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A "potential" or "leakage" may be being produced by one of the plug packs and this is putting a high potential on part of the circuit inside the meter. When you say "blow up, is there any physical damage to the meter or is it simply not-working.
It's the standard "ground loop". The meters probably use the positive input as ground. That's why things get fried easily. A wall wart for each meter would work for you. Putting 3 transformers in a case would work for you.
The component between R1 and C1 looks discolored. Use your nose.
Continuity is not quite what your looking for, but a voltage drop say between the two negative or two positive terminals of where the meters connect.
Ok. I have tested for continuity between the 12VDC common and the 110VAC common. You guys were right on, they are indeed connected, somewhere.
Based on that finding, attached is a new drawing that indicates how everything is wired:
**broken link removed**
This 12VDC power converter is a very large (and expensive) device for providing 12VDC to the entire RV. I have searched and searched and have been unable to find where the two commons intersect. The wiring diagram on the actual 12VDC power converter is as follows:
**broken link removed**
The red circle shows where I have the 12VDC common connected for the signal running to my 0-19.99VDC panel meter. If I measure continuity between this terminal and the common on the 110VAC circuit, I indeed have continuity. From what you guys are saying, this is where the problem lies.
Which lends itself to my question: Is there any other way to get an independent ground for this 12VDC circuit? Other than replacing the panel meters with ones that can handle common grounds, are there ANY other options that you guys or gals can think of at this point? Is there ANY other place I can get an independent common?
Again, I thank everyone for taking their time to help me.
Do you have any wall warts? I ask because I happen to have a whole pile of them myself, and I suspect many electronics hobbyists like myself do as well. If so, you can simply go through them and look for one that has an isolated output. I know for sure that at least some of mine do.
If not, you might be able to find wall warts cheap somewhere, like in a recycled-goods store or other secondhand store.
Otherwise you're looking at something expensive like an isolation transformer. Actually, now that I think of it, you could probably do this on the cheap. There's a guy with a bunch of circuits on the web who uses a very simple but clever scheme: he puts two low-voltage transformers (like 6.3 or 12.6 volts) back-to-back, so you get 120 volts in and 120 volts out. That would definitely do the trick. (Just be sure to follow good wiring practice, especially on the "secondary" side of the 2nd transformer.)
Do you have any wall warts? I ask because I happen to have a whole pile of them myself, and I suspect many electronics hobbyists like myself do as well. If so, you can simply go through them and look for one that has an isolated output. I know for sure that at least some of mine do.
If not, you might be able to find wall warts cheap somewhere, like in a recycled-goods store or other secondhand store.
Otherwise you're looking at something expensive like an isolation transformer. Actually, now that I think of it, you could probably do this on the cheap. There's a guy with a bunch of circuits on the web who uses a very simple but clever scheme: he puts two low-voltage transformers (like 6.3 or 12.6 volts) back-to-back, so you get 120 volts in and 120 volts out. That would definitely do the trick. (Just be sure to follow good wiring practice, especially on the "secondary" side of the 2nd transformer.)
Yep, I have a bunch of them also. But what I am having trouble understanding is how will finding one with an isolated output actually help this situation? Isn't the actual problem due to the fact that the 110VAC and the 12VDC power converter share common? How would using an 9VDC wall wart to power the panel meters help this issue?
Please bear with me as I try to fully comprehend this issue.
As for your other solution using the back to back transformers, I am not exactly sure what I need to purchase or how I would even wire it. Could you elaborate some more to help me understand?
Doen't sound like your RV will be hitting the road anytime soon, or acquiring a battery? I can say ditching the old Magnetek Converter in the camper, for a new 3 stage Progressive Dynamics was a really good move. You can have the Magnetek transformer for shipping if it will do any good?, it weighs a ton.
Doen't sound like your RV will be hitting the road anytime soon, or acquiring a battery? I can say ditching the old Magnetek Converter in the camper, for a new 3 stage Progressive Dynamics was a really good move. You can have the Magnetek transformer for shipping if it will do any good?, it weighs a ton.
Actually, the RV will never really hit the road. It was purchased as a way for allowing my handicapped son the ability to sleep "outside" (in the backyard) as well as having his own little enclosed fort (it is a small camper) with his toys, games, TV, and refrigerator in a climate controlled and bug free environment. It will also allow us to take it to family events that provides him a place to go where he can be in comfort and allow him to relax a bit. The panel meters were to simply keep an eye on the power status of the various circuits as well as looking pretty cool.
Just seems that I cannot overcome the common issue without replacing the existing devices.
Yep, I have a bunch of them also. But what I am having trouble understanding is how will finding one with an isolated output actually help this situation? Isn't the actual problem due to the fact that the 110VAC and the 12VDC power converter share common? How would using an 9VDC wall wart to power the panel meters help this issue?
Please bear with me as I try to fully comprehend this issue.
