Converter / Charger Question

[Thermoguy]

After using our 5th wheel this weekend I have a question – do I have a bad Converter / Charger?

A couple times over the weekend, especially in the morning, having space heaters running, the lights would get very dim then the CO alarm would sound. If I turned off the heaters, the alarm would stop and the lights would come back up. Kind of a low power issue. After unplugging from shore power and hooking up the truck, I tried to run the water pump and realized I had no 12v power. However, my slide and jack power still works. Just no lights, pump, or fridge. After getting home I am checking things out. I have 12.75v at the 6v batteries in series not plugged in to shore power. After plugging in and waiting a little, I had over 13v at the inverter leads and over 13v at the batteries. No DC power when not plugged in to shore – everything works when plugged in, however, if I try to use too many items, my power gets low. I checked and have only 6-7v at the DC leads when plugged in and AC running like a space heater.

I do not know what inverter I have or how to replace – or if I can replace with something of higher quality. My 5th wheel is a 2006 Forest River Sierra.

Here is a couple pictures – thanks for any help you can give me.

[wa8yxm]

You are losing 120vac it's dropping to a lower voltage due to the load of the space heaters.

Now the question is this a park side or an RV side issue?
On converter of the type I ***THINK*** you have the converter is normally connected (120 side) to one of those breakers directly No daisy chained devices
But if the actual converter is ... other than behind the fuse/breaker panels then it may be at the end of a Dasiy chain of outlets.

RV wiring is not really up to 1500 watt loads in my expierencem the Uni-box/Quick-Box outlets (Self contained) do not have enough contact area with the wires so they overheat and voltage is lost.

The CO alarm may have been responding to low voltage
or to vapor given off by overheated wireing (I've smelled that aroma when using space heaters)

I ended up installing special curcuits for my space heaters 12 ga wire and 15/20 amp outlets. but on your 30 amp rig that might not be possible

[Thermoguy]

Thank you for the help.

In searching for those 12v breakers, which are behind my battery, I found this bad connection. Also found the negative side is about the same, can pull the wire right out. Need to get a new connector then I can fix it.



I'm still not sure what is causing my low power when on shore power. I will have to spend more time with that. But, for now hopefully my 12v power issue is solved - thanks for the help.

[ndrorder]

About all you can do is follow the +ve cable from the batts.

Here is a ling to an auto resetting RV 12V breaker. A manual reset looks the same except a little button will pop out of its side when it trips. Push the button back in to reset.

https://www.amazon.com/RKURCK-Circuit-Automatic-Automotive-Protective/dp/B07LBNFZGK/ref=sr_1_9?dchild=1&keywords=rv+breaker&qid=1620771193&sr=8-9

[Thermoguy]

Thank you for the comments - about the other fuse - I'm searching high and low, no clue. Any suggestions where that might be?

[Sandia_Man]

There is a fuse around the battery or between the converter and battery that may have blown. Slide motors and power jacks are wired directly to the battery bank which is why they will work without shorepower. It never hurts to upgrade your stock converter, particularly if you do lots of RVing off the power grid and need quicker recharging of battery bank, multiphase charging keeps batteries much happier and often increases their longevity.

[ndrorder]

Check for a fuse, circuit breaker, or a self resetting circuit breaker between the batteries and the fuse panel in the second picture. If it tripped/blown, it is likely there will be no pump, lights, or fridge. Slide and jacks work because they will be direct connected to the batteries due to their high draw. All 12V works when plugged in because converter is providing the power it just may not be getting to the batteries. So, measure voltage across the thick red and white wires in the second picture and across the +ve and -ve of the batteries when plugged in. They should be the same and at least 13.3VDC. If less, there may be converter issues.

Electric space heaters and the AC are 120V appliances. If too many are used or additional extension cords are added to the shore line, the voltage in the circuit will drop resulting in low power and possible equipment damage. I'm surprised you could run more than one 1500W heater without tripping the breaker at the pedestal which makes me think the inverter or load sharing was somehow in play. If the inverter was in play, the converter was trying to keep up delivering 12V to the batteries which could have tripped/blown the above mentioned 12V safety devices. If the converter was trying to keep up while multiple space heaters were running, the 120V system was surely overloaded and voltage low.

Check for fuse/breaker/self resetting breaker in 12V cables.

Verify at least 105V in the AC circuit when running things like heaters and the A/C or equipment may be damaged.

Verify voltage out of the converter and at the batteries is the same and more than 13.3V.

Worry about the inverter later.

[Thermoguy]

dougrainer wrote:
1. You do not have an Inverter
2. You have a CONVERTER which is what is in the Pic you posted.
3. Space Heaters are 120 volt, so ANY 12 volt problem will not cause 120 Heaters to malfunction. If the battery 12 volt system is DEAD, your 120 heaters will still work
4. ALL a 12 volt Converter does is take 120 volts ac and converts to 12 volt DC and also sends a charge to your coach batteries
5. Your battery NOT connected to shore power fully charged and after sitting for 1 hour should have a 12.6 or higher voltage with nothing ON in the RV. If you do not have that voltage your batteries are probably bad and need tested.
6. With batteries at 13.0 volts you stated you do NOT have 12 volts in the RV not connected to shore power? If so, that points to a tripped 12 volt circuit Breaker or fuse, BUT, if so, the Converter would not be charging the batteries. Doug

Thanks Doug - appreciate the correction.

I do not have a battery problem, batteries stay charged and do not discharge if sitting not on charger. Also, before my trip I ran off DC power for a couple days without any loss of battery power, new batteries this past August. I have checked all my fuses and all good. Could there be a fuse not shown in the picture? I can not find fuses anywhere else.

[dougrainer]

1. You do not have an Inverter
2. You have a CONVERTER which is what is in the Pic you posted.
3. Space Heaters are 120 volt, so ANY 12 volt problem will not cause 120 Heaters to malfunction. If the battery 12 volt system is DEAD, your 120 heaters will still work
4. ALL a 12 volt Converter does is take 120 volts ac and converts to 12 volt DC and also sends a charge to your coach batteries
5. Your battery NOT connected to shore power fully charged and after sitting for 1 hour should have a 12.6 or higher voltage with nothing ON in the RV. If you do not have that voltage your batteries are probably bad and need tested.
6. With batteries at 13.0 volts you stated you do NOT have 12 volts in the RV not connected to shore power? If so, that points to a tripped 12 volt circuit Breaker or fuse, BUT, if so, the Converter would not be charging the batteries. Doug