30 to 50amp

Lost · 04-28-2013, 03:31 AM

The campground we go to has some 50amp sites but most are 30amp sites. The 30amp boxs have a 30 amp plug and 2 regular plugs (not sure of their amps). Can you hook up some type of plug that will go into the 30amp and also the reg plug to get you close to 50amps or is that a big mistake? I have two A/C's but will not use them at the same time. Last summer on hot days in our old tt the voltage coming out of the wall was only around 97 volts. A/C keep turning off and on so I shut it off so it wouldn't burn up. Just looking for a fix untill they upgrade there service.

rnkburg · 04-28-2013, 03:46 AM

They make a box that has two plugs, one for the 30 amp plug and one for the 110 20 amp plug. Then you plug your 50 amp cord into it. Giving your trailer 50 Amps. I think the box is around 75.00 at the camping stores

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Bob Landry · 04-28-2013, 03:55 AM

Quote:

Originally Posted by rnkburg

They make a box that has two plugs, one for the 30 amp plug and one for the 110 20 amp plug. Then you plug your 50 amp cord into it. Giving your trailer 50 Amps. I think the box is around 75.00 at the camping stores

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You can not add voltage sources as thy are not guaranteed to be in phase. I'd like to see a picture or a link to that box.

dbrinklow · 04-28-2013, 04:53 AM

Here is a link to one on Lawrence RV

http://www.lawrencerv.com/products.asp?cat=17

SAD · 04-28-2013, 05:00 AM

Quote:

Originally Posted by Bob Landry

You can not add voltage sources as thy are not guaranteed to be in phase. I'd like to see a picture or a link to that box.

Here is the cheater box:

http://www.rvpartscenter.com/Product...DID=65&CID=589

With adaptors, you can combine 2x 20, 2x30, or 1x20 + 1x30

They work GREAT

with the following caveats:

1) as noted the two circuits you're bonding need to be on opposite phase
2) they will NOT work if one of the circuits has a GFCI breaker - which one is certainly in use at nearly every single campground post for the 20 amp / household type outlet

So..... There are very limited campgrounds they will actually work on if you expect to combine a 20 amp.... I have used mine in campgrounds that the 20 is not GFCI...

I have also used it where the campground had 2x30 - where the 30 amps are never on a GFCI circuit.

FURTHER CAVEAT... determining if the two (new-to-you, unfamiliar) circuits you expect to bond are on opposite phase is something you will need an ammeter for... If you don't have one, or are not sure how to use one for this particular purpose, this is probably not the accessory for you.

warsw · 04-28-2013, 05:25 AM

Quote:

Originally Posted by SAD

Here is the cheater box:

http://www.rvpartscenter.com/Product...DID=65&CID=589

FURTHER CAVEAT... determining if the two (new-to-you, unfamiliar) circuits you expect to bond are on opposite phase is something you will need an ammeter for... If you don't have one, or are not sure how to use one for this particular purpose, this is probably not the accessory for you.

They only need to be opposite phases if your rig requires 220, otherwise it makes no difference.

SAD · 04-28-2013, 07:48 AM

Quote:

Originally Posted by warsw

They only need to be opposite phases if your rig requires 220, otherwise it makes no difference.

Not 100% true....

Consider the following...

If they are NOT on opposite phases, you could overload the neutral in your camper shore power cord (or the adaptor box cables).

The neutral is additive if they are on the same phase... And if plugged in to a correct 125/250 50 amp, the neutral is differential only.

Lost · 04-28-2013, 08:04 AM

Thanks for all the info

I think i'll just wait untill they change over to 50amp at my camp site beside's when they do switch over I have to buy two 25' 50amp cords and the cheapest I've found is around $175 each (ouch)

DJ85 · 04-28-2013, 08:15 AM

Lost

thats a great log on name for this conversation because thats exactly what it did to me.

warsw · 04-28-2013, 10:24 AM

Quote:

Originally Posted by SAD

Not 100% true....

Consider the following...

If they are NOT on opposite phases, you could overload the neutral in your camper shore power cord (or the adaptor box cables).

The neutral is additive if they are on the same phase... And if plugged in to a correct 125/250 50 amp, the neutral is differential only.

Yep...Now that I think it over you are correct. Perfect example of getting my mouth ahead of my brain.

geo · 04-28-2013, 07:09 PM

One unmentioned aspect of this thread:

Inside the campground electrical connection box, the incoming power line is attached to a "small circuit breaker box" arrangement. In a 50 amp box, there are two hot leads, a neutral, and a ground attached to this mini-breaker box. In 50 amp, each hot lead has its own breaker, but one of the hot leads is bussed over to a 30 amp breaker and on to a 15 amp breaker for the duplex socket. And, more importantly, the input power of the box is rated for 50 amps from the distribution box of the park.

But in a 30 amp box, there is only one "hot bus" that the incoming hot lead is attached. That bus is connected to both the 30 amp breaker and the 15 amp breaker. And more importantly, the incoming power for the box is most likely rated at 30 amps, not 50 amps, from the campground distribution! So, by using an "octopus adapter" and attempting to emulate a 50 amp service, one will most likely attempt to pull more amperage than the hook-up box and incoming electrical line is rated! This could possibly have dire consequences on the campground's electrical system!

