2016 RT CS Adventurous Inverter Wire Fried

[jdbeveridge]

Hi! First time poster here. On a recent trip in our 2016 Roadtrek CS Adventurous, we smelled burning wires when running the inverter so of course, we shut it off. No circuit breakers popped and no alarms sounded which was a bit alarming. Upon returning home and troubleshooting, I found the neutral input wire had burned in two (see picture). On some other posts, I read that this was likely caused by a loose connection. Do you guys or gals agree? Also, Does it look fixable? I started disconnecting the wires with the idea that I might clean up the wires, find a replacement for the melted connection junction (not sure what that part is called), and give it a try. Sound crazy? Or, should I just replace it? Last question: The inverter is a Microcgreen 5000w 24v. The closest replacement fit I have found so far is a Sungold 6000W DC 24V SPLIT PHASE PURE SINE WAVE INVERTER WITH CHARGER. Sungold also has a 4000W version but no 5000W like mine. If this turns out to be the only choice. Go bigger or smaller? Sorry for such a long first post,
JohnB

 

[mkguitar]

Hi & Welcome.


40 amps/5000 watts is alot of power- what do you run with that thing ?
That is certainly more current than the wiring can handle- looks to be 10 or 12 AWG. the minimum for a 40 amp load is 8 AWG



you can replace the terminal block and have new, bright and tight connections and test from there.


If you do replace I would size the inverter to your actual load

 

[jdbeveridge]

Thanks for your input Mike. I'm going to try installing a new terminal block. One more symptom I forgot to mention. After the shore power neutral input burned, we were still able to run the inverter on batteries. The inverter has a cooling fan at both ends. I noticed the fan on the DC connect side was not running but the other one was. Is that normal? Shouldn't both fans run when the unit is on or is there some 'as needed' logic built in?

Thanks again,
John

 

[goodtogo-ClassB]

I had the same thing happen to me. 2017 RT CS ADV. I had a 3K inverter. Not sure why you have a 5K inverter, unless someone replaced it.
I replaced mine with a new 3K inverter from amazon. That was 3 years ago and no problems since.
I would replace your inverter with a 3K inverter, but not sure what type of battery system you have. I have 4 200 AH Lithium batteries. I would not trust your inverter. Your line wires #10 awg copper did not burn but your load wires did. Those #10's are good for 30 amp.
I paid $900 for my new inverter and installed it myself.
Good luck with your project.

 

[ks@yvr]

It looks like your shore power neutral wire broke and it arced across the terminal block. Although the wires look like they may be too small for a 5K inverter as others have mentioned I don’t see why you could not replace the terminal block as the inverter sounds like there is/was no issue with it. Inverter still works off battery since the shore power neutral (solid wire broke). The inverter likely also charges the batteries off shore power (not now, with no neutral) so current charging would only be through the alternator until neutral fixed.

I would determine if a new shore power wire was required and would go with stranded of the appropriate gauge wire to inverter from the shore power junction box as a much better wire choice than a solid single strand (household) wire for a moving vehicle (look for marine wire). Then it sounds like one of the 2 cooling fans may have also died. They are generally a computer fan and the bearings of computer fans get dirty and do tend to seize up over time. Just replace the defective fan and things should be all good. If it was me, I would replace both since if one fan seized the other is probably not far off also seizing up and you will have pulled the inverter and opened it up so do both at the same time. The fans keep the internal components (circuit boards) from overheating and frying circuit boards so it would be a wise preventive maintenance move.

Unless there are other issues with the inverter there really is no need to replace the inverter/charger.

 

[jdbeveridge]

Correction: On my original post I described the neutral wire as having burnt in two and showed a broken wire in the photo which is misleading because I had actually cut the wire in the process of disconnecting the wires from the block. I could not get a screwdriver in the melted neutral connection so I cut it. Does that change anything in your assessments? Sorry about the confusion.

I really appreciate all the feedback and help,

John

 

[ks@yvr]

Correction: On my original post I described the neutral wire as having burnt in two and showed a broken wire in the photo which is misleading because I had actually cut the wire in the process of disconnecting the wires from the block. I could not get a screwdriver in the melted neutral connection so I cut it. Does that change anything in your assessments? Sorry about the confusion.

