Converter Failed and Passed 220 to RV

[YDrive]

Late this evening we were using the microwave and the power too our unit went out. We reset the breaker thinking it was a blip at the campground. The power came back on, but nothing in the unit but the 12v items worked.

I checked the kitchen outlet and it showed 209v. At this point I am lost. No clue what happened but I assume everything in my camper is ruined.

There was no warning sign before this just happened it if the blue. I am have been unable to find anyone else talking about a failure like this.

Any thoughts? Will my insurance cover this? We are sleeping in it tonight with all power off for safety and will try to limp it home in the morning.

[JimD]

Very strange that this happened while you were already connected. Usually a mis-wired outlet will be the cause of 220 getting into where it shouldn't.

You didn't mention what service you were connected to, be it 50 amp or 30 amp. In any event, I would recommend using a power cord adapter to connect to a standard 120 volt outlet and then measure what is going on with outlets and the other 120 volt items. You may want to verify the 120 volt outlet with a meter before plugging in just to be sure.

Only items that were powered by 120 volts would possibly be damaged. That would be the converter, microwave and TV. If the water heater was switched to 120 volts and it called for heat, you could have fried the heating element. Same with the fridge if it called for cooling while in the 120 volt mode. Air conditioners should be OK as long as they were off.

[YDrive]

It was connected to 50 amps at the time. The ACs were both off thankfully but the fridge and water tank were both on AC power at the time. We have been here 8 days and no trouble until today. I have an EMS plugged into the pole and it showed no issues.

I am assuming the problem is between my EMS and my converter due to this. I guess it could also be my cord or plug but it was random as I mentioned.

[Onyrlef]

Originally Posted by YDrive

Late this evening we were using the microwave and the power too our unit went out. We reset the breaker thinking it was a blip at the campground. The power came back on, but nothing in the unit but the 12v items worked.

I checked the kitchen outlet and it showed 209v. At this point I am lost. No clue what happened but I assume everything in my camper is ruined.

There was no warning sign before this just happened it if the blue. I am have been unable to find anyone else talking about a failure like this.

Any thoughts? Will my insurance cover this? We are sleeping in it tonight with all power off for safety and will try to limp it home in the morning.

What is meant by "random"? The 50 amp pedestal is two 50 amp 120v hot legs a common and a ground. The ems, RV plug and RV pigtail are the same. Your converter is only swapping AC to DC. The point being it either is or it ain't, somewhere along the line 240v got by your ems, rv plug, pigtail and distribution panel or you're making 240v somewhere along that line and it's randomly going to keep doing so until you sort out where it's occurring.

[ARoamer]

OP didn't post RV type / model, I'm curious about this.
Is it even possible a stuck contact in the transfer switch could cause this?

[Onyrlef]

Originally Posted by ARoamer

OP didn't post RV type / model, I'm curious about this.
Is it even possible a stuck contact in the transfer switch could cause this?

As am I now, not sure if the automatic transfer switch could be a factor unless the onboard gen. is running while shore power is hot. Furthermore, I'd like to know where he's camping in June with both A/C's off, so I can pack up and head that way. It was 104 in Plano, America yesterday.

[YDrive]

It is an Octane T32C. It is wired for a generator with an automatic transfer switch but there is no generator. We are headed home, I plan on sitting down with a meter and starting at the plug on 120 and seeing where the failure started.

We were in the middle of a busy summer of camping. My son is devasted as an 8 year old, but I really want to track down the issue and see what my options are from there.

[norty1]

Read up on a " Open Neutral" condition in your 50a ac supply. This can cause the condition you describe.

[Onyrlef]

Originally Posted by norty1

Read up on a " Open Neutral" condition in your 50a ac supply. This can cause the condition you describe.

It's most definitely an open neutral, i.e., it's making excessive voltage somewhere, the question being where. Furthermore, it's quite dangerous, a loose neutral heats up and can cause a fire.

[Midnightmoon]

I may have missed it, but did you check the voltage output of the campground service itself and/or at the output of your EMS?

[YDrive]

Ok we arrived home and I had a little bit of time to troubleshoot.

Before we left I did check the voltage at the post and also the output of my EMS. The EMS did not indicate a problem and between the two hots and the neutral I was seeing right around 123v.

Once arriving home I removed the plug from the side of the camper, the factory wires on the back were tight with no sign of any issues. Also, the pins on the front appear fine no melting or arcing there either.

Since we dont have a generator, I bypassed the automatic transfer switch and went from the outside RV plug right into the converter. I am using a 50amp to 20 amp adapter, as I do not have any outlets within easy each of the camper.