I'll leave that part to your imagination.

Ron

PND · 08-09-2013, 11:16 AM

Since this is an older post, not sure if "Lost, rnkburg, Bob Landry ,SAD, warsw, or DJ85 will see this, but here goes.

First you have to understand how the "power" in a pedestal is wired. They are a "split-phase" circuit. A pedestal that has one 30 amp recep. and one 20 amp recp. is wired such that the one 30 amp recp. is wired to one of the "hot" legs and the 20 amp recp. is wired to the other "hot" leg. Can't say I have ever seen a pedestal with two 30 amp recp., but it would be wired the same. This is done in an attemp to "balance" the loading of the "split-phase" circuit. Never perfect, but is close enough to keep the "neutral" current to an acceptable level. It seems consistant on this forum that everybody says "out of phase", which is incorrect. Noticed I stated they are a "split-phase" circuit. A single phase can not be "out of phase" with itself, BUT it has a positive AND negative half that are 180 degrees opposite with each other - hense the appearance of being "out of phase".

Remember, both the 30 and 20 amp are only one 120 volt circuit, and a 50 amp is "two" 120 volt circuits -of opposing polarity -just like in your house.

Based on the pictures that are posted, it appears to have two 30 amp plugs connected to a 50 amp recp.. I assume, based on what I see in the picture, to plug into a 20 amp recp. one would use a 20 to 30 amp plug adapter on one of the 30 amp plugs. So, the net result if you have a 30 and a 20 amp recp., and plug in this "device", you are feeding your 50 amp system with two 120 volt circuits that give you 30 amp capacity on one 120 volt circuit and 20 amp capacity on the other. If you have two 20 amp recp. then you only get 20 amps per 120 volt circuit. And as "SAD" pointed out, the net current on the "neutral" will be the difference of the two "hot" legs.

Also remember that the "neutral" in your RV and your power cord are of the same size, capable of carrying the full current, ie 50 amps for a 50 amp system.

This does look like a handy device to add a little extra AC capacity to a 50 amp system when there is not a 50 amp recp. at the pedestal.

PND
45 years in electrical
Utility wireman/relay electrican

SAD · 08-09-2013, 01:56 PM

mrwave!!

SlowPoke · 08-11-2013, 05:11 PM

These are great, when the campground is wired correctly, a nightmare when not. Considering every campground is different, aged or not, and most electrical in campgrounds are somewhat unreliable when in heavy use....I just steer clear of adapters like the one for-mentioned . I have considered getting a 50A plug and cord set to replace my 30A feeder cable. But I think a good voltage booster will be my first priority. Last trip out, my AC was cutting in/out, when I checked voltage, it was at 94V ...Day one was about 118v, but with the added people over the next 2 days into the campground, voltage dropped with all the AC's running...

Always remember, Voltage in reversely proportionate to Amperage...the lower the volts, the higher the amps will register, and that's not good for the system.

But again, this adapter is good, in CERTAIN situations, but unless you know how the system you're plugging into is wired, it's a stab in the dark as to how it will work for ya, and always a 50/50 chance you're gonna burn something up ya don't wanna have to fix.

Some campgrounds I know of will throw ya out for using hose as well....or for even plugging in to the 20A if you are already plugged into the 30A....Not all campgrounds, but SOME will throw ya out!

cabinfever · 08-11-2013, 05:30 PM

I would think if you are using a cheater box then a smart surge guard, like the ones from Surge Guard..http://www.pplmotorhomes.com/parts/r...r-portable.htm., would be a good way to protect the coach's electrical system.

Lost · 08-12-2013, 05:20 AM

Since I first posted this, I did purchase a adapter. I quickly found out that this is not a true 50amp service. The pros using this adapter is that I do get about 5 volts more (and when before using this, on a busy weekend my voltage was around 89 volts) so the 5 volts help. The cons are as you said the box in the trailer are split in 2 so one side is getting 20amp and the other side 30 amps. When using the adapter if I turned on the fireplace heater and the TV It would blow the 20 amp breaker at the pedestal. So bottom line now is that I only use it if I have very low volatge and I need to run the A/C. I could rewire the trailer box to adjust for this but I'm not going to mess with it.

PND · 08-12-2013, 09:01 AM

It seems that over in the east (I am in the NW) you have to deal with some really bad electrical systems.

Unfortunately, existing systems don't have to keep up with the newer electrical codes. To date, I haven't seen that low of voltage in our area. Are these low voltage parks private, state, or federal.

PND

Lost · 08-13-2013, 03:20 AM

Quote:

Originally Posted by PND

It seems that over in the east (I am in the NW) you have to deal with some really bad electrical systems.

Unfortunately, existing systems don't have to keep up with the newer electrical codes. To date, I haven't seen that low of voltage in our area. Are these low voltage parks private, state, or federal.

PND

I have heard the voltage problem is quite common here in Michigan. One issue that I have with the park we stay in (Old Orchard) is owned by Consumers Power which is one of the largest power companys here in Michigan.

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