I really appreciate all the feedback and help,

John

No change in assessment. Stranded wire is best in mobile environments. Incorrect or small wires will lead to heat that could cause a wire failure like what you are seeing.

Ken

 

[Paga]

John,
If you are still looking for the terminal block to replace the damaged one, is there a current rating in Amps molded on it?

Also, what is the overall length and width of it?

What is the spacing between the two holes in it used to mount it to the angle metal on the case, the part we can't see in your photo?

I agree with Ken's comments, you should first restore and test the existing inverter.

Pete

 

[jdbeveridge]

I did find a block rated for 50 amps and have installed it and tested the inverter. Running off battery everything works fine. When I plug into my 20 amp outlet at home, it runs for a while charging the batteries but eventually trips a GFI at the house. I read somewhere that it is not a good idea to pug into a house circuit but I can't remember why. Any thoughts?

Also, the inverter has a large cooling fan on the AC side that is hard wired such that it always comes on when the inverter is turned on. That's working fine. On the other end where the batteries are connected, there is a smaller fan (90 mm) that plugs into a circuit board inside. That fan does not come on when I turn on the inverter. I'm wondering, since it is plugged into a circuit board, if there is some logic that only turns it on when needed. Thoughts?

Thanks to you an everyone helping me out on this,
JohnB

 

[Paga]

I'm not aware of a specific reason the GFI on the house would trip. Is it a receptacle or a GFI circuit breaker in the main panel? Perhaps others have experience with this. It implies there is s small amount of leakage, unless you are actually tripping a GFI breaker in the panel on high current. I assume you are only testing the inverter/charger and all the other RV 120 VAC loads are turned off at present.

An AC clamp meter on that ground power hot lead would tell you total current draw from the house to the inverter. But I do suspect you are just tripping a receptacle GFI and not overloading.... Any idea how much load you have? Input and output currents at the inverter? Other AC loads off the off the ground power would be in addition while plugged in.

The 50 Amp rated terminal block would seem adequate, it should be the same physical size as what was there, if it is that same translucent plastic type.

Regarding the fan, there is often a thermostat that will control one or more fans on these types of power supplies, so if the load is lower perhaps only one will be on 100% of the time. Without a data sheet for that model there's no way to know. Opening it and inspecting the actual fan to see if voltage is applied to it would be one way to know if it should be running.
, and that might be wise if this unit has hours/years on it. There are some fans with air bearings and they may be a better choice due to possibly extended bearing life. Knowing the details for the fans in it would be a place to start. Brand, model, voltage, size, mounting pattern, cfm if that can be determined, etc. Mouser and Digikey have a wide variety of fans, Mouser is here in Ft Worth.

The fan that you haven't seen run could be tested carefully to see if it is OK, which may point to thermostatic or other on-demand control. My Progressive Dynamics 55 Amp charger/supply has two fans that are variable speed depending on the load it is handling and the temperature rise sensed.

Hopefully you were able to really clean up the heavier wires, the larger stranded one looked pretty oxidized. You seem to have a knowledge base going into this about doing this type of repair.. Pete

 

[Paga]

John,

Here is the likely answer to the GFCI tripping at the house when the power converter/ inverter is on in your RV:

https://www.everything-about-rving....the-power-converter-is-tripping-the-gfci.html

Once I read it it makes perfect sense, the inverter / converter has bypassing capacitors in it to suppress RF interference (RFI) the switch mode devices generate. That can result in a low current, which the GFI reacts to as it should.

If one is certain the inverter / converter 120 VAC hot is not faulting to neutral, the RV can be plugged into a non-GFCI-protected receptacle.

I'm just repeating what this article suggests, this is not my suggestion. The receptacles in your RV should have built in GFCI protection, which will be downstream from the house receptacle, so it won't see the leakage at the inverter / converter, I believe.

Here is another possible list of reasons, perhaps not related to the inverter/ converter for the house GFI tripping:

https://www.everything-about-rving.com/why-does-my-rv-keep-tripping-gfci-electrical-outlets.html

This covers troubleshooting the entire RV system for a fault the GFCI at the house may see. You can isolate the circuits in the RV at it's breaker panel.

Pete