Wiring Question: breaker box and converter

Matt_Lewis · 08-12-2019, 10:40 AM

I have a 2018 36BHQ and always seem to have weird issues around electrical especially when the batteries get really low. This usually happens after we forget to turn off the inverter which powers the fridge while driving down the road.

Questions:
1. If the inverter was left on while on shore power, would the converter be powerful enough to keep the batteries charged faster than the inverter could drain them?

2. When the batteries are completed dead(less than 10v) and we are plugged into shore power, would the converter breaker trip turning off all power to everything?

We have the WFCO WF8930/50 breaker box and the WFCO 9855 converter.

I would be interested how others use their inverter with batteries and when they turn things off and on etc. Maybe our process is wrong.

Also, we just had to replace the deep cell interstate batteries because they weren't holding a charge any more. They were both less than 2 years old.
thanks
matt

5picker · 08-12-2019, 10:57 AM

I suspect your issues were related to bad batteries.

Now... you're going to get a tirade of posts telling you your WFCO converter is junk and get rid of it as fast as possible.

I'm not going to say you don't have a converter issue not keeping your battery(ies) charged but please check it first before just replacing it. There are thousands of WFCO converters out there doing an OK job.

Check your converter output with a meter and determine the states of charging.

Also... do not let your batteries deplete to 10v. That has likely contributed to having to replace them more so than the converter. Yes, it is possible a current load of trying to charge a 10v battery(ies) could trip the breaker or blow the protection fuses.

Does YOUR inverter auto-switch to 120v pass-through when plugged in?
Most I've seen do, some do not. No real need to turn them off if they auto-switch.

clr · 08-12-2019, 11:03 AM

Question 1 answer: When you plug into shore power the inverter will normally switch to AC and not draw from the battery. When on shore power I turn off the inverter, but if I forget it will not draw down the battery.

Question 2 answer:You should never drain the battery to 10V. That is a stone dead battery at 10V and more than 90% discharged. You should never discharge a 12V battery to more than 50% or about 12V or permanent damage will be done. If you got 2 years usage out of batteries that where treated in this manner, you are very lucky. Your remaining capacity of the batteries now will be nil. The converter will not normally trip the breaker when applying full charge to the batteries. But given the current state of the batteries this may happen.

Your tv should be providing 12v to the batteries when you are on the road. I run my residential fridge when on the road all day and the battery discharges very little. My discharge is due to pit stops we make for lunch and such. I would make sure your TV is providing 12v to the battery while towing.

Matt_Lewis · 08-12-2019, 02:12 PM

@5picker my inverter setup is a bit different than I am used to and I haven't figured out exactly how each setting works but basically the inverter itself has a off and on switch in the front of it and then in the coach I have a manual on/off switch for it. the most recent issue occurred when we left the manual switch flipped on for more than 24 hours, while we were plugged into shore power.

what would the converter output be and how could I test different stages?

@clr the truck charges the batteries but with the poor state of the batteries I think the truck really only kept the inverter powered for the fridge to stay running.

Thank you guys for a quick reply!
matt

Matt_Lewis · 08-12-2019, 02:27 PM

Attempting to troubleshoot all my issues for anything obvious, I traced wires per the wiring diagram on the breaker box and I found that per the breaker box, the factory switched the 2 black negatives coming into the box from the battery and the converter.

So essentially the black and the white one at the top of the first picture should be switched...would this be the cause of my strange battery draining. Can I just flip them now?

At the risk of asking too many questions at once...when the converter breaker trips sometimes it doesn't reset right away and my wife reported smoke smell coming from behind the breaker box when attempting to reset the break and it tripped instantly. On our last trip when everything broke and I had to buy new batteries just to get home what triggered everything was when I went to use the front jacks, I immediately got a jack fault and the converter breaker tripped. When the converter breaker trips, I lose all power to shore power things like AC microwave tv etc AND the battery items all go really dim because they are running on the drained battery.

Thanks again for the help!
matt

5picker · 08-12-2019, 02:30 PM

Quote:

Originally Posted by Matt_Lewis

@5picker my inverter setup is a bit different than I am used to and I haven't figured out exactly how each setting works but basically the inverter itself has a off and on switch in the front of it and then in the coach I have a manual on/off switch for it. the most recent issue occurred when we left the manual switch flipped on for more than 24 hours, while we were plugged into shore power.

what would the converter output be and how could I test different stages?