With all breakers in the converter off (I am using this term generally since the converter/breaker box are combined in my my unit) I see 123v between the two hots and neutral. Once I turn on the breakers in the unit I see between 4 and 10v between the hots and neutral. The converter does not appear to be serviceable and I do not see any signs of wire melting or smell anything unusual in the cabinet around it. I am guessing this is going to be a power distribution/converter issue based on what I have seen so far.

This all took place in about 15 minutes late last night and we slept with both the battery off and the RV unplugged for our safety.

I will be back at it later today, if there is anything that I can check to narrow it down further.

Thanks for the input so far!

[craigav]

Not that it matters much, but for clarity I would simply use the words "breaker panel" and I say this because the "converter" in that combined location cannot cause the issue you have described. Also, when speaking of the adapter you are using, start with the source side (pedestal or home outlet) as there is some relevance to the difference in regards to what you are encountering. In this case you are using now a 20a to 50a adapter, which I will explain why this is relevant, and not that I am a stickler to proper terminology, just that it helps with the clarity of the situation.

Your setup is a 50a unit and in your power cord you should have (most commonly) green, red, black, and white wires. When you are plugged in to a properly wired 50a outlet, measuring the voltage between the red and black should read ~240v, and when measuring between either the red or black and the white (neutral) the voltage should be half of that amount or ~120v. The only way an outlet in your RV can rise above the 1/2 amount (~120v) is if the white wire has lost its connection somewhere between the breaker panel and the source of the power (in your case likely between the breaker panel and the end of the power cord, but in other cases the problem could be before the pedestal) as the white wire is the neutral. For this reason you need to carefully check the white wire from the cord's end all the way to the breaker panel for a loose connection as that is really the only likely possibility for what you are describing.

In addition and why I referenced the adapter, when using a 20a to 50a adapter, your source is only 120v to start with and that adapter combines the red and black wires, which means when using that adapter, the voltage between the two hots (black and red) should be extremely low (single digits if even that) and the voltage between either the black or red to the white (either hot to the neutral) should be the same as the incoming line voltage (~120v).

So while you can certainly follow the white wire and check it's connections, the issue with having the ~209v at an outlet cannot occur when using the adapter so knowing this can help you determine that just because the voltage "may" appear proper now (now being when using the adapter), that doesn't mean the issue is resolved.

When you stated "Once I turn on the breakers in the unit I see between 4 and 10v between the hots and neutral." I am taking it that you are saying that you were using the adapter at the time of this measurement which again means that both hots are tied together at the adapter, and there shouldn't be much if any voltage between the hots (red and black), however there should be the full voltage (120v) between either hot and the neutral. The failure to obtain the ~120v between either hot wire and the neutral is the same condition that would cause the very high voltage reading you originally observed when plugged into the 50a service.

Again, all of this information leads to only one conclusion, your neutral wire (white on the power cord but possibly a different color at the breaker panel although it should be white), has a bad, missing, or poor connection. What I would suggest is to start back at the transfer switch as that should be where the power cord first connects, find the white wire, and check each and every connection that it has between the power cord and the breaker panel. If you don't find the location where the connection is bad, then if you have a voltage\ohm meter that can be used as a tool to help you locate where the problem is by checking the continuity (ohm, resistance), however you don't want to do that with any power plugged in as that could ruin the meter. In fact, you don't want to even trace the wires as I suggested with the RV plugged in.

If you find an issue with the Neutral white wire and correct it, then the voltages between the two hots when using the adapter should be extremely low and the voltage between either hot and the neutral should be the ~120v, however without an adapter and when plugged into a proper 50a outlet, the voltages between the two hots should be ~240 and from each hot to the neutral ~half that amount.

Feel free to share what you find and best of luck, ~CA

[Onyrlef]

Originally Posted by craigav

Not that it matters much, but for clarity I would simply use the words "breaker panel" and I say this because the "converter" in that combined location cannot cause the issue you have described. Also, when speaking of the adapter you are using, start with the source side (pedestal or home outlet) as there is some relevance to the difference in regards to what you are encountering. In this case you are using now a 20a to 50a adapter, which I will explain why this is relevant, and not that I am a stickler to proper terminology, just that it helps with the clarity of the situation.

