Looking to buy new converter/charger need suggestions?

Hi,
  I own a 1987 33 ft Monitor which currently has a Light Power Systems auto transfer switch (LPT30), and a B-W Manufacturing Inc converter/charger, Model 3240UL (or is that a D rather than an 0?). Other markings on it read: code 447, Series 3200 (again, are those zeros or Ds? It is very hard for me to get my head in that space to read the label ), 40 amp, out 120V 6.2 amp. As far as I can tell, there is NO fan on this unit? This unit is connected to a wall outlet.
This is all connected to 3 12v deep cycle batteries at the other end and side of the rig.

I did just purchase an RV electrical systems book, but it's going to take a while for me to get through. I am familiar with automotive 12V systems, AND common 120V house wiring, so I'm hoping the RV's electrical systems won't be to much of a stretch to understand

I am looking to replace this setup, (not the batteries as they are fairly new) and need some "expert" opinions. I hope to eventually add solar power to the rig, so I guess I am at first asking if there is an affordable converter/charger that will also work with the future solar system, and if not, a decent converter/charger under $200 to replace this old setup?  Will I also need a new transfer switch or in newer models are the transfer switches combined in the units?

I am not sure if the current electrical problems I am having are due to the age of the converter or something else entirely, but seeing as I eventually want to full-time in the thing, I am replacing and repairing all that I can BEFORE that time comes.

As for the "issues". I am plugged in all of the time, with a 15amp adaptor (the RV has a 30amp system), in the hopes of keeping the batteries charged and occasional use when I'm out there working on the thing.
I just had to replace the two exhaust fan/vents in the RV. One in bathroom and second is in main living compartment over the kitchen/dinette area. (the older fan in bathroom failed so I figured if I was replacing one, I may as well replace both at the same time.) I went with SHURflo Comfort Air Fans, one silver in bath and the gold version in other area.

While both fans running for exhaust seemed to work fine on the older fans (which were tiny in comparison) earlier in the year, when I leave these new ones on I come back to only one fan running, or occasionally BOTH fans will stop running (the battery charge indicator located over the entrance door will show the batteries as being charged when this happens). I was hoping to leave the fans running most of the time at least until the end of August, since it's easily been getting to 100-110 degrees in there during sunny days.

I don't think BOTH new fans can be faulty, so it MUST be an electrical system problem? Might the problem be the converter charger overheating due to the internal temps and it having no fan, therefore possibly not charging the batteries enough to keep both fans running (but why then sometimes does ONE fan continue to run, and battery indicator says all is well?)

Also, this RV has ONE GFI outlet in the bathroom, and that breaker seems to "trip" quite often when I plug the RV back in, or on the few occasions where the outside circuit breaker has tripped and then I reset THAT one. The RV is plugged into the same circuit (a 20amp breaker in the panel) that a swimming pool filter is on. Since nothing but the converter is running on AC in the RV, this doesn't usually seem to be causing a problem unless I forget to check  whether that filter is on before trying to use the AC in the RV or on the one occasion that the RVs electrical plug got dislodged .

Also, the 12v lighting in the RV is noticeably dimmer when the RV is unplugged.

I know this isn't the ideal electrical setup, and I am considering wiring a separate 30 amp circuit for the RV if I can determine if I am staying put long enough to make it worth the effort. (I am using a relative's  electrical connection, and it would take attempting to re-wire a 30 foot underground run to do this   )

I realize that this is a very wordy, multi-part question, and I appreciate the effort it takes to read and reply to this.
Please let me know if there's any way for me to clarify the issues!
Thanks!!

The transfer switch has nothing to do with the converter - it switches 120v power between the generator and shore power. Is the monitor a motorhome or towable, and is it equipped with a generator?  Some inverters have a built-in transfer switch as well, to shift power source from shore power to inverter and back.

There are  variety of converter chargers available - Best Converters.com has a selection. I suggest a three stage type if the budget can handle it. Progressive Dynamics is a popular brand and has decent tech support available if needed. The converter doesn't really have anything to do with solar either - solar panels are an alternate source of charging that will have their own wiring and voltage regulation. Both can be hooked to the battery bank at the same time.