@clr the truck charges the batteries but with the poor state of the batteries I think the truck really only kept the inverter powered for the fridge to stay running.

Thank you guys for a quick reply!
matt

Here's the specs directly from the WFCO web site. There is a wealth of information there... WFCO

"Automatic three-stage charging extends the life of your battery with output voltage modes of 13.2 VDC range “float” mode, 13.6 VDC range “absorption” mode, and a 14.4 VDC range “bulk” charge mode."

clr · 08-12-2019, 02:32 PM

OK I am confused now, some what of a normal state some people say. An Inverter takes 12vdc and outputs 120vac for use when you do not have ac voltage available such as on the road.
A converter takes 120vac and outputs 12vdc for charging the batteries and for use within the unit. The converter output depends upon the model and type of converter you have and the number of steps or charging level that that model is capable of producing. A three stage charger has a bulk mode about 13.2 vdc, and absorption mode and a float stage 13.2 - 13.4 vdc.

clr · 08-12-2019, 02:41 PM

I would NOT recommend that you swap the red and white cables at the top of your picture. They look normal to me. The red is normal Positive + and the white is Normal Negative -, the negative is connected to the frame ground within your unit. Short miswiring within the box is not your problem I believe.
If any thing I would start looking at the battery connections and make sure the red lead is connected to + and the white is connected to -. This is where people normally screw up. If this was done you have blown the 40 amp fuses in the converter for both the positive and negative side. That is the normal mode of failure.

Matt_Lewis · 08-12-2019, 05:36 PM

Thanks again!

My idea was to swap the black wires. So the negative from the battery and the negative from the converter. So if you follow the jumper it leads to the white.

I called WFCO tech support and they suggested not doing that and mentioned something to do with the negative coming from the converter was polarized. I am not and electrician so I have no idea what that means, I just could easily see how a line worker could grab a black wire thinking it was something it wasn’t and as long as batteries are at full charge there are no issues.

Just a guess though.

rlh1957 · 08-13-2019, 01:38 PM

I wouldn't recommend starting to swap and reverse cables. Black is Hot in AC and Black is Negative/Ground in DC. Swap those and a new world of problems will begin.
Red is Positive in DC. Without a voltage and amp meter don't just rely on a printed diagram for your total guide... nor always put your faith in a color being what it should normally be. Many a problem or mistake have come from doing it the normal way.

Matt_Lewis · 08-13-2019, 04:14 PM

@rlh1957 I agree on the colors for sure, but I traced it back to the battery and then back to the converter so I know for certain that those blacks are swapped based on the diagram but I am still gun shy on flipping them because everything is "working"...at least until the batteries die then really bad things happen along with smoke!

Chuck_S · 08-13-2019, 04:47 PM

In an automobile Red is positive. But trailers are "houses" and follow house DC wiring schemes. Sometimes. Best way is to find the wire from your battery box to the trailer frame. Should be (and mine is) White. That's the ground or Negative wire. The other wire should be Black -- but don't be surprised if it's Red. Again, find the ground, that's the Negative 12vDC wire and the Positive will be the "other color."

Unless you disconnect the battery from the trailer in storage it will be severely deep discharged in less than a month from things like the LP detector and radio memory. 10vDC is damage range. Battery is essentially dead, won't power much, at 11.6v, just 1v lower than full charge. If you don't have a battery disconnect switch it's easy to wire one thru a marine (boat) battery switch and mount it on the outside of the battery box. To completely disconnect switch the Negative/Ground wire. Should only be one wire there vs several at the Positive terminal.

