30 amp plug into 50 amp socket

[vermilye]

Something to think about - the NEC allows a smaller wire size for the ground wire once you get over #6 wire. The reason? The ground is there to force the main breaker to trip when there is a fault to ground. Because the short circuit current is high, even a much larger breaker will trip before the wire heats up enough to cause damage. I'd never use a #16 extension cord plugged into a 50 amp circuit through adapters, but as I stated earlier in the thread, a dead short on a normal length #10 power cord will trip a 50 amp breaker before it overheats.

I have not seen a RV with a dual 30 amp power cord - the usual feeds are a 120v 30 amp through a NEMA TT30 connector or a 120/240v 50 amp through a NEMA 14-50 connector.

By the way, a couple of good reasons to use a 50 to 30 amp adapter -

1.The campground only has 50 amp connections. Unusual, but it happens.

2. The 30 amp receptacle is in bad shape. Since most RVs are 30 amp, it will be the most used, and may be worn to the point where it overheats, damaging your plug. Yes, you can ask the campground to replace the connector, but that doesn't always work.

3. When the campground wiring system is overloaded (high temperatures have everyone running 1 or more ACs) there will be times where one leg of a 120/240v supply may provide higher voltages. If you have 2 dog bones, each wired for the opposite leg, you may be able to find one provides higher voltage, letting you run your AC. The choice of legs when manufacturers build these adapters seem to be random. Take a multimeter to the store & check through the connectors to choose one of each.

Some individuals have made adapters that can be switched between legs, or if you have the $, buy one of these: Power Solutions PDF (See Page 3) or for a little more $ ebay .

[jgmcbride]

I am the original poster and all of you though have not agreed, you have given me food for thought and for that i am truly grateful.

That is what makes this furm work the way it does!!!

[DAN L]

Originally Posted by jgmcbride

I have a 2011 Winnebago Vista which is 30 amp unit. A fellow RVer once told me before I had this unit, that it is a good idea to carry an adapter so that if only a 50 amp RV site was available I can still plug in.

Tonight I purchased one. For the life of me, I can't think of any drawbacks in using it if I were to need to plug into a 50 amp source.

How about it, guys (girls)??

i use a progressive 50a portable surge protector all the time and sometimes use a 30a adapter with no problems so far.
i also have a 20a-30a adapter and 10 gauge 3 wire extension cord from home depot for use when i plug in at someone's house.

Electrical Tutorial

RVUpgradeStore - Progressive Industries Smart Surge 240Volt 50Amp Inline Model

[sparent]

So on this same subject.... I have my coach converted down from 50amp, to a 30amp, and then adapted down to a 20amp connector with about 60ft of an extension cord running into my house... hoping to do nothing more than put a charge on it over night.... and yeah well it doesn't seem to work. It doesn't trip any breakers, but it also doesn't even seem to kick the converter on.

I am wondering.. which part do you think could be the breakdown? Assuming it will work on a 20amp connection at all, would the distance of my cord or the gauge of the cord be the bigger factor? I haven't actually tested it on 20amp and seen it work at all yet...with or without an extension cord.

Thanks.

[Journey39n]

Interesting discussions. But I wonder about all those that said you shouldn't plug your 30amp cord into an adapter that will plug into a 50amp socket.

Have any of you ever plugged in, say a 10amp appliance, into a 15amp or 20amp socket in your house? Of course you have, we all do it all the time.

As long as the adapter is wired correctly, you will get the power you need at the coach. Your coach is wired to only draw 30 amps or less, hence the 30amp cord.

If you are concerned in the least about your power, why not get a good circuit/surge protector. I have too much invested in my coach not to have one.

[Dr4Film]

Originally Posted by sparent

So on this same subject.... I have my coach converted down from 50amp, to a 30amp, and then adapted down to a 20amp connector with about 60ft of an extension cord running into my house... hoping to do nothing more than put a charge on it over night.... and yeah well it doesn't seem to work. It doesn't trip any breakers, but it also doesn't even seem to kick the converter on.

I am wondering.. which part do you think could be the breakdown? Assuming it will work on a 20amp connection at all, would the distance of my cord or the gauge of the cord be the bigger factor? I haven't actually tested it on 20amp and seen it work at all yet...with or without an extension cord.

