I have installed some solar on my 179 and am getting some feedback I believe through the 12 volt side (lights, refrig controller, speakers, thermostat, and charge controller).  I have shut the WFCO breaker off going to the built-in converter.  I have installed a Zantrex converter, charger, and switcher (one unit).  

My question is: is someone familiar with how the polarity circuit works and is it just working in conjunction with the WFCO converter.  

My plans are to disconnect the wiring to the WFCO converter (not just simply turn off the breaker) and to disconnect the wiring to the polarity circuit.

Scratching my head,

Jay 

Thanks offgrid but I am still confused even with your answer...I have a Xantrex 817-2080 it's a freedom XC 2000 that's 2000 watts continuous power and 4000 watts surge and it's true sine wave / the charge controller is a Morning Star ProStar MPPT-40M which has capabilities of handling 12/24 volts with a rated load rating of 30a and max. battery charging current of 40a also I have a tri-metric TM2025 RV battery monitor tied into the system.

The installation was to pull the shore power from the breaker box going to the WFCO converter and run a new 120v 12/3 wiring to the Xantrex located under the bed in a new compartment I made next to the water heater.  From the Xantrex I ran new 120v 12/3 wiring to the 120v breakers in the breaker box. The Xantrex is also hooked up to the batteries with 0-2 wire.  I have 4/100 watt panels mounted on the roof 2 wired in series and then 2 pairs @ 24 volts wired to the charge controller.  In addition I have 2/100 watt portable panels wired in series that can be plugged into the system @ 24 volts.  The peak amperage output of the panels are a little over 5 amps per panel so I will never be limited out going to the charge controller.  Due to weight restrictions I have limited my batteries which are outside on the tongue of the 179 to 2 deep cycle 12v batteries, I realize that this is the weakest link in my system.

On the 12v side all panels are routed to the charge controller and there are battery leads (+/-) going from the charge controller to batteries and all the 12v power to the house electrical needs goes through the load terminals of the charge controller.  This power is through 8 gauge wire (both + and - and that's through wire not a frame ground for the -) from the charge controller to the breaker box 12v side.

As I have indicated to disable the WFCO converter I shut off the 120 breaker in the breaker box leading to the WFCO converter and I have done nothing to reverse polarity fuse/system.

The problem that I am encountering is that when the batteries are reaching the current set point for going to absorption from bulk charging @ currently 14.4 (from 14.7) volts the 12v lighting starts turning off and on (when in on switch position), the refrigerator powers up and down when in the any of the running positions, the thermostat turns off and on when in the running or off position, the radio is powering up and down on matter whether it is on or off.  The TV is unaffected as nearly as I can tell.  When the radio is powering up and down there is a cackling sound coming over both speakers.  Reviewing the charge controller over an computer connection it shows radical swings in voltage and amperage reading of about 5 points each.  We have been experiencing these symptoms and we're trying to iron this out.  Have been working with the techs at Morning Star.  What I have tried to elevate these issues are first reset the high voltage cut off from 15.4 to 15.1 which didn't correct the problem, then ran a chassis ground from the charge controller to the Xantrax then to the frame of the pod which didn't correct the problems, then ran a dedicated negative load line from the charge controller to the breaker box (rather than using a chassis frame negative) which has not resolved my problems.

What I am planning on doing now to resolve these issues first physically disconnect the WFCO converter + and -, then physically disconnect the polarity circuit.  I want to make sure that physically disconnecting the converter and polarity circuit will not do any harm to the system that I am using.

If this doesn't work I guess the only other option is to replace the charge controller because I believe the charge controller is not ramping to a lower current going from bulk to absorption and then to the float mode.

Any help would be apricated,

Jay    

So, I assume that you're using the Prostar to feed the 12V buss so you can use its LVD feature to protect your batteries? Where are you connecting the Prostar load output to the 12V buss?

I don't think you have any need for the reverse polarity function of the WFCO if you've connected everything with the proper polarity. Those are only there so they blow in case someone connects the battery backwards. The fuses are making connection between the WFCO charger and the 12V buss. The terminal labelled Vcc+ is where the WFCO charger +12V feeds into the buss. As you are suggesting, this connection can be removed as you will no longer be using the WFCO charger. The Xantrex will be doing your shore battery charging instead. Pulling the 40A fuse should do that, but you can confirm with a multimeter, or remove the wire from that terminal as well. 

