2015 Thor Miramar electrical question

fred93 · 07-30-2017, 03:12 PM

My step son was planning to drive his Thor motor home up from Florida to NC to visit with us. Before he made the trip up he called and asked if I had a 50 amp 4 prong outlet that he could connect to the motor home. I told him that I had a 220v 50 amp outlet that I used for my welder, but it was only a three prong. He said he would get an adapter. He bought one from Amazon---https://www.amazon.com/Parkworld-691906-Welder-14-50R-bridged/dp/B01KV0Q278/ref=sr_1_2?ie=UTF8&qid=1501427034&sr=8-2&keywords=50+amp+welder+to+rv+power+adapter

I said that should work okay!?#@^%

Well, NOT!!!! When he got here and we plugged into to my outlet (using the adapter) I got a spark and then NOTHING.

Checking into the problem I guess we fried a few things!?@$!#

Question that I have at this point is: WHY DID THIS HAPPEN????

Also, I spoke with a Thor tech and he said that the refrigerator (which is a residential model) works off of the inverter so that you don't need to have the generator running while driving down the road.

If that is correct, we may have fried the inverter!&^%#@

How can I test the inverter????

**16ACE27** · 07-30-2017, 03:54 PM

Did you read the review for this item?

"WARNING! DO NOT BUY THIS IF YOU HAVE A STANDARD 50AMP RV PANEL IN YOUR RV!!! The two hots being bridged brings a full 240v into your RV and will damage beyhond repair any and all electronics including your microwave, stereo system(s), Converter/Charger and anything else that is expecting 110v.

The proper way to connect a 50Amp RV supply to a 50Amp Welder outlet is to have a dog-bone that bridges the GROUND and the NEUTRAL wires, NOT THE TWO HOT LEADS.

I speak from very expensive experience. Turning on the breaker immediately destroyed my Charger/Converter, killed my microwave/convection oven, burned out the 110v heater element in my hot water system and blew every 110v lamp that was turned on.

The total amount of damage is well beyond $1500."

Pretty much explains what happened in your case.

Miramar Owner · 07-30-2017, 05:24 PM

Yeah, I don't think there is anything in an RV that uses 220. The 50 amp is all 110.

Sorry for your problems with this...it can be heart breaking to experience.

fred93 · 07-30-2017, 05:51 PM

Quote:

Originally Posted by Tfryman

Did you read the review for this item?

"WARNING! DO NOT BUY THIS IF YOU HAVE A STANDARD 50AMP RV PANEL IN YOUR RV!!! The two hots being bridged brings a full 240v into your RV and will damage beyhond repair any and all electronics including your microwave, stereo system(s), Converter/Charger and anything else that is expecting 110v.

The proper way to connect a 50Amp RV supply to a 50Amp Welder outlet is to have a dog-bone that bridges the GROUND and the NEUTRAL wires, NOT THE TWO HOT LEADS.

I speak from very expensive experience. Turning on the breaker immediately destroyed my Charger/Converter, killed my microwave/convection oven, burned out the 110v heater element in my hot water system and blew every 110v lamp that was turned on.

The total amount of damage is well beyond $1500."

Pretty much explains what happened in your case.

I guess that I didn't get down to the reviews

I seem to forget the reviews---looks like I need to tattoo "read reviews on my arm

Would the inverter be damaged as well????

So far the only thing that I see that is connected to the inverter is the frig and maybe the tv/stereo. All of those items are working okay but the outlets that they are normally plugged into do not have any power when the generator was running.

The inverter is a Xantrex Pro XM1800.

fred93 · 07-30-2017, 05:54 PM

Quote:

Originally Posted by Miramar Owner

Yeah, I don't think there is anything in an RV that uses 220. The 50 amp is all 110.

Sorry for your problems with this...it can be heart breaking to experience.

I love this description from Amazon:
Product description

If you ant to use your RV 14-50 plug get power from 6-50 power inlet,

this adapter cord can help you to do it.

NOTE : Should NOT plug this into an RV without surge protected.

GREAT INFO--THANKS LOADS AMAZON

**16ACE27** · 07-30-2017, 06:36 PM

Quote:

Originally Posted by fred93

Would the inverter be damaged as well????

The inverter is a Xantrex Pro XM1800.

Kinda hard to tell from here. Since that inverter has a "pass-through" feature or transfer switch on the AC end it "may" have been damaged by the over voltage condition. If it is running the fridge now the Inverter part is probably OK but the transfer switch may still be damaged and you won't know that until you get the rest of the coach's AC system repaired.

fred93 · 07-30-2017, 11:18 PM

Quote:

Originally Posted by Tfryman

Kinda hard to tell from here. Since that inverter has a "pass-through" feature or transfer switch on the AC end it "may" have been damaged by the over voltage condition. If it is running the fridge now the Inverter part is probably OK but the transfer switch may still be damaged and you won't know that until you get the rest of the coach's AC system repaired.