-- Chuck

valleyduo · 08-13-2019, 05:32 PM

When on shore power, your converter breaker tripping should not cause your air conditioner and microwave not to work. Either your main breaker or the pedestal breaker would cause both to go out. The dimming of the lights would be due to voltage drop from the breaker tripping. As was stated the converter will feed the batteries 13.2 volts or so when that breaker trips your back down to 12.6 or whatever the charge level of the batteries are. Have you checked the voltage at your batteries while the converter is working to verify proper charge? Also put eyes on the converter itself. The smell of smoke or burning may indicate a problem with the converter as well. Now you inverter, ours is set up that the switch (button)on the inverter should be off and then it can be operated remotely by the rocker switch. If the switch on the inverter is on, that overrides the rocker switch and the inverter will just stay on. That's how ours works anyway.

Matt_Lewis · 08-14-2019, 06:48 AM

@valleyduo I have put eyes(and hands) on the converter when I was tracing all the wiring per the diagram. This is how I know, at least per the diagram, the black negative and the converter negative coming into the breaker box are flipped. It is in the wall behind the breaker box mounted to the floor. It gets rather hot and sometimes the internal fan will kick on.

Thanks for the info on the inverter. When plugged to shorepower should I complete turn off the inverter or is leaving it in the remote mode fine for extended periods of time? It too has an internal fan that can get pretty noisy.

@Chuck_S I do have a battery disconnect for the internals on the RV but the inverter is hard wired around the disconnect switch so it can stay on but I check all that before and make sure it is off.

I am afraid that the blacks are switched and when the batteries are good and new they can take the abuse of the blacks being switched but that eventually wears the batteries down and then nothing works and all the craziness with the breaker tripping and then shutting everything like ACs microwave, TV, etc off.
Thanks!
matt

valleyduo · 08-14-2019, 07:51 AM

Leaving the inverter on is generally a point of preference. We generally turn ours off once connected to shore power, but if we are going to be out for most of a day, we'll turn it on so the fridge will have battery back up in case of an outage. Once connected to shore power the inverter switches to standby mode so it shouldn't have much interference with charging batteries.

tomkatb · 08-14-2019, 08:21 AM

How many batteries do you have?

Rating of bank in amps?

Size of residential fridge?

I wonder if it is simply not enough battery causing issues.

I am sure the batteries are damaged.

clr · 08-14-2019, 08:30 AM

Matt (op)

If you look very carefully at your wiring diagram you will see a jumper another wire connecting the two neutral points. You are correct that the battery neutral cable should be to the top, this is only to ensure that the vault lights associated with the fuses will always have a path back to neutral ( to allow the light to light when a fuse blows). If that jumper wire is in place and it looks to be from your picture, both the neutral cables are at the same point electrically and you do not have a problem.

Matt_Lewis · 08-14-2019, 08:48 AM

@tomkatb we have 2 deep cell batteries. previously they were interstates and I replaced them because they were toast with a generic brand because I was stuck at the campground with no power or batteries and the circuit breaker for the converter kept tripping and I couldn't turn on anything inside or slide the slides in or bring up the jacks. The new ones are holding and have been for about 2 months at 13.8. Since the new batteries we haven't had any issues with tripping breakers but the batteries haven't died yet either.

The fridge is the HiSense one from the factory as an "upgrade"...I don't know the specifics on it.

@clr thank you! that is what I was thinking too. so even though it is wrong, it didn't matter.

tomkatb · 08-14-2019, 10:04 AM

My opinion.

That is a big fiver. A big refrigerator.

You stated something about the battery as 13.8. That is a weird number.

Two inexpensive lord knows what kind of batteries is not a good plan with a residential fridge. You need four good ones. Or, always plug in.

Likely there is a low efficiency inverter and poor batteries and no way to monitor I assume.

These batteries should fail to run the fridge a lot over 8 hours. Good day, low temps, longer. The tv charging will do little. There are also lots of parasitic loads that use the battery up.

What I would do is purchase a BM2 battery monitor. About $40 on Amazon. Installs in 5 minutes. Transmits a voltage to your phone and keeps a graph.

A fully charged battery bank is about 12.6 volts. There is a thing called surface charge. After charging a battery will read higher than 12.6 for a while. Never let the battery get below 12.1.

After owning the battery monitor you will learn about your converter and batteries. The graph is essential. It takes days to recharge a low battery 100%

In a few weeks you will get an idea I think about what is going on.

Do not change wires.

I think you are learning about batteries the hard way. They are not good ways to store power. One of two Achilles heals in the green energy plan.

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