cable.

Gil

[Joel Ashley]

Keith is getting voltage to his new outlet, Gil, as evidenced by his direct test of it.  And his 30A to 50A pigtail shows voltage at the 50A end when plugged into the new outlet.  So voltage is available to the coach's 50 amp cord.  He also has a 15/20A to 30A adapter plug, like most of us carry, so he can connect to the pigtail, and use an ordinary 15 amp extension cord to plug his coach into his carport's household outlet that has no known issues, and does give him minimum power for battery charging, lights, etc.

Sounds like Ed is on the right track, as I have had adapter plugs overheat and go belly up, and they can be a weak point, as Gil alludes to;  even though voltage tests okay on a meter, doesn't mean they can handle the amperage draw anymore, and actually become a fire and shock hazard - so check the adapter's and the pigtail's contact condition for tell-tale melted/singed rubber.  Gil's comment about black/red wires makes me mindful also that you possibly have a mixup at your panel, as Ed suggests;  black in the U.S. is likely red in Canada.  But I get the impression you are savvy re. those basic wiring concepts, and barring adapter/pigtail causes, there is only the coach system left to zero in on.

It would be nice if you had a 30A male to 15A female adapter to plug into your new outlet;  then you could plug a heater or hairdryer to ascertain if you've got at least some amperage capability there.   Most people don't have higher amp devices with the correct plugs on them for testing for full 30 amp.  (Obviously, routinely plugging 15 amp cords into 30 amp outlets via adapters is not adviseable because it takes the circuit breaker's safety factor out of the picture, especially if there are no breakers or fuses to protect things at the other end of the cord.)

You might also derive some benefit by reading an adjoining thread on this Forum, "Electrical Issues", which may provide you with a lead on any coach settings or wiring matters impacting your situation.

-Joel

[Keith Oliver]

Joel:
Thanks for your thoughts.  I don't have a 15/30 reverse adapter.  I may try building something that I can plug a hair dryer into, to check for full amperage capacity.  I think I have checked everything else that can be checked.  I am away from the coach now for a while, so I won't get back to this issue right away.  Trying to get away for a summer trip on the boat, so will check in again when I get back.

Gil:
I have been considering changing up to a 50 amp plug in the new box, but that will need to wait a while too.

Ed:
The breaker is 30 amp, bought just for this installation.  The wire is #8, as the run is fairly long.  there is one other connection before the plug, and I have checked the connections there and found them solid. Adapter was my initial suspect, but the voltmeter at the female end, reads 119v. The adapter is also in the system when I plug t the 15 amp cord, through a 30/15 adapter, and in that use it works fine.  Everything then goes through the main cord, and in the 15 works fine, also in every other 30 I have used, and every 50 I have used.  

So where does this lead?  Is there something about the power supply that the Coach automatic switching unit dislikes?  If so, why does it work fine on the 15 amp.  All 15 come from the same source as the 30.  I have even tried changing the15 from one side of the service box to the other to test the theory that the power on one side is different than the other, but that made no difference to the coach.  Stumped.

[Bill Sprague]

Keith,

Don't know if this helps, but on my rig the shore power relay (transfer switch) is powered by one of the two legs.  I forget which one.  But, if there is not power to that leg, the switch does not connect to shore power.  If indeed your 30 amp outlet is standard and hot, the 30 to 50 adapter should connect and power both legs, one of which has the transfer switch.  When the switch see the 120, it will lock on to the shore power.  Have you tried plugging in the adapter to the 30 amp and testing for voltage at the two hot holes in the 50 amp adapter?

Bill

[Edward Buker]

Kieth,

This is a bit of a mystery....

I would say that the breaker may be defective and not making good enough contact to allow the current to flow. The other possibility is that mechanically the 30 amp adapter is not mating to the 30amp outlet to supply the required current.

 Take two small lengths of heavy wire (10GA solid) and bend it on itself to make a "plug" that you will push into the 30 amp outlet. Then bend the other ends, one to each prong, temporarily around the two prongs of a 120v plug that goes to a heat gun or space heater. Once you have a good temporary set of connections made, then turn on the breaker and see if the system takes the load properly. If that works then I would suspect the 30 amp adapter cable is not mating well to the outlet contacts. There really is no difference in feeding the coach with a 15amp outlet and a 30 amp outlet. They are both single phase 120V with a hot, neutral, and ground connection....somehow one of the connections is not being made using the 30amp circuit.

Later Ed

[Joel Ashley]

Ed has a great idea, Keith, and his suspicions may be on target.  You may also reconsider buying the 30A to 15A reducer I mentioned.  I have one because on occasion that outdoor RV outlet is the quickest and handiest for temporarily plugging some tool into.  It would serve to test your outlet in this case also.  You could also flip off the breaker and remove and disassemble the box and outlet to observe the mechanical interaction with the 30A plug.

-Joel

[Gil_Johnson]

I think Bill is right.  You must not be getting both legs of 110V into the coach.  You may just be getting one leg.  Check your 30A to 50A adapter and make sure the hot lead on the 30A has continuity to BOTH 110V leads.

Gil

[Edward Buker]

Gil and Kieth,

When Kieth was able to get the coach to power up with a 15amp outlet he had to be using the 30 to 50amp adapter as well as a 15 to 30 amp adapter. That being the case he has already tested the continuity of the 30 to 50 amp adapter legs. This problem has to be related to the the 30 amp new outlet mechanical contacts to the plug or the breaker. I am assume that the wiring is correct at this stage of the game.....

 He needs to test a current load through the outlet, and if that works, then through the adapter with that plugged into the new outlet. Ultimately, he is not getting power to the coach as Gil indicated, but it would seem that the problem must lie on the new outlet side of things....good mystery on this one.

Later Ed

[Keith Oliver]

Thanks for your continuing interest.  I will get back to this issue when next I get over to Saltspring Island, where the mystery outlet resides.  That may occur late next week, as we are planning on doing a Gulf Islands cruise in our boat, starting Friday.  If you don't see me active on this site, I will be actively pulling my prawn traps or such boating pursuits.