50 amp more reliable?

[eldermike]

Originally Posted by Goodspike

Wow, that is good, although I'm not sure of the explanation at the end. But I can understand why that would be a huge issue given different circuits often share a common neutral on the way back to the breaker box. I'll pay more attention when I see open neutral in the future.

Please have it repaired for the next guy who might have 50amp service. I have been in the situation where I had to explain the wiring to the repair person at a campground. Once he understood he checked ever pedestal in the campground over the week we stayed there. He also purchased a tester that uses a load to check the neutral condition on the 50amp plugs. I left him alone and just watched a bit as he made several repairs that week. A lot of campground are built in flood prone areas. Sometimes these pedestals are underwater for a week or more. Corrosion on internal connections is most often the issue you will find and a simple tightening of a screw can save an RV.

[powercat_ras]

My surge guard lights a warning light if there is voltage difference more than 2 volts between ground and neutral, an electrical industry rule of thumb for non-medical power receptacles is that neutral to ground voltage difference should be 2 volts or less, even with full load being pulled from a receptacle. It can be higher as there is current flowing in the neutral that causes voltage drop where under normal conditions there is no current flowing in the ground so no voltage drop there. If the voltage is over 2 volts then the neutral wire may be under-sized or have some higher than normal resistance connections between the point where the voltage is being read and the main electrical service panel feeding the power, which is the closest point where neutral and ground are physically tied together. Or, if higher the neutral to ground common point may not be in the right place in the electrial system feeding the receptacle.

Personally when first I plugged my RV into my home electrical service, the ground warning lit on my TRC (now Southwire) 35530 hardwired surge guard. I discovered that there was a separate ground bar and neutral bar in the main electrical breaker box, and they were not bonded together. Once bonded, the difference between Neutral and Ground at the RV even with pulling 20 or 30 amps thru the neutral fell to less than 1 volt.

Expressing a concern with your campground management in a campground setting, or consulting a licensed electrician in a residential outlet setting - is a good idea if you are reading more than 2 volts AC between neutral and ground at any outlets inside your Travel Trailer or RV.

[Goodspike]

Originally Posted by eldermike

Please have it repaired for the next guy who might have 50amp service..

Maybe we should all start carrying 30 amp outlet plugs so that the camp repair person has parts!

[Phil G.]

Several comments in this discussion bring to mind a question:

When using a generator, there are interface connectors available to plug into the generator that you then plug the cord from your RV into. These are called "bonding plugs" ... which short ground to neutral. They are intended to trick some of the modern power monitoring systems in RVs that are designed to not pass power to the RV if they detect a ground-neutral problem in wherever you plug your RV's power cable. These power monitoring systems can make it impossible for an RV'er to use a generator for power unless a bonding plug is used.

I wonder ... should a power pedestal's neutral be shorted to ground someplace between it and the RV - using a 30A or 50A "bonding adapter" - in order to help mitigate campground pedestal power quality or mis-wiring problems?

[Goodspike]

Originally Posted by Phil G.

I wonder ... should a power pedestal's neutral be shorted to ground someplace between it and the RV - using a 30A or 50A "bonding adapter" - in order to help mitigate campground pedestal power quality or mis-wiring problems?

That may or may not be a good question, but my question to you is how would you do that? Bring a grounding rod to pound into each campsite?

[powercat_ras]

No, you don't want to tie ground and neutral together at additional places besides the main electrical panel. As I mentioned in post #82, normal load current flowing thru the return neutral wire path can create a slight voltage on the neutral side (normally less than 2 volts).

If you tie neutral and ground together at the RV, now part of the normal load current will flow thru the ground wire and part will flow thru the neutral wire. The ground voltage is no longer zero due to the voltage rise of the current flowing thru the ground wire. You could now touch something that is tied to the shore cable ground like the exposed metal of your RV and get shocked. It's a small voltage but still can be lethal in certain situations. There was an electrocution last year where a child coming from swimming was in bare feet standing on the ground and reached up to open the door of their RV and their RV had a few AC volts present on it.