The inverter is fried--I have 110v goes in but nothing coming out with gen running--plus the inverter control panel is dead

I got 12v coming in but no control panel action!

ComputerChips · 07-31-2017, 02:57 AM

Are there any fuses or breakers that may have tripped to protect the inverter

ComputerChips · 07-31-2017, 03:28 AM

Almost all RV appliances and accessories are 110, so one leg is hot and one leg is neutral. The trouble occurs when the neutral is substituted with the other hot leg in a 220 source. That scenario supplies 220 instead of 110 and is usually a death sentence to any device if it is on at the time.
The electric code determines which prongs in the outlet are hot1 hot2(if applicable) ground and neutral. A welder probably doesnt need a neutral. It would have had hot1 hot2 and ground. You can't "adaptor" your way out of this problem.
If I understand what I have learned a "Hot Dog" is a plug/adapter that is used when you need hot1 and hot2, but hot2 is unavailable on a 30 amp 110 standard RV outlet. The Dog Bone bridges hot1 to both of the hot outlet prongs so you wind up with hot1 hot1 neutral and ground. This allows all devices to have power but no 220 devices will work such as a clothes dryer. Also since you are hooked up to a 30 amp breaker you cannot run everything at the same time.

SuperD · 07-31-2017, 03:47 AM

Go to YouTube, there are several videos that explain Rv electrical systems, look for Rv education 101 with Mark Polk, excellent videos.

Rv 50 amp is basically two 110 circuits, no 220 involved. Pretty sure most everything that runs on 110 in the motorhome will be fried. Sorry, I know this is an expensive lesson, and you're not the first person who has done this!

**EA37TS** · 07-31-2017, 11:54 AM

If you read the Xantrex manual it states that if the inverter is connected to AC power there must be a breaker between the power source and the inverter (20A breaker for the XM1800). You can look at the inverter and see if there are wires going into the inverter on the AC input side as well as a wire connected to the AC Ground on the input side. If the AC input is wired then you may find a blown breaker some where close by.

gmc · 07-31-2017, 01:22 PM

If you have 110 going into the inverter - and nothing out - does sound like the inverter is fried...
The 'inverting' part of the inverter would not typically be providing 110v downstream when the genny is running - its internal transfer switch would allow the genny power to flow through - still in any case since it is internal to the inverter means it likely needs to be replaced.

In giving its life, it likely saved the fridge and anything else powered by the inverter...

Certainly need to check anything else 110v that was plugged in and wasn't on the inverter circuit...

And the biggest additional purchase to make - a surge protector - specifically one with high/low voltage and improper wiring protection... You might have fried the surge protector with this mistake - but it never would have gotten to the RV...
Even the poorly written Amazon description warned to use that...

My 'new to me' home has a welder outlet in the garage - which I noticed was 3 wires (hot/hot/ground)... My research quickly found it wasn't suitable for an RV - so adding a dedicated 50A with hot/hot/neutral/ground is on my list... Currently have a dedicated 30A RV outlet till I get to the project... (need to punch a hole through concrete block and brick for the conduit to exit the garage - the rest is easy... I'm sure the hole isn't difficult with the right tools either...)

I can't picture a scenario where the pictured adapter would be used without causing a problem. Be curious what was really 'bridged' to what in that adapter...

ComputerChips · 08-04-2017, 04:59 PM

A 50 amp RV service does use 2 separate 110 volt circuits, which gives you 220 volts when you make use of them at the same time for an appliance like a clothes dryer that would have a 220 volt outlet and breaker on board. I just learned that there are 2 different types of adapters called a "Dog Bone". One is for reducing a 50 amp 220 volt supply cord down to a 30 amp 110 volt supply. The second one is for reducing a 30 amp 110 volt cord down to a 20 amp 110 volt supply. You can even use both of them end to end at the same time to go from a 50 to a 30 to a 20 amp supply outlet. Having these is handy when needed but you are greatly limited as to how many devices you can use at the same time and you will not have access to 220 volts at all.
220 volts is serious stuff and you should be very careful when trying to connect to somebody's "welder" or "hot tub" outlet. They may not be configured correctly for the RV cord or may not have all of the necessary conductors available.
I included a link. I hope it works.

https://www.youtube.com/watch?v=GoOR2AJGjOI

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