Community Forums

soonerdave · 03-16-2009, 05:14 PM

Has anyone used one of the Y adapters that plugs in to a 20 amp and 30 amp receptacle and then provides a 50 amp plug? I will be going to a campground this summer that only has 30 amp service which will not let me run both AC's, if I really could get 50 amps it would be great. I saw these at Camping World but didn't want to spend the money if they don't really provide 50 amps. Any advice would be appreciated! Thanks!

John-D · 03-16-2009, 08:30 PM

Yes. and basically... They do not work.. Now, that said they used to work but now they don't work. and here is why

Electric code requires the 15/20 amp be a GFCI these units will present as a ground fault 100% of the time to the GFCI and thus.. CLICK and you loose that leg

Now That said, I know of at least one park which is all 30 amp, not a 50 in sight, and in the hottest part of the year if they hit 50% occupancy the manager would pass out in shock (25 percent perhaps but 50, no way) so he lets folks with those boxes plug into two 30 amp outlets. that works,, but it's dangerous

50 amp service is what I call "Split phase" (means one phase center tapped) if you stand at the center it looks like two power lines 180 degrees out of phase

So if you are drawing 30 amps on L-1 and 30 on L-2 then Neutral is hauling a great grand ZERO amps.

But if you use the cheate box and both sites you plug into are L-1 (Or L-2 it don't matter) then the neutral is hauling SIXTY amps
'
It's a 50 amp line

Should be able to handle the extra 20 percent but I would not wish to bet a hundred thousand dollars on it. (The rounded price of my rig)

However If I ever park in that park in August you can bet the farm I'll do it (With some testing)

Here is a better idea http://www.psrv.net This is a device (I understand they have upgraded their instructions to cover 50 amp rigs) that lets you seperate one Air conditioner (The bed room on my rig) and plug it in independent of the rest of the house Works great

soonerdave · 03-16-2009, 10:10 PM

John-D, Thank you very much for the information!!! I sincerely appreciate the information and the time spent educating me. I will just use the 30 amp and kick im my generator when necessary, that's what they are for. Again, Thank you!!!

John-D · 03-17-2009, 02:24 PM

Well follow the link I gave you http://www.psrv.net and either order one (Too expensive in my opinion) or build one yourself (I skipped the breaker and decided to trust the park where I park)

That is what I did

The parts list for the home brew version were

One standard electrical junction box

one 12ga extension cord with LOCKING outlet from Sears

One "Utility box" from RV store (I could have avoided that if I'd gotten a longer E-Cord) I cut the box into the wall, cut the cord in half. Labeled the outlet half with a Marks-a-lot as TO BREAKER and the plug half as "TO A/C" Ran the plug half into the junction box removed the power line from the master breaker box for the rear A/C and ran it into the junction box, joined them properly and closed that box with a proper cover. ran the outlet half of the Extension cord to the breaker box and hooked it up

Plug the two halves of the cord into each other and it's like I never did anything

Unplug and I either have 120vac Generator power on the service side or...

The rear A/C is 100% independent of the house system, no issues with the GFCI to date

RustyJC · 03-17-2009, 03:11 PM

Even if you are in an old park without the GFCI, the 30/20 adapter will not provide true 50 amp service. True 50 amp service has 2 hot legs, 1 neutral and 1 ground with each hot leg having a capacity of 50 amps for a total ampacity of 100 amps (50 amps per leg x 2 legs). The 30/20 adapter will have a total ampacity of only 50 amps (30 amps for L1 + 20 amps for L2).

Rusty

GaryKD · 03-17-2009, 05:45 PM

Hi soonerdave,
I have the box from CW. It works as advertised and I would make the same purchase again. The previous posts mention all about 50 AMP service really being 100 AMPS. While this is true, to suit your purpose, the CW box should work just fine. It has for me. If you plug each plug into a separate 30 AMP circuit, you will have 30 amps on each hot leg. For my coach, this is what my generator would provide and this power works all the appliances quite nicely.

itdave · 03-17-2009, 06:27 PM

There is another issue if the coach has a load management system two 30 amps may not allow all items to run. My Intellitec System looks between L-1 and L-2 to see if there is 242 volts if so it assumes that I have 50 amp service so it will not load shed. If you use two 30 amp service the Intelitec will not see 242 volts between L-1 and L-2 and will assume you have a 30 amp services that is being split between L-1 and L-2. So even though you have 60 amps available it will load shed like only 30 amps is available and start turning things off when the load gets close to 30 amps.

