50 to 20 Amp Adapter

Philip Rank · 01-21-2015, 10:22 AM

Just purchased a Mighty Cord RV15M50FDT adapter so I could connect my Honda eu2000 to my Silverback 29ik without going through the 50 amp cord and two adapters which work fine, (everything works in RV) but are awkward to use. Problem is, when using the RV15M50FDT, only a few 110 volt items work, such as the microwave and refrigerator on AC. Items such as ceiling fan and TVs do not work. Is there a way I can readily correct this? Thanks.

Philip

Batts-toy · 01-21-2015, 10:49 AM

Welcome to the forum Philip, first of all you are asking a lot from a little 20 amp circuit on the gen. I suggest getting another Honda eu2000 (the companion unit, and 30 amp adapter to connect them together) run both of them with 30 amp output and adapt it to your 50 amp cord this should give you more usage in the TT but you still won't be able to run everything at once (such as the second AC unit). Do a search of the threads in this forum and you can find some tables of amp loads various appliances etc. pull and be able to determine what can be ran at any given time.

Oakman · 01-21-2015, 10:52 AM

Your ceiling fan and TVs should work when you are plugged into the Honda. Check the circuit breakers and trip them to off and then back to on. Also I think (not really sure) the ceiling fan is on a GFCI circuit. Find the GFCI outlets with the reset button and push that in. If that doesn’t work then perhaps someone else will have some ideas. All of the 110v appliances in my Silverback work with my Honda 2000, just not all at one time of course.
I’m sure you already know this but the Honda 2000 only produces 13.6 amps so you are limited as to how many appliances you can run at one time.

BTW, welcome to the Forest River Forum.

Philip Rank · 01-21-2015, 11:19 AM

I am careful what electrical items I run at the same on the 13 amps generated from the eu2000. I do expect that individually, everything with the exception of AC should work. (AC might actually work, but there is not enough power to properly run it). When I disconnect the new 50 - 20 adapter and plug into 50 amp shorepower everything now works. So why not with the adapter?
Philip
Thanks for the warm welcome to the forum. We have used our 2015 Silverback 29ik for four months, love the design and problems have been few, readily corrected by our dealer, so we are pleased with our purchase. I think this forum is really informative.

fonzie · 01-21-2015, 11:29 AM

If you have a multimeter, check your 50 amps side adapter that you get 120 volts between neutral and each hot (L1 and L2), maybe only one line is hook up. That would be between W and Y.... and then W and X.

**wmtire** · 01-21-2015, 11:46 AM

Quote:

Originally Posted by Philip Rank

Just purchased a Mighty Cord RV15M50FDT adapter so I could connect my Honda eu2000 to my Silverback 29ik without going through the 50 amp cord and two adapters which work fine, (everything works in RV) but are awkward to use. Problem is, when using the RV15M50FDT, only a few 110 volt items work, such as the microwave and refrigerator on AC. Items such as ceiling fan and TVs do not work. Is there a way I can readily correct this? Thanks.

Philip

Philip. it almost sounds like one leg of your 50 amp RV is not being powered from the adapter.

In simple terms, your 50 amp RV consists of 2 legs (L1 and L2) which in reality comes from a 120/240 volt split phase power supply. Inside your RV, some electrical things will run off of the L1 side, and some things are over on the L2 side.

When you use a properly wired adapter, you are actually splitting a single feed ( L1) over to the L2 side.

You might want to see if the adapter is actually outputting this single feed to provide power to both your L1 and L2.

You could just have a bad adapter and it's not providing power to both sides.

EDIT: I was trying to find a pic like Fonzie showed. You can ignore my post as Fonzie has you covered.

MuddauberE · 01-21-2015, 12:01 PM

I agree with WMTire. a 50 AM service has two legs which I would think a typical 20AMP adapter cannot provide. It should only be designed to run one leg and a 50 AMP circuit is a two leg circuit. If it is designed for two, then it cannot possibly provide enough ample power to run all items in your trailer. A 20AMP will provide some items power but it's really not design too run everything otherwise they would have wired the trailer for a 20 AMP connection.

As an example of a more dangerous situation, I have a 30 amp trailer. It is designed for just one power leg. I have the ability to connect a 20AMP plug into it and everything runs. But first off, I am taking a chance that if I try to power something that required more than the 20AMP can provide at once, such as running the fridge and the AC at the same time, then I may damage circuitry within the appliances.
Second, If I did power something on like the fridge and the AC unit, I pop the fuse and the wire gets so hot that it's a fire hazzard.

I have installed the proper 30AMP plug in my garage to eliminate any issues.

So back to your 50AMP service, I'm surprised they make a converter like this and it's probably only "meant" to do things like charge batteries and run lights. You do not want to run high AMP pulling items and limit what you do turn on. Or install a 50AMP service in your garage and then be able to run everything.

**wmtire** · 01-21-2015, 12:54 PM

Quote:

Originally Posted by TGR

Fonzie misstated the wiring.

TGR, I don't believe continuity is the issue. As Fonzie correctly stated, he needs to check "voltage" for both of the legs...and make sure that each leg has 120 volts coming thru it. It has to be plugged into a power supply to check voltage. X and Y are your two "hot legs" with W being a shared neutral between the two. The confusion my be that you are only checking for voltage at the female end of the adapter cord.

If there is no voltage, then you might want to unplug the adapter...and change to continuity, and see if something is wrong/broke in the wiring between the male and female ends.

However, if he is powering at least one leg, then I don't think the problem is going to be continuity. It's most likely going to be an internal problem inside the adapter that splits the L1 to the L2.

He can test the unpowered adapter using continuity as you suggested, to make sure there is continuity at the X and Y female end from the male end of the plug, since they should be tied together internally in the adapter. If not, that would indicate a fault somewhere.

fonzie · 01-21-2015, 12:59 PM

Quote:

Originally Posted by TGR

Fonzie misstated the wiring.