I can't imagine what is shutting down one or both of your fans. Almost sounds as though an auto-reset 12v circuit breaker is tripping. Or maybe an thermal cut-off in the fan itself (seems unlikely in a fan)?

Dim lighting when unplugged from shore power suggests  a weak battery. Have you checked the water in the cells lately? Had it load tested? How old is it?

Re the GFI, when you say the 'breaker' tripped, are you talking about the GFCI opening or the circuit breaker for the entire circuit? If the GFCI, I would start by replacing it. It's not expensive and that would rule out one set of possible problems.

I do not know  your converter personally but this info is generic.. First a bit on the difference between Automotive and RV wiring..

If your RV is a motor home it has a "Truck" (Automotive) part and a "House" part, Trailers have a "Vehicle" part and a "House part (The vehicle part is the exteriour lights (makrker/stop/turn/tail) and brakes)

In the automotive world, though there is truly not a standard, tradition has it BLACK is ground, Same in electroincs where my training lies.

In a HOUSE.. Black is HOT  and at the main service panel (The park's not yours) White and Ground are bonded so many folks think of White as ground, (it is not)

Thus on the 12 volt side of yoru RV, white is often ground, and black hot.

That is the warning: USE A METER TO BE SURE please.

Now your problem.

Low voltage can cause a fan motor to stop fanning,  So can excessive heat seizing up a bearing.  On older motors those are suspects 1a and 1b.  bad switches are #2.

Your voltmeter is your friend.. If you put the meter on the batteries and it says someting like 12.6 after sitting there plugged in all night.. bad converter.. If it says 13.6 Well. then read on... Turn on fan. If the meter continues to read 13.6 good converter, if it goes 13.5.4.3.2.1 12.9.8.78.6.5.4  Bad converter.

What to do if the converter is bad.. Well there are many converters.. In the old days theu used to make one where when I hear of folks who have it my advice is UPGRADE.. On the other hand Damon gifted me with a Progressive Dynamics 9180+ charge wizard, Equivlant of the 9280, and from the PDI 9200 line, there is no upgrade.. The last two digits depend on what you have for batteries

For a pair of GC-2 Golf car batteries 60-80 is about right (70 is perfect)  Smaller batteries,  Well a pair of Group 24's would be a 9245

Gary,
  Thanks for the info on this transfer switch. I now understand what it's purpose is I thought I had read something somewhere about transfer switches shifting from shore to inverter as you mentioned, and that's what I assumed this one is for.
The motorhome is a Class A type, and does have an Onan genset onboard. I forget the model number off the top of my head.

As for asking about the future solar setup. I haven't read enough about them yet, so I was not sure if they connected directly to the currently installed converter, and didn't want the expense of buying an expensive new converter now only to have to go with a different type once I made the switch to solar.

Yes, those fans are behaving VERY oddly. I could see if they were on separate circuits and one or the other was resetting, but they are both on the same circuit. You wouldn't think a fan would have a thermal cut-off, as it's PURPOSE is to remove heat. And 110 degrees or less is in reality not all that hot. (the thermometer is hung fairly close to the ceiling, so it's pretty accurate for up there)

I did check the water levels on the batteries and they are fine. There are THREE 12v deep cycle batteries. One battery is less than a year old, the other two I was told should be less than two years old.

And I'm sorry for the GFI confusion. Yes, it's the GFI itself that I have to reset. I will try the replacement.


John,
Thanks for the basic RV wiring tutorial. I thought that maybe there was a low voltage issue to the fans, but I'm stymied as to why one should keep running and not the other. And it's NOT always the same fan that quits first. Very strange behavior as mentioned before

If I can get some time tomorrow with no rain, I will do the battery tests. I am still wondering if it's a heat issue with the converter, as it's pretty warm in that compartment, and as I said, as far as I can see there's no fan on the unit. I can always wire in a decent sized 12v computer fan in there, as the fuse panel is right up front and has an open slot or two. The only problem there is that it would always be on unless I also install a manual switch.