If isolating the WFCO doesn't resolve your problem then next I would try bypassing the LVD function of the Morningstar. It seems like this is most likely what is causing the cycling off of your 12V loads. You can connect the battery directly to the 12V buss as it was originally (except with the WFCO charger disconnected) and see if that resolves the problem. its possible you might just have too much charge and discharge current going in and out of a small battery bank, causing cyclic behavior as the Morningstar is trying to operate both is overcharge and undercharge protection features.  If that fixes your problem then you can run the system like that for awhile and monitor the battery low charge condition manually, and start planning for that big Lithium battery capacity upgrade. 

Good luck and keep us posted on how it goes. 

Thanks offfgrid that makes sense to me and I will try eliminating the polarity circuit first and disconnecting the WFCO controller.  As far as the +12feed from the load side of the controller, I can't remember now I'll have to check that out, I am assuming the 12v buss in the breaker box???  And yes I am using the LVD on the Prostar.  I will let you know what I find.

Are the batteries in good shape? Sounds as if when the incoming charge current is reduced, and the loads are all on the batteries, the battery voltage is falling flat. 

Then the controller ramps up and begins charging again. Then it falls into a 'loop'.....

Using a digital meter, probe across your battery terminals when the problem occurs, see if the batteries are 'failing' in between charge cycles. 

Also, see if all of your anticipated loads, or only a few of them, will operate properly from the batteries with no solar input at all, such as at night.

Thanks podwerkz for another thought, the batteries are less than a year old but that doesn't mean their good and I haven't checked them....something more on my to do list but I am still thinking that it is something internal to the system that I have not accounted for.  Just have to find it.

Offgrid I did call the techs at WFCO and they told me that if the 40a polarity fuse is taken out (or blown) then non of the 12v system off the circuit board will function (like the lights or radio), thus saying that the polarity fuse is plugged into the circuit board and can't be disabled.  Well before I got digging into the breaker box I removed the polarity fuse and all the 12v system that could be easily checked worked???  So I have removed the polarity fuse and physically disconnected the WFCO converter from the breaker box wiring.  As to the wiring of the +12v coming from the charge controller it goes to a 30a breaker located behind the breaker box and is joined on the same side of the breaker with a lead going to the 12v buss in the breaker box circuit board and the other side of the 30a breaker is routed off under the floor to the other side of the trailer and I am assuming that is the hot lead for the slide out motors.

Now I am waiting to get some sunshine and try to replicate the problems.  I may have located and resolved my issues (hopefully) but still get to check out the batteries as podwerkz has suggested.

Thanks to all

Hi offgrid,

Sorry to be so confusing but not being an electrician I can get some terminology messed up.  But what I am trying to say is that in the  original wiring there was a orange wire maybe 10 gauge coming out of the back of the 12v side of the breaker box and that orange wire hooked up to one poll of an inline circuit breaker (maybe 30a) which was screwed to the floor behind the breaker box. Attached to the same poll of the inline breaker was a 8 gauge red wire running to the batteries up on the front of the trailer.  Connected to the other poll of the inline breaker (in other words being protected by the breaker) an orange wire ran under the flooring and over to the slide-out side of the trailer and I can't remember where the power ran to.  I was thinking that the orange wiring running under the flooring was for the slide-out motors but I am wrong because the slide-out has it's own dedicated circuit and is fused in the breaker box.  So I will have to do some more digging.

What I did when originally wiring the charge controller I used the + from the load of the charge controller to the 12v side of the breaker box, I disconnected the red + 8 gauge wire connecting the batteries to the 30a inline circuit breaker screwed to the floor behind the breaker box, then I used this wire to run the + from the charge controller to the 12v side of the breaker box.  The - wire was 8 gauge black wire connecting a 12v buss bar screwed to the floor behind the breaker box to the chassis frame back by the wheel and then on the front of the trailer from the frame to the - side of the batteries.  I originally disconnected this black wire from the batteries and use it for my - form the charge controller.  I have recently changed this wiring to run a black 8 gauge wire from the - charge controller to the - 12v buss bar screwed into the flooring behind the breaker box.

Currently the + from the charge controller which is an 8 gauge red wire connecting to the 30a (I believe) inline automotive style circuit breaker going to one side of the inline circuit breaker and from the same poll 10 gauge (I believe) routed to the 12v side of the breaker box.  The other poll on the inline circuit breaker screwed to the floor has a single wire running under the flooring to the other side of the trailer and I think that is a 10 gauge orange wire.

Also there is only one fuse on the circuit board controlling the reverse polarity system, not 2 fuses.  With that fuse removed and the reverse polarity system disabled the 12v lights and radio are still working (that's all I checked).

I will have to do some more digging to find out exactly where the orange wire that joined on the same poll of the inline breaker as the + 12v red wire from the charge controller is connected to.  My current thought is that it is connected to the circuit board.  I also will be discovering where the lone orange wire on the opposite poll of the inline breaker is routed to (the orange wire on the protected side of the inline breaker).