I just checked my 50A to 15A adapter. Using fonzie's chart above, there should be continuity between the G on both ends of the pigtail, between the W on both ends, and between the unlabeled prong on the 15A plug to both the X and Y on the 50A receptacle. It is the X and Y that are at issue in your problem.

Wmtire explained the reason a missing leg or perhaps a poor connection is your likely problem.

I did not misstated the wiring.

**Flybob** · 01-21-2015, 01:08 PM

A 50A to 20A or 30A adapter is not just the reverse of a 20A to 50A adapter. They are wired differently.

TGR · 01-21-2015, 01:46 PM

Sorry for my confusion in the response to the missing power. I was thinking of checking for continuity in the adaptor wiring instead of checking for voltage from the pigtail.

The directions from fonzie were correct. I removed my posting to avoid confusing the issue further.

Ke5rbd · 01-21-2015, 03:17 PM

Most likely the plus and negative in the 110 plug on the Generator are reversed. If you have a tester you can check that. On the 15 amp receptical the wide terminal goes to the white ground. Here is a link that has them all listed. Plug and Receptacle Configurations
I have encountered this in camp grounds several times when using 30 amp to 50 amp adapter. The 30 and 20 and 15 are suppose to be wired the same way.

MuddauberE · 01-21-2015, 04:26 PM

Quote:

Originally Posted by Flybob

A 50A to 20A or 30A adapter is not just the reverse of a 20A to 50A adapter. They are wired differently.

Correct! And if you take a 2L (50amp) wire and convert it down the a 1L (20 amp) wire, there will defiantly not be enough voltage to go around. Now you have 1 hot wire trying to supply two hot wires and it just cant be done safely.

Put in a 50amp plug where you park your trailer and forget about all the science

**wmtire** · 01-21-2015, 04:46 PM

The OP is only using the adapter because he is using a portable Honda generator, as explained in the opening post.

Oakman · 01-21-2015, 05:36 PM

I don't have any electrical savvy but I'd bet a dollar to a donut the problem is with his adapter. When I power my Silverback with the Honda 2000 I use a 50 amp to 30 amp dogbone adapter and then a 30 amp to 20 amp plug adapter. The 20 amp then gets plugged into the Honda. As I stated before it will power all the 110v appliances but naturally not all at the same time.

AquaMan · 01-21-2015, 07:43 PM

I would also say the problem is in the adapter. I have a 50 to 15 adapter and use it all the time. It will run everything in my 5er, with the exception of the AC. When I say everything, I'm talking 2 fridges, lights, at least 1 tv, and stereo, at the same time. I don't use the microwaves or ACs. I have an EMS and never run over 15amps. I don't camp like this, I only use it when parked at the house. It's completely safe and doable.

Sent from my iPhone using Forest River Forums

caper · 01-21-2015, 08:00 PM

If the adapter was to supply both legs from a 20 amp outlet there would only be 10 amps per leg. The 20 amp adapter will only supply one leg of the 50 amp service.

**wmtire** · 01-21-2015, 08:12 PM

Quote:

Originally Posted by caper

If the adapter was to supply both legs from a 20 amp outlet there would only be 10 amps per leg. The 20 amp adapter will only supply one leg of the 50 amp service.

Caper, it also took me a little to get my head on this straight a few years back as I thought something similar.

However, this isn't necessarily the way it works. The 50 amp services are two legs (or hots) which are L1 and L2....along with a shared neutral and ground. (4 wires total). This is commonly called a 120/240 volt split phase service.

A 30/20/15 amp service is one leg (or hot) which is a L1....along with a neutral and ground. (3 wires total)

When using an adapter to plug a 50 amp into a single L1 service, what the adapter does is "shares" or jumps the single leg L1 over to the L2 line too. The neutral and ground are the same. The power is in reality shared, not split between the two legs inside the RV

Now both legs of the 50 amp service are being fed by just the L1. Both legs are powered, but just by L1. You will have power to everything in the RV......but instead of 50 amps per leg as normal (100 amps combined total), you now are going to be limited to either 30/20/15 total depending on what amp outlet you are plugged into with the adapter. There is a lot of difference between 100 amps total and either 30/20/15.

Hold on and I will find a great schematic that's been posted several times that shows this.

What can happen, is if the adapter is faulty or incorrectly wired internally, then the power isn't being jumped/shared from the L1 over onto the L2, thus anything electrical inside the RV wired on the L2 side is not being powered.

Philip Rank · 01-21-2015, 10:19 PM

When I posted my first thread on this forum I had no idea the participation would be so keen and extensive. Thanks to everyone who commented. Special thanks to Fonzie and wmtire for enlightening me. I have discovered L2 at the female end of adapter will not carry current and a closer inspection shows that there is no contact point to enble L2. For those of you that have a 20 to 50 amp adapter that powers your entire RV, I would appreciate knowing the name and model of your adapter. I now realize that given my generator has an output of 13.6 amps and the converter requires 12 amps to charge batteries, there is precious little power in reserve when the converter is running. I expect to use the generator on rare occasions when boondocking. Philip

**wmtire** · 01-22-2015, 01:47 AM

Quote:

Originally Posted by Philip Rank

a closer inspection shows that there is no contact point to enble L2.

Philip, I'm not quite sure I'm following you here. I am going to post a few pics showing a typical 50 amp locking receptacle, as well as a modified form of Fonzies pics using the same wiring color code as the schematic I posted to clarify.

Black= L1
Red= L2
Grey= Neutral
Green= Ground

The 50 amp may appear to only have 3 terminals, but the fourth wire (ground wire) is not typical....which may be confusing the issue. Maybe these pics will help.

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