The only time your RV has a direct Neutral to Ground connection is when you are powering from your internal generator, there is a Neutral to Ground Bond either inside the generator itself or in the generator side of the transfer switch box. As noted in post #84, most portable generators don't normally have neutral and ground connected internally and it's a good idea to make a bonding connection that connects neutral and ground together at the portable generator if not already there. One way to do this is to buy a grounded plug and wire a 14 gauge wire strap between the Silver (Neutral) and Green (Ground) screw inside the plug, then plug it into one of the outlets on the portable generator.

[powercat_ras]

Is grounding your RV to the earth with a ground rod a good idea? Maybe, but ...

The problem is what it takes to do it right. The elctrical code requires use of ground rod of 8 foot in length. Or another code alternative is to install a earth grounding system in a concrete pad. Whatever is used, the requirement is that the resistance from the ground wire to the earth must be less than 25 ohms. Industry best practice is to obtain 5 ohms or less. Generally, electricians just drive 2 ground rods separated a few feet apart for a residential structure and call it done.

To measure this requires a specialty ground resistance meter and training to measure it correctly.

[Goodspike]

Originally Posted by powercat_ras

Is grounding your RV to the earth with a ground rod a good idea? Maybe, but ....

I was not necessarily suggesting that as much as suggesting it would be impractical. For one thing, you might hit some park utility driving the rod into the ground. In Washington State you would need to call in a utility locate company to do it legally.

But I was just thinking more of the hassle of having an inventory of grounding rods, a sledge hammer and making a lot of noise! I can no longer edit my response above to make that move clear.

[powercat_ras]

Originally Posted by powercat_ras

... There was an electrocution last year where a child coming from swimming was in bare feet standing on the ground and reached up to open the door of their RV and their RV had a few AC volts present on it...

A common cause of large current flowing down the ground wire of the shore cable causing a voltage high enough to be dangerous on the grounded parts of an RV is a defective electric heating element in the hot water heater. Sometimes they fail in such a way that the current flows back from the electric heating element to ground rather than to the neutral wire.

The most dangerous problem is an open ground, then any current path to ground in the RV, even a very small current, causes hot skin on the RV ..

There is a inexpensive device called a non-contact voltage tester that one can use to check for voltage, here is an informative video:

How to test for an unsafe RV "Hot Skin Condition"

[Goodspike]

Originally Posted by powercat_ras

A common cause of large current flowing down the ground wire of the shore cable causing a voltage high enough to be dangerous on the grounded parts of an RV is a defective electric heating element in the hot water heater.

Another good reason to just use the propane heater function. My water heater is only 110 volt, but I leave it unplugged just so I don't accidentally turn it on and burn out the element if there's no water. I've never used the electric and don't plan to unless the gas does not light.

[eldermike]

Some multi meters have NCVD built in although they are expensive. What I do is check ac voltage between the chassis and the earth using my multi meter. I do this if I suspect an issue. Here again the progressive industries surge protectors read the ground connection. They are easy to use and a bad ground light would be a quick and easy find before you plug in. I purchased mine years ago when my wife said she was shocked by opening the door from the ground. Sure enough I had a voltage from chassis to the dirt. I do not trust pedestals until I read the lights. If you are not doing it you are benefiting from those that do because that is why they get repaired.

[CharlesMoore]

Gesh, the Phil_G asked a simple question. The simple answer is yes, it is ok to use the adapter as long as it is 3750W rated. The RV itself is fused at 30 A (I presume) and this will open the circuit not allowing more than 3750 watts into the RV. I doubt that using 50 over 30 makes a difference so I would use the 30A but you can use 50 if you want to.

[CharlesMoore]

To continue my previous thread: RV Park and Marinas are notorious for marginal outlets. I cannot tell you how many cables I have that have been ruined by faulty pedestal receptacles. SO, I almost always use an inexpensive shorter cable to go from the pedestal and then connect my very expensive RV cable to it. This is being done by me and I take very good care of my RV cable and the receptacle of the short header cable. I also use a very small amount of "conductive grease" to lightly coat the RV plug pins and then slide it into the short header receptacle. As an example look here: https://www.mcmaster.com/conductive-lubricants

[Goodspike]

Originally Posted by CharlesMoore

Gesh, the Phil_G asked a simple question. The simple answer is yes, it is ok to use the adapter as long as it is 3750W rated.