Your setup is a 50a unit and in your power cord you should have (most commonly) green, red, black, and white wires. When you are plugged in to a properly wired 50a outlet, measuring the voltage between the red and black should read ~240v, and when measuring between either the red or black and the white (neutral) the voltage should be half of that amount or ~120v. The only way an outlet in your RV can rise above the 1/2 amount (~120v) is if the white wire has lost its connection somewhere between the breaker panel and the source of the power (in your case likely between the breaker panel and the end of the power cord, but in other cases the problem could be before the pedestal) as the white wire is the neutral. For this reason you need to carefully check the white wire from the cord's end all the way to the breaker panel for a loose connection as that is really the only possibility for what you are describing.

In addition and why I referenced the adapter, when using a 20a to 50a adapter, your source is only 120v to start with and that adapter combines the red and black wires, which means when using that adapter, the voltage between the two hots (black and red) should be extremely low (single digits if even that) and the voltage between either the black or red to the white (either hot to the neutral) should be the same as the incoming line voltage (~120v).

So while you can certainly follow the white wire and check it's connections, the issue with having the ~209v at an outlet cannot occur when using the adapter so knowing this can help you determine that just because the voltage appears proper now (now being when using the adapter), that doesn't mean the issue is resolved.

When you stated "Once I turn on the breakers in the unit I see between 4 and 10v between the hots and neutral." I am taking it that you are saying that you were using the adapter at the time of this measurement which again means that both hots are tied together at the adapter, and there shouldn't be much if any voltage between the hots (red and black), however there should be the full voltage (120v) between either hot and the neutral. The failure to obtain the ~120v between either hot wire and the neutral is the same condition that would cause the very high voltage reading you originally observed when plugged into the 50a service.

All of this leads to only one conclusion, your neutral wire (white on the power cord but possibly a different color at the breaker panel although it should be white), has a bad, missing, or poor connection. What I would suggest is to start back at the transfer switch as that should be where the power cord first connects, find the white wire, and check each and every connection that it has between the power cord and the breaker panel. If you don't find the location where the connection is bad, then if you have a voltage\ohm meter that can be used as a tool to help you locate where the problem is by checking the continuity (ohm, resistance), however you don't want to do that with any power plugged in as that could ruin the meter. In fact, you don't want to even trace the wires as I suggested with the RV plugged in.

If you find an issue with the Neutral white wire and correct it, then the voltages between the two hots when using the adapter should be extremely low and the voltage between either hot and the neutral should be the ~120v, however without an adapter and when plugged into a proper 50a outlet, the voltages between the two hots should be ~240 and from each hot to the neutral ~half that amount.

Feel free to share what you find and best of luck, ~CA

Come to think of it, I'd bet a nickel CA is spot on and your loose neutral is in the transfer switch. Even w/o a gen. the unit was likely pre-wired for one. If that neutral is loose it fed excessive voltage ( not necessarily full 240v) via the ground to the dist. panel and/or to every other ground in the rv. Unplug from shore pwr. and just start checking those neutrals (transfer sw. and dist. panel), if it was loose then, it will be loose now.

[YDrive]

Ok, I am now at a computer so let me try to type a little better what I have tried and what I will try later today.

As of right now, I am using an adapter to 20 amp at home. The issue occurred at the campground while it was connected to 50amp that had worked without issue for approximately 8 days. This is where the 209v was seen at the outlet in the kitchen.

After getting home, I checked the outside input plug for the RV. There is no sign of scorching, arcing or overheating. I also pulled it out of the side of the camper and it seems fine also on the back side.

The wire that goes from the back of the RV input is only about 5 foot long and is now connected directly to breaker box (thanks for the terminology recommendation, its been a long 12 hours). I bypassed the transfer switch as it is automatic and I didnt want it to factor into any of the other testing I did. I can reconnect it later or just bypass permanently as we dont use a generator for now.

I tested the input extension cord from house and it functions as expected with 123v between the single hot wire and neutral. I then connected it to my adapter that went into the RV. I went around to the inside with all breakers off and observed (all of these tests were done with the cover off at the screw on the main 50 amp breaker and neutral bar itself)

Red to White 123
Black to White 123
Red to Black I will test this later today

After turning on the breaker box I observed
Red to White 10v
Black to White 4v
Red to Black I will test this later today.

I will investigate that input wire some more, but there are no loose connections in the breaker box as I have checked those, and I already disconnected the transfer switch so its wired from the RV input directly to the breaker box. Unless the RV input has failed or the wire has broken can the breaker box itself fail internally? My RV just like many others I am sure is an absolute disaster behind the breaker box. I will need to stand on my head and check every inch of that wire for any type of issue. The camper is 4 years old and we haven't had any issues with it yet like this.