With all of the issues around the Y-Box and possible problems with Load Management systems I think the idea of allowing the rear AC to be feed from a separate source sounds like a good way to go.

RVDude · 03-17-2009, 06:38 PM

itdave - can't you just disable your load system? The Intellitec load system on my Newmar allows me to disable it or chose 20/30/50 amp settings.

itdave · 03-17-2009, 07:01 PM

Yours must be different than mine. I just checked the manual and can't find anything about disabling the EMS. It is disabled automatically when the power source is the generator otherwise I don't have any switches to turn it off. There is a button for selecting between 30 or 20 amp if it does not sense 50 amp for the shore service. Please let me know how you disable yours because there are times I would like to turn mine off.

I was thinking about John-D's solution and I think it could be made simpler by installing a Double Pole Double Throw switch. You could connect the rear AC to the center terminals and then connect the output of the Rear AC circuit breaker to one set of terminals and an extension cord to the other terminals. Then depending on the position of the switch the rear AC could be feed from the source available in the coach or from an extension cord plugged into a second source.

RVDude · 03-17-2009, 07:38 PM

Bummer. I'll have to double check the vendor, I am thinking it is Intellitec but not positive. It just has a remote control feature with enable/disable and 20/30/50.

You might give Intellitec a call and see if they have a remote access port on the EMS controller so that you can add a remote controller to your EMS. Seems there must be a simple way to disable the EMS on demand. They might be able to offer a suggestion.

RV Wizard · 03-18-2009, 03:01 AM

The EMS is disabled by supplying 12 volt from the generator switch/light circuit. Any 12 volts applied to the control board at this pin location will tell the EMS that the generator is running weather it is or not. A simple toggle switch applying 12 volts parallel to the generator run light will disable the EMS.

itdave · 03-18-2009, 10:54 AM

Mike,
What a simple solution thanks. Now I need to open the panel and yours and John-D solutions.

Ed S · 03-18-2009, 07:01 PM

John-D

You said: Here is a better idea http://www.psrv.net This is a device (I understand they have upgraded their instructions to cover 50 amp rigs) that lets you seperate one Air conditioner (The bed room on my rig) and plug it in independent of the rest of the house Works great

It appears you have installed one of these on your motorhome, Is this a permanent seperation of one a/c? By that I mean, If 50 amp is available to plug in you still have to plug in the 2nd cord for the 2nd a/c? or if no power available and you were to run gen then what?

I am sorry I just do not understand this very well and appreciate your help. We park at may fair grounds (for dog shows) and most of the time 50 amp is very limited but we must run both a/c to keep dogs cool. This could be a very good purchase for us depending on you response.

THANK YOU VERY MUCH
Ed

John-D · 03-18-2009, 09:01 PM

Thank you for asking.. The PSRV device consists of both outlet and inlet

Here is a pair of very simple line drawings that represent the original system and the modified system

Circuit breaker in master breaker box-------------------Rear Air Conditioner

That was the original

Here is the new one

Circuit breaker (As above)---------- Outlet/Plug--------Rear air conditioner

Now, it's not quite that simple (there is a junction box in the line) but electrically all that is is a.. Well, straight through connection so it does not appear in the line drawing

To use the device I first unplug the air conditioner from the outlet it is normally plugged into, then I grab my 12ga cord from Sears and plug into that The 12ga cord goes to the park 20 amp outlet (See note on why sears or K-Mart)

IF I'm running off generator or off 50 amp service,, Just plug the plug into the outlet (On the PSRV you plug the outlet into the inlet) and the system is restord to factory normal

To air up a service (Driver's side) tire.. Unplug air conditioner and plug in air compressor (or other tool for that matter)

NOTE: Sears and K-mart (K-mart owns Sears) sell a 12 ga outdoor grade cord with a special outlet, it has a button you push when you plug in or unplug, this outlet tends to "lock on" to the plug you plug into it, gives a better (I think) connection and does not pull off as easily.. This is why I got my cords from there.

Lowes, Home Depot and many other stores sell 12ga cords without this locking feature, they should work well too.

since the plug and outlet I used were outdoor rated I put mine in a utility box I installed for that purpose.. The PSRV unit is designed to go in a basement storage compartment.. The main electrical storage one is a good choice