I'm sorry, but it's pretty obvious you either did not read the thread or cannot understand what is being said. It is not okay.

[Goodspike]

Originally Posted by CharlesMoore

Goodspike, you are a funny man.

No I am an informed man. I understand most electrical issues and most electrical risks. To say a dog bone adapter is okay if it's rated for 3,750 watts is at best ignorant.

Again, have you read the thread? It does not appear you have. I'm hardly the only one saying it is unsafe. The contrary argument is simply that it has been done a lot without issue. That does not make it safe.

[Phil G.]

Originally Posted by powercat_ras

You can get a 50A plug to two 30A socket adapter. One 30A socket is off 50A phase 1 and other is off 50A phase 2. You can read AC volts on each socket and plug your 30A into the socket has better power, if there's a difference. They sell for under $ 40.

I just re-read this discussion thread and noted the above.

That's the way to go (by using a voltmeter to test for which 30A line of the adapter has the least sagged voltage on it) with one important change ... each of the two 30 amp legs of the adapter should be in-line fused to trip at 30 amps.

For what it's worth, the "number of connections" remains the same when in use on a 30A RV ... as a 50A-to-30A adapter that is constructed to use only one or the other leg of 50A service on the power pedestal.

A 50A-to-30A adapter with two 30A feeds to choose between, with each line 30A fused, would then be a "poor man's way" to sometimes get around sagging 30A voltage from campground power ... as opposed to bust-the-budget use of a $$$$ line conditioner.

[Goodspike]

Originally Posted by Phil G.

as opposed to bust-the-budget use of a $$$$ line conditioner.

Do those things really work? I don't mean do they raise the voltage--I assume they somehow do. But is there a downside to that, like maybe considerably less available amperage or some such thing?

[Phil G.]

Originally Posted by Goodspike

Do those things really work? I don't mean do they raise the voltage--I assume they somehow do. But is there a downside to that, like maybe considerably less available amperage or some such thing?

I think the best ones keep voltage from sagging (much) on their output - that's why they cost the big bucks.

HOWEVER ... putting on my pre-retirement EE hat ... you can't get something for nothing. The line conditioners raise and regulate the voltage on their outputs probably by consuming more current at their inputs.

That's probably why line conditioners are banned for use at some RV parks ... as they raise amperage draw in the park's main power panel - and thus lower the voltage even more for all other campers - in order to keep voltage within specs for the RV line conditioner users.

[Goodspike]

Originally Posted by Phil G.

HOWEVER ... putting on my pre-retirement EE hat ... you can't get something for nothing. The line conditioners raise and regulate the voltage on their outputs probably by consuming more current at their inputs.

Thank you for that. I guess in a way they are effectively some sort of a variable transformer. I like your "can't get something for nothing" comment.

[youracman]

Originally Posted by Phil G.

Note in that Amazon link above -> referring to an inline 30A circuit breaker with two pigtails coming out each side with no plugs or receptacles on the ends of the pigtails - that the product description of it down below the picture talks mostly about the company that offers it being able to build custom interface cables.

I'd recommend contacting that company before you order anything: Ask them to build one for you with the 30A breaker inline with ... a short pigtail of 50A rated cable coming out one side with a RV pedestal 50A plug on it ... and a short pigtail of 30A rated cable coming out the other side with a 30A receptacle on it to accept the 30A cable plug coming from your RV's shore cable.

Order the above from them all ready to use -> and hopefully quailty-constructed by folks who know what they're doing and who are fully aware of UL Certification-type requirements.

Just posting back on my 'sperience with the company that makes the "ckt breakered pigtail" from Amazon. I got on their website and filled out the form that they said would yield a response in 2 or 3 days ............ did that almost 2 weeks ago. NADA. So I guess I am gonna have to break out the the wire strippers and phillips screwdrivers and install my own plug and receptacle. Agree, Phil; would have been nice to just buy it ready made.

Once done, I will be comfortable knowing that I don't have 30A wire from the coach's breaker panel looking back at a 50A breaker when I'm plugged into a 50A pedestal with an adapter (AKA a dog bone?) ...... actually it's my favorite way to hook up when available cuz the campsite's 50A receptacle is usually "tighter".

Best............ ed s