Hope this clears up some muddy waters.

That orange wire should be the supply wire for the refrigerator 12v element. 

Remove the lower fridge vent outside and you will see it.

Mine has a 15a self-resetting breaker, and if it is overloaded, it will cycle on and off repeatedly until the overload is cleared. You will hear it clicking if it is doing this.

Yours might be 30a if it also supplies something else such as the slide motor.

Thx Podwerkz you are correct I didn't check the size of my inline breaker, it could be a 15a inline circuit breaker and yes the orange wire does show up at the refrigerator for 12v power.  

As a follow up to the problem I was having I called WFCO before I pulled the 40a reverse polarity fuse, didn't want to damage the circuit board, and found out when I told the service tech (seemed like a good one) that even though I had turned off the breaker and removed the 40a polarity fuse I was still getting power into my 12v trailer system.  The tech told me yesterday that removing the 40a fuse will do no damage to the circuit board but it will eliminate power to the 12v side from the built in converter on the WFCO breaker box.  Further more supplying power to the circuit board from another converter, like in my case, if you have removed the 40a fuse you will be powering the circuit board from another source anyway and the reverse polarity system will be non functional.  The reverse polarity system is wired between WFCO's converter and the circuit board via the circuit board.  This last statement is via my understanding only, not from WFCO.

The good news is I have been testing the system for the last 2 sunny days after having physically disconnected the WFCO converter at the 120v breaker and removing the 40a reverse polarity fuse, and the system has cycled through 2 complete cycles of bulk charging to absorption charging to float charging and I have been unaware of any feed back light flickering, crackling of the speakers, radio turning off and on, or any other abnormal behavior.  The charge controller seems to be limiting the charging amperage, which is suppose to be doing all along.  I am going to be checking the behavior of my system for a few days before I declare this situation resolved.

Thank you very much offgrid and podwerkz for all your insightful wisdom.  I couldn't have figured this out by myself.

 

offgrid I think I know the answer to this question before I ask it but here goes, is there a way to know the available amperage available from the solar array at any given time?  My understanding is that the solar array amperage, that in my case is being measured by a trimetrics battery monitor or by the Prostar charge controller is just the current (amperage) that is being processed (used) not what is available at the time in the array. 

Is my thinking way off?  Or is there a way to measure the available array amperage? 

The solar array is inherently current-limiting; if you short the leads on a solar panel, it will just happily provide as many amps as it is capable of. If there's not a lot of sun, not too many amps. If the sun is full on, then it will be close to the maximum it can provide.

Yes there is: Disconnect the panels from the controller and, using an amp meter or DMM with a high enough amp setting, and short the panel connectors thru the amp meter.

You can short a 100 watt panel and see about 5-6 amps in full sun. Two panels in parallel will double the amperage. Two panels in series will double the voltage but the amps will remain about the same.

Each solar panel should have an Isc rating, which is, essentially, 'amps, when short circuited'.

A panel can actually over-produce if a few specific conditions are present, but usually they under-produce. 

Your controller should show actual amperage coming from the panels, which as you know will vary with loads and battery state of charge.

Offgrid in your 4:30 post you mention to measure the voltage and current on the solar side of the controller then measure the voltage and current on the battery side of the controller and multiply the voltage and current to convert the readings to wattage on the solar side and then the battery side of the controller.  I get that and then do the math and find out the controller's efficiency and that's understood but obtaining the voltage and current measurement on either side of the charge controller what would be the best way to get that accomplished.  Keeping in mind that I have a computer inter-face with the Morningstar and via that inter-face all that information is available on the readout but it's coming from the charge controller and if that is not working properly would those readings be accurate?

I guess this is just getting a little too far out, so that I can say, just look at all the power the solar array is receiving now and have a warm and fuzzy feeling all over.

Thank you for all the insightful information offgrid which has helped me a lot and to determine / resolve what I will call a cyclical negative feed back issue effecting the charge controller's performance.  Removing the 40a reverse polarity fuse on the circuit board has seemed to resolve the issue.  At least I haven't experienced the issue in the last 3 days and your right the Morningstar is a good piece of equipment and they have fantastic service techs, who are very helpful.  My thoughts are that the charge controller has always been doing its job and was just getting sketchy inputs from the WFCO circuit board via the reverse polarity circuit.  Time will let me know if I was wrong.

As to the amperage at the solar array, this is just curiosity on my part and if there was a simple meter (or something) that would be great but as I said I didn't think its possible.  I know there are ways of measuring the current if you disconnect the panels from the system but in reality it's just not that important.

Again thank you for all for the helpful insights.