My original thought late last night was maybe it was the 50 amp shore power cord itself, but with the low voltage when the breaker box is on even with the adapter, it seems I can replicate this issue even at home without the 50 amp chord or plug in play.

Does the fact that the voltage drops only when the breakers are on indicate anything within that breaker box itself?

Thanks!

[craigav]

I have never seen a breaker box fail, however that is simply words as I certainly have seen a connection become loose within a breaker box, and I have seen damaged breaker boxes due to a short. In this case though, that isn't the issue. The reason (most likely) that you read the proper voltages prior to turning on the main breaker is similar in concept to a poor battery connection in a vehicle, where in such cases you turn the key on and the dash lights up then when you go to start the vehicle, then nothing. Clean the cables and connections and all is good again.

In your case, what you are describing would lead me to believe that the neutral (white) is actually connected, however it is not connected well and as soon as any current starts to flow the connection breaks down.

With this in mind, and to add more specifics, start back at the main power inlet as you checked and recheck the white wire, then move to the transfer switch (if you don't have an ems prior to the transfer switch, if so check the ems connections then transfer switch), then finally to the neutral bus bar which should have one of the larger (if not largest) white wires that connects back to the main power inlet's white wire. You really don't need to mess with the "rats" nest of wires, at least not at this point as even though there are a lot of wires, there shouldn't be any breaks in the neutral in that nest, just check the endpoints, breaker box neutral bus's white wire from the power source, the transfer switch (make sure it has no connections whatsoever and is 100% bypassed) and the EMS (if you have an internally wired ems) and then the plug on the side of the RV where you plug into. Keep in mind, that just like a battery cable connection, it may appear to be well connected but still isn't making a good connection, if a quick check doesn't reveal a poor connection, then remove, inspect, clean, and re-install the white wire at each possible location insuring a tight connection at each location. Then recheck the voltages. ~CA

[craigav]

BTW, from what I have read, I assume (lol) that your RV has a male power inlet connection on the side of the RV, not that it matters in particular, but I have seen where a power cord itself has a broken connection (or almost broken) and commonly that problem is at the power cords plug location. Many times and almost all the time the cord's plug is a molded and is a sealed connection where you can't inspect it visually. I discounted this possibility as I believe I understand you are saying that you bypassed that power cord as well in your testing? However and if not, certainly an RV power cord's plug could also cause this type of issue where the white (neutral) in the plug has broken\degraded over time.

The next steps would be to check the resistance of each connection if the previous checks do not result in finding a poor connection. I can explain how to do that if needed, so feel free to share the results of your testing, not to mention sometimes the checking for resistance as I described doesn't reveal any issue as your connection may be (as it sounds to be) in place when little to no current is flowing, just not when there is current flowing. In such a case checking the voltages along the path would be needed and while plugged in, however that is more dangerous to do if you are not very careful and not what I recommend to do at this time.

~CA

[YDrive]

I found the problem. The neutral wire on the backside of the RV plug was loose and starting to melt. My son was there helping me this time so I got a better look. I tried to attach a picture.

So I will get a new one and hope nothing too bad is destroyed. We tried the 3 tvs and they all power on from an extension cord so here is to hoping. Thanks for talking me through some various options.

This will be added on the list of things to check everything spring when dewinterizing.

[craigav]

Good deal

[Learjet]

That is why I installed my EMS right before the breaker box...to catch an open neutral in my cord real, transfer switch...etc.

As you found out, bad things happen on a 50 amp service when you lose the neutral, then an unbalanced load on L1 and L2 causes the voltage to rise on one leg.

[craigav]

Just another thought to share.

When you replace your receptacle, these screws need to be tight (not the screws with the arrows, the screw that is highlighted in the red box and those like the one in the red box), however they don't need to be overly tight as that could strip the threads which I wouldn't be surprised is what happened and at the factory and that the neutral connection was over-tightened and resulted in a bad connection with time.

I have never seen the torque value listed for these connections, however I suspect they are to be torqued at around 40 inch lbs. Of course most people including myself do not have a torque screw driver, but if you have a small torque wrench that is in inch lbs and can hold a screwdriver bit that would work.

Short of that, I would suggest prior to removing the damaged receptacle, get a feel for how tight the existing connections are so that you can try to match that with the new receptacle, you don't want to be too tight as that can strip the threads, and of course you don't want to be too loose either.

Also, check the existing wires, you may need to cut them back and re-strip them to get to good copper again.

~CA