The only problem there is that it would always be on unless I also install a manual switch.

Click to expand...

or... install a thermal switch along with it!!!

Alfa38,
  Thanks for the "DUH" moment. I've installed those on PCs, so not sure why I didn't think of that.

As for the battery tests. Got about a 13.43v on battery bank after being on charger all night and kept just about the same voltage after fans were turned on. So I guess I can assume that at least at that time the converter/charger was working correctly.

What was interesting is that later on I removed the ceiling shroud from the fan and checked the voltage being supplied to the fan itself while it was running (and it was doing that odd running slower than normal thing even though switch was turned to full speed), and I was getting a lot of voltage fluctuation (sorry, I forgot the exact number but the difference was at least 1/2 - 3/4 V?). So I guess this older converter doesn't do a great job of "purifying" the DC voltage. Are the new Progressive Dynamics ones better at it?

Still not sure that the fluctuation is the cause because I would image then that BOTH fans would have the same problem at the same time as they are on the same circuit, but they don't. It seem to be either one or the other, very rarely both. I'm going to have to try calling the manufacturer and see if this is a common problem with these units.

Tried changing the GFI and I could not get the new one to "un-trip"... instructions said that are factory set "tripped" and will not unlock unless correct power is supplied. Triple checked the wiring and it IS done correctly. Re-installed original GFI and that one worked fine (for now).

SO...either I keep getting new parts that are faulty, something is VERY wrong with the electrical system somewhere, or I have gremlins.

I vote for gremlins.

Hi,

You said that your converter was plugged in. If so, it may be on the GFI circuit and actually be causing the problem. Try unplugging the converter. I'd also check the battery voltage to be about 12.6 Vdc after resting for an hour or more (or with a small drain on them) without the converter plugged in/turned on.

I'd also note that batteries should be replaced in sets, not one at a time.

Ernie

I realized at that voltage it was still charging..is it NOT supposed to do that?

I did not get any fluctuation readings off the battery banks itself..

Yes, I'm positive the fans are on the same circuit, as i pulled the fuse to install the new fans. If memory serves the two light fixtures on the ceiling in the kitchen area are also on the same circuit. The wiring connections are clean, so unless there is a fault in the wiring somewhere in the ceiling.....

And again, I triple checked the wiring (load/line) on the GFI circuit to make sure it was oriented correctly. I forgot that there is an outside outlet that I believe may be on the GFI circuit (I've rarely used it, so easy to forget it's there), so I will see if THAT one might be getting damp.

As for the fan problems...I now have the sneaky suspicion that ShurFlo already knows these units have problems. I called this morning and didn't have to go into much of an explanation of how they were behaving before the tech talked me through the trouble-shooting steps to see if it's a bad controller board or motor on both (and an offer to send out the new faulty part when I figure out which one it is). She didn't seem tho think it was odd at all that I had TWO units that didn't work properly. There's no way they had that info handy, and were so ready to replace, if they hadn't already dealt with this issue on more than one occasion

I may not get to test them until tomorrow.

Sorry it's taken so long to get back here, but the rest of life got in the way of me working on  this.

I was only able to do a quick test today to see what other items may be on the circuit with thew two fans, and the ONLY other items on this 12V circuit are two  double bulb overhead light fixtures.

So I am going to start with this question first.....this happens when I am plugged in to shore power on a 15A circuit (all that I have available at the moment)

Should the voltage drop as I turn on each item in turn? For example, with NONE of the four items turned on I get a reading of approx 12.4 volts at one fan connection. As each of the four items are turned on there is approx a 1/2V drop in the reading. So, when both fans (turned up to max speed) and both light fixtures are on at the same time, my voltage reading is now somewhere around 10V.

Is even this correct? (I didn't have a chance to see f it behaved the same way with shore power disconnected)

15A shore power is plenty to power your converter/charger as long as nothing else is using it (fridge or water heater) - it doesn't need more than about 4 input amps to produce its max output.