Thanks.

Depending on how your coach is set up, you need to tell your Converter/Inverter that you are hooked up to ONLY a 15 or 20 amp shore power source.

I think what is happening is that the converter is trying to draw too many amps and is shutting down.

Just a guess!

Dr4Film ----- Richard

[wb7auk]

Time out....
When one uses a 30 amp connection you are limited to 30 amps.
That is the reason units that use a 50/30 adapter have to limit what they use.
A person that uses a 30/50 adapter will have a feed of 50 amps in the power cord
until it reaches the unit then limited to 30 amps. If the cord has a problem in most
cases the 50 amp breaker will trip.
Now a 50 amp connection has two 50 amp feeds and allows you to draw a total
of 100 amps but that load is split in half so your unit is limited to 50 amps on each
half of the electrical system in your unit.
So the answer to is it ok Yes or the National Electrical Code would not allow the
adapters to be made and sold.

[John Hilley]

Originally Posted by wb7auk

Time out....
When one uses a 30 amp connection you are limited to 30 amps.
That is the reason units that use a 50/30 adapter have to limit what they use.
A person that uses a 30/50 adapter will have a feed of 50 amps in the power cord
until it reaches the unit then limited to 30 amps. If the cord has a problem in most
cases the 50 amp breaker will trip.
Now a 50 amp connection has two 50 amp feeds and allows you to draw a total
of 100 amps but that load is split in half so your unit is limited to 50 amps on each
half of the electrical system in your unit.
So the answer to is it ok Yes or the National Electrical Code would not allow the
adapters to be made and sold.

The NEC doesn't have any power as to whether or not any thing is sold. It only provides guidelines that a regulating authority can use to insure safe electrical installations. UL is the testing entity that certifies that an electrical device meets certain guide lines.

The adapters are safe from an electrical draw point of view, but there may be some mechanical problems, especially with 20 amp to 30 or 50 amp adapters at the receptacle. Sometimes the orientation of the plug, straight or right angle won't fit in weather proof housings allowing the heavy cord to slightly pull the adapter out of the receptacle causing a poor connection that may heat up and cause a fire. If every thing plugs in securely, it should be safe to use the 20 amp to 30 or 50 amp cords for powering the converter and light loads.

[wb7auk]

Ha Ha which came first the chicken or the egg.

[krautkamper]

Originally Posted by sparent

So on this same subject.... I have my coach converted down from 50amp, to a 30amp, and then adapted down to a 20amp connector with about 60ft of an extension cord running into my house... hoping to do nothing more than put a charge on it over night.... and yeah well it doesn't seem to work. It doesn't trip any breakers, but it also doesn't even seem to kick the converter on.

I am wondering.. which part do you think could be the breakdown? Assuming it will work on a 20amp connection at all, would the distance of my cord or the gauge of the cord be the bigger factor? I haven't actually tested it on 20amp and seen it work at all yet...with or without an extension cord.

Thanks.

I would guess the problem is in the adapter. When you go from the 50A plug to the 30A, it can only supply one of the 2 legs. It is not supplying the one that powers your converter. Does anything at all in the coach work? I have seen some threads on this forum where people have built a special adapter to power the other 50A leg. Maybe you can buy an adapter that does that.

[RustyJC]

The standard 50A female to 30A male dogbone adapter jumpers the L1 and L2 legs of the 50 A side together and feeds them both with L1 from the 30 amp pedestal receptacle. Therefore, IF the 50 A female to 30 A male adapter is wired and functioning correctly, there should not be a dead bus in the 50 A RV's power distribution box. If there is, the first place I'd look is the adapter - using an ohmmeter, there should be continuity between L1 on the 30 amp side to both L1 and L2 on the 50 amp side.

Rusty

[wa8yxm]

I will cover some of the high/low points.
Will an adapter that allows a 30 amp rig to plug into a 50 amp outlet work? yes
Will it work better than plugging into a 30 amp outlet? Depends on the condition of the 30 amp outlet.
Are there campsites that have ONLY a 50 amp outlet? I have not seen them, but this does not mean they do not exist, I seem to recall reading of a few of them.