Sorry, brain fart on my part. You're absolutely right, the problem lies with your 12 volt power supply. Changing the 9V supply won't help. Sorry, didn't mean to get your hopes up. I have no solution at this point, apart from an isolation transformer before the 12V supply.
How much current does the 12V converter supply (or did you already tell us? I can't see the whole thread at this point)?
I see now; 50A meter, so figure at least 600VA, so you probably need a 1KVA isolation transformer, not cheap.
All "Plug Packs" "Wall Warts" MUST have total isolation between the input and output. Otherwise they are of no use AT ALL. Your item is obviously FAULTY.
Read-up on the principle of these products to see how they work. Some of the other posters are leading you astray by their comments. You are also being misled by your interpretation of “COMMON EARTH” or “COMMON GROUND.” This does not refer to or mean the input and the output has a “COMMON CONNECTION” or a zero resistance path between one of the leads of the input and one of the leads of the output.
If there is a low resistance or even a HIGH RESISTANCE, between input and output, the product is FAULTY.
Colin is no doubt correct. However, some of the fault for the confusion here is mine, since I mistook the culprit here to be the 9-volt wall wart, not the 12-volt supply (which is apparently not a wall wart, but a high-current supply). So my apologies.
I sort of guessed that when checked the grounds would be found to be common to each other. The problem is the meters being used that are powered with low voltage DC do not allow for the configuration they are being used in. The AC current meter which functions is pretty much proof of that. I would have thought based on the fact that the 9 DC volt wall wart should provide isolation for the power of all meters but apparently there is more to it. Despite it being an added cost and inconvenience my only suggestion, as it was in the beginning, is to use meters designed for this that have isolated inputs. The only other possible viable solution might be to use a DC to DC converter with isolated input / output similar to the Cosel ZUS101212. The cost of using a good DC to DC converter is the cost would outweigh buying two new meters of the correct type for the application. Meters of this type use very, very little current so maybe a cheaper isolated DC / DC converter could be found and used?
While not an RV guru my buddy had one with the same setup. When running on shore power or the generator it relied on a huge 12 volt power supply that delivered 40 amps or more. When neither was available it relied on 12 volt battery power from a few deep discharge marine type batteries.
I want to thank everyone that has helped me through this. It is greatly appreciated.
After spending hours going through each of the circuit commons running to the 12VDC power converter, I finally found the offending circuit. This common would provide continuity between the 110VAC circuits and it ran directly to the 12VDC power converter commons. I have NO idea where this wire runs to, but I have disconnected it and now have all three panel meters running (luckily I purchased a spare of each). They all work perfectly now.
As stated, I am not sure where this wire runs to, but everything that I need seems to work fine. I just left this wire (white) off and wrapped it with electrical tape. I would have assumed that something on the 110VAC side would not be working without this common connected, but everything 110VAC and 12VDC works that I need to work.
I checked continuity with this offending wire disconnected from the 12VDC power converter and it does indeed provide a connection to the 110VAC commons. Not sure why or how.
In any event, if anyone sees any further issue with it running safely like this, please comment. Otherwise, I thank each and every one of you that helped me locate this issue.
Interesting. I would love to see a wiring schematic / drawing of the whole system. Generally speaking, the AC lines should be Green (Ground) White (AC Neutral) and Black (AC Hot or High). In residential the Neutral and Ground are tied at the entry (breaker panel). This is done for safety reasons and for compliance to NEC code. Anyway, sans a wiring schematic it is hard to say where it goes (the now disconnected wire) so I can't comment on it. It was apparently there for a reason, and connected to ground but I don't know why. Glad it works OK and as time allows maybe you can find out exactly what that wire was for.
I checked continuity with this offending wire disconnected from the 12VDC power converter and it does indeed provide a connection to the 110VAC commons.
Without even considering you problems with the meters, that wire connection in itself is serious safety hazard.
There should be no connection between the mains supply and the low voltage output of your 12volt power supply.
I can only assume that someone at sometime in the past intended to make a connection from the 12v side of the system to safety earth and made a bit of a marmelade of it.
The possiblity existed for all the 12v wiring to be at 110volts above ground, not a good way to be.
Without even considering you problems with the meters, that wire connection in itself is serious safety hazard.
There should be no connection between the mains supply and the low voltage output of your 12volt power supply.
I can only assume that someone at sometime in the past intended to make a connection from the 12v side of the system to safety earth and made a bit of a marmelade of it.
The possiblity existed for all the 12v wiring to be at 110volts above ground, not a good way to be.
Yes, but just to be sure, you should check your RV's electrical system with a meter to make sure it's OK. It sounds like you know how to do this, correct? You want to make sure there are no what are euphemistically called "stray voltages" to bite you.
Yes, but just to be sure, you should check your RV's electrical system with a meter to make sure it's OK. It sounds like you know how to do this, correct? You want to make sure there are no what are euphemistically called "stray voltages" to bite you.
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