No, the DC voltage should not drop as you turn things on. The converter should be able to supply all four of those items easily. Voltage should stay around 13.3-13.6.

Gary,
  Thanks once again. There should be no other draws on the system as it stands right now, save for phantom draws, (there is definitely nothing else on this particular circuit). I am unclear as to whether the 12V board on the fridge uses any power if the fridge is off, same for the water heater, etc.

Just to be clear, I am testing the voltage at the + & - connections to the fan, the one easily accessible spot. I will try to get a chance to run the same test tomorrow on 120V unplugged/ battery only power  if anyone thinks that'll make a difference.

One more question if you don't mind, as I am unclear on exactly how this particular system is wired. My converter/charger is a B-W Manufacturing Inc model 3240. I have handy Bill & Jean Moeller's "RV Electrical Systems, A Basic Guide to Troubleshooting, Repair, and Improvement", and they state that in Linear Unregulated Converters "a common feature in many units is a transfer switch which automatically disconnects the battery circuit from the RV's main house circuits whenever the shore power cable is plugged in"

Would this be the case with MY converter? Is my bank of 3 batteries completely taken out of the power line circuitry when I am "plugged in"? Is the "charging" portion of this converter/charger a whole separate circuit? This might explain why I get no fluctuations in voltage with meter directly connected to battery terminals when I turn things on in that circuit, but DO get the fluctuations at the fan connection itself?

A link to the converter's 3 page "manual" is located HERE:

http://www.parallaxpower.com/3200/Parallax%203200%20Series%20Owner%20Operator%20Manual.pdf

Any help in clearing up this particular puzzle will be appreciated as usual. Thanks again!

It appears from the "manual" that the 3240 would have the transfer switch. It implies that only the 3215 has the manual switch on the box. The charger circuit should remain online to charge the batteries, even though they are not supplying any power to the house.

You may well see a voltage drop at the fan terminals when it is turned on but the system voltage should stay pretty much constant.

Gary,
  Once again, thanks. That's what I thought I was reading in regards to the converter, but I appreciate the extra set of eyes and extra brain cells to confirm. 

So, since that is the case, is it now "normal" so see that much of a voltage drop, down to 10V, when both fans and 2 light fixtures are on? This still does not seem like an ideal situation to me. Do normal working converters not at least attempt to provide 12V down the lines when things are turned on?
I hope that question is clear, since I am not an electrician I don't know the correctly teminology of what I am trying to ask.
It would just seem to me that a good piece of equipment could act like a pressure regulator, and keep a constant pressure (in this case voltage) to EVERYTHING on a particular line.

Or is it just the AMPERAGE that is important in this equation? (which I haven't measured yet)

Do newer converter/chargers do this?

So I am back to looking at new converters. Parallax obviously recommends their own models in the 7400 series, and strongly recommends NOT to go as high as the 7465 on a 30amp input service on the RV, so the Progressive Dynamics 9180 that John recommended earlier would not seem to be a good idea.
The upgrade PDF is here:
http://www.parallaxpower.com/3200/3200%20Linear%20series%20replacement.pdf

Amazon sells their recommended upgrade here (they also have a 7445):
http://www.amazon.com/Parallax-Power-7440-Electronic-Converter/dp/B003DJKJ1U/ref=sr_1_2?s=automotive&ie=UTF8&qid=1346303534&sr=1-2&keywords=Parallax+Power+Supply++7400

or there are the Progressive Dynamics choices, the 9245 here:
http://www.amazon.com/Progressive-Dynamics-PD9245CV-Inteli-Power-Converter/dp/B000GANZZ6/ref=pd_sim_sbs_auto_2

I would prefer not not have to swap out wiring, as the converter/charger, transfer switch and fuse panels are on the opposite side and at least 15 feet rear of the RV from the genset and battery bank. And if the 30amp service limitation is an issue anyway.......

So, given those parameters, what new converter/charger is my best choice? Just buy the quick look, it would seem that the Progressive one would dissipate heat more efficiently? Can I go the extra 5 amps without swapping wires?

So, since that is the case, is it now "normal" so see that much of a voltage drop, down to 10V, when both fans and 2 light fixtures are on?