Is ther any danger? Some will argue that you can short a 30 amp cord and it will not trip a 50 amp breaker.. A true short WILL trip the 50 amp breaker before damage occures.

IF you are using an extension cord, and the plug/socket is lying in water.. THEN you might have a situtation, but this will only affect the easily replaced extension cord and NOT the cord into the rig (Save for the easily replaced plug part) so I'd say it's safe.

Would I recommend a 30 amp rig carry an adapter: YES.. In fact I recommend all RVers carry a full set of adapters so as to let 'em plug into most anythign save the famous outlet that LOOKS like a 30 amp but is really 220 volts.. (And yes, you can even make an adapter for that one.. Though I do not recommend doing so)

[wb7auk]

Thank you Rusty Ditto

[wb7auk]

And thank you too John

[Dave78Chief]

Originally Posted by sparent

So on this same subject.... I have my coach converted down from 50amp, to a 30amp, and then adapted down to a 20amp connector with about 60ft of an extension cord running into my house... hoping to do nothing more than put a charge on it over night.... and yeah well it doesn't seem to work. It doesn't trip any breakers, but it also doesn't even seem to kick the converter on.

I am wondering.. which part do you think could be the breakdown? Assuming it will work on a 20amp connection at all, would the distance of my cord or the gauge of the cord be the bigger factor? I haven't actually tested it on 20amp and seen it work at all yet...with or without an extension cord.

Thanks.

Do you have a Converter/Charger or Inverter/Charger?

For reference, a 60 amp Converter/Charger (thats 60 amps DC not AC) produces less than 800 watts. It only takes at most 7 amps AC to produce that 800 watts. So, a 20 amp AC circuit is more than enough to handle the charger as long as everything else in the rig is OFF. If you have a House Battery Disconnect, it has to be ON in order for the charger to see the state of the battery.
Take a voltmeter and before you connect the 50 amp cord into the 30 to 50 amp adaptor, make sure you have 120VAC available on both L1 and L2 pins (measure L1 to neutral & L2 to neutral; should have 120VAC at both points) at the output of the adaptor. The 30 to 50 amp adptor should short L1/L2 together so it is available on each leg. If one side is missing, then there may not be any AC power being applied to the converter. You are still limited to 20 amps max with that setup. If I recall correctly, if you have a EMS system, the 15 or 20 amp shore power selection is only used to control load shedding. Only other thing I recall is that a few inverters manage charger vs inverter power distribution. Without knowing exactly what you have one can only provide possibilities rather than actual expectations (far to many varibles).

Dave

[Dr4Film]

Originally Posted by wa8yxm

Are there campsites that have ONLY a 50 amp outlet? I have not seen them, but this does not mean they do not exist, I seem to recall reading of a few of them.

In fact I recommend all RVer's carry a full set of adapters so as to let 'em plug into most anything save the famous outlet that LOOKS like a 30 amp but is really 220 volts. And yes, you can even make an adapter for that one.. Though I do not recommend doing so.

I happen to be staying at Beverly Beach Camptown RV Resort in Flagler Beach Florida where ALL sites are 50 amp. The office will loan anyone the 50-30 amp dog-bone to use if the rig is not 50 amp.

Also, I did make one of those adapters to use with a three prong 220 VAC receptacle. I added a properly sized ground wire to pick up the ground from another close location.

Not to change the topic but I recently helped a young lady with two daughters who were all here from France and they were staying at Beverly Beach Camptown for a few days. They had their Class C motor-home which was shipped from Europe and were planning to tour the US and Canada for the next 6 months. Unfortunately, their shore power plugs were completely different than what is required in the states. To solve their problem, I took a new adapter that they would normally use in Europe and cut the European plug off and wired on a three prong 20 amp plug. They also had a Stepping Transformer which you could select either 120 VAC or 240 VAC input. I had her put it on 120 VAC input for the duration of her US & Canada tour. I also had her purchase a 20-30 amp adapter so as she travels to many places, she can either plug into a 30 amp or a 20 amp receptacle for her shore power needs.

Dr4Film ----- Richard