Click to expand...

No, because the devices should not be affecting each other. You can get a voltage drop at the device, but the wiring is in parallel (or should be, anyway), so each device should be receiving the same voltage (system voltage). If the system voltage drops under a modest amp load, then the converter could well be defective. I worry, though, that there could be some other factor you haven't yet discovered, e.g. a corroded connection somewhere. A bad connection will often test ok for voltage but it quickly degrades when the amp load increases. That could produce your symptoms too

This is probably far-fetched, but the behavior you describe sounds almost as if the fans and lights are wired in series rather than parallel. Could someone have done that? Or maybe mistakenly swapped a wire or two around when making some other change?

Can you bypass the existing wiring and temporarily run some clean wire straight to the two fans from the converter?  And see if the behavior is the same as before?  Also, what happens when on battery only (converter is inactive)? Do you get the same voltage drop from a fully charged battery? Either of these would suggest a wiring problem rather than the converter itself.

Gary,
  Unfortunately I didn't get to test the fans on just battery power today. Hopefully tomorrow afternoon or Saturday.
Unless the wires were inadvertently wired in serial from the factory I don't think that'll end up being the problem. Even though the RV is old (it's an '87), it only had 37K miles on it when I bought it a year ago. Most of the problems that it had seemed to be from DISUSE or poor storage maintenance rather than overuse. I purchased it from the second owner (who was really just an auto dealer), and it doesn't look like the original owner did any upgrades or repairs himself. The fans that I replaced sure looked like originals and the light fixtures were not swapped.

So I really doubt that the the wires were screwed up by him.
I am also beginning to wonder if the problem could possibly lie in the outlet that the RV is plugged into? How much of a "draw" does the converter have? The RV is plugged into an outdoor yard pedestal that also has a pool filter occasionally run on the same circuit (it has a 20amp breaker).

See, the problem here was that I just assumed that because a previous poster said that the DC is filtered by the batteries, that the circuit was wired thusly:

120V plug-----> Converter/charger---->Battery Bank--------> 12V fixtures,etc.

and not that this converter "disconnected" the batteries while on shore power.

Is it possible that the 120V in (and thus the converter) is short on power (either volts OR amps) and THAT is causing the problems?

Is it possible that the 120V in (and thus the converter) is short on power (either volts OR amps) and THAT is causing the problems?

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It is [barely] conceivable but a very remote possibility. It only takes 1 amp @ 120v to produce 10A @ 12v, so the converter power draw from shore power is quite low. Assuming the 3240 is a max 40A converter, that's less than 4 amps @ 120v for max DC output, and rarely would you ever reach the max.

Gary,
  Thanks again. I didn't think that the converter itself had much of a power draw. I managed to get the test done on just battery power and had that same weird voltage drop.

It's too bad that I already disposed of the old fans or I would try the test with one of those connected. Like I said, I can't imagine that the RV was mis-wired from the factory. There is no evidence that anything through that part of the ceiling was worked on previously. (The original owner kept pretty meticulous records of anything he bought for the RV or got repaired, for example I know there was a problem with the original genset) and the guy I bought it from really only purchased it to resell it. I think at most he swapped in new batteries.

I'm just going to buy the new converter, but need to know, since the old one is only 40 amps, am I safe with the Progressive Dynamics 9245 or should I stick with the 9240? Is there a better brand? I don't want to "cheap out" on this crucial part.

Thanks again!

I'm just going to buy the new converter, but need to know, since the old one is only 40 amps, am I safe with the Progressive Dynamics 9245 or should I stick with the 9240? Is there a better brand? I don't want to "cheap out" on this crucial part.

Click to expand...

It won't make much difference, one way or the other!!. Just stay with the 9200 series as it has the built-in charge wizards (as opposed to the 9100 series in which the wizards are purchased separately and plugged in.

Anything in the 40-50 amp range will be fine. And do get the 9200 or a similar model that has the three stage charger. PD is a pretty good brand - they have been around a long time and will likely still be there if you need them.