Did our converter die?

FrankMor · 02-20-2016, 10:34 AM

We had something strange happen this Thursday while camped at Lake Murray State Park in Oklahoma. We were in the trailer, 2015 Coachman Freedom Express 248RBS, when the lights dimmed then went back bright. When this happened, the fan on the converter started, and the kept running for hours. I turned the main breaker (50 amp) off and back on, the fan came back on. I turned the converter breaker off then back on and the fan came back on. I tuned the converter of for the rest of the day. Turned the converter on during the night (2 am) since the heat was on and not wanting to run the battery down, it is an Interstate 27 marine. The fan ran till we disconnected to come home Friday. The refrigerator and WH were on electric. Did the converter, a WFCO 893050, die or did it lock on high output? I have not plugged in in at home yet, wanted information first.

FrankMor · 02-20-2016, 04:31 PM

I plugged the TT in this afternoon. Pre plug in voltage-12.47. Plugged in voltage 13.52. The fan did not come on when I plugged TT in. Two hours later voltage 13.85, the fan was not running. The plug in at home is a dedicated 20 amp with 12 gage extension cord. The water in the battery is good.

Frank

brookstone345sa · 02-20-2016, 05:31 PM

Is it possible the pedestal at park was not working properly?
I had converter go bad and had no 12v side working , 110 worked fine. I would check wiring in area of battery for loose connections, any inline fuses. If you have disconnect, also check those connections.
I am assuming your 2015 camper has newer battery?
I now always carry a battery charger with me

FrankMor · 02-20-2016, 05:45 PM

The pedestal was fine fridge, WH and AC worked. The only indication we had was the lights dimming then going back bright and the fan coming on.

Frank

brookstone345sa · 02-20-2016, 06:00 PM

Check for fuses on the converter itself. Many of them have 2, 110 side and 12v side.

FrankMor · 02-20-2016, 07:41 PM

I checked the fuses, all are good. There are no reverse polarity fuses that I can find. Out put was 13.65 when I checked at 4:30 and the fan was not running/

Frank

**Bama Rambler** · 02-20-2016, 07:51 PM

Since the heat was on when it happened, it was probably that the furnace drained the battery a little more than the converter/charger could keep up in float mode so it kicked up and naturally the fan came on. That could also have happened if some other high power 12 volt appliance (i.e. Fridge or water pump) kicked on at that moment. Since it's working correctly, I wouldn't worry too much about it.

wahoonc · 02-20-2016, 08:10 PM

Which converter is it? The furnace drawing the battery down faster than the converter could keep up is a possible scenario. I would consider also pulling the converter and check for loose wires behind it too. I have had that happen more than once.

Aaron

pgandw · 02-20-2016, 08:17 PM

I agree with Bama Rambler. Everything is working as it should. When the lights dimmed momentarily (low battery), the converter increased its output, and its fan came on due to the extra heat being generated. By turning the converter off, you delayed recharging the battery, which means the same thing happened each time you turned the converter back on.

On the way home, the DC loads were reduced. No heater fan, no lights, and the battery probably got at least partially recharged by the alternator.

There's a chance your battery will no longer hold a full charge because it may have been run down too far, too often. You might want to have it load checked. Voltage readings on a battery do not given an accurate state of charge until the battery has been idle for 12-24 hours (no charging or load). Voltage readings while the battery is being charged due indicate what voltage the CHARGER is putting out, and can be useful from that perspective.

It sounds like with your loads, a single Group 27 might be a little under-sized. You may want to go to dual batteries to support longer operation without being plugged in.

Fred W
2014 Rockwood A122 A-frame with dual 6V golf cart batteries to run 4 days/nights of dry camping with heat in Colorado Rockies.
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time

FrankMor · 02-20-2016, 09:01 PM

We were plugged in, 50 amp hookup and our lights are LED. The heater was not on when it happened. I had already turned the converter off when we turned the heat on. When I woke up about 2 am, I turned the converter back on. The fan ran till we unhooked to come home, I turned the heat off about 8 am. We turned the AC on about 10 am. The fan on converter never shut off. I plugged in this afternoon and got the readings I posted above. The fan has not ran today. The voltage when I plugged in never went to 14.4 even though the battery was 12.47 before I plugged in.
The converter is a WFCO 8930-50.

Frank

**Herk7769** · 02-21-2016, 08:12 AM

Why would you turn the converter off when using heat?

With the converter off (I assume you needed to trip the AC breaker or unplugged the camper to do this), your battery will not charge. When you turn it back on the converter will need to run a lot to charge the depleted battery (from running the heat on battery alone) and that requires internal fan cooling of the converter components - fan runs till battery is fully charged back up).

Are you talking about a converter or inverter?

If you need to troubleshoot your 50 amp (AC) converter it is very easy to do. I attached WFCO 8900 series trouble shooting guide and manual (in case you don't have one). I know they are 30 amp (AC) panels but the converter inside is the same for troubleshooting.

I also include a link to the WFCO FAQ at their web site:
http://wfcoelectronics.com/faq/#tab-56c9ba155b82f

FrankMor · 02-21-2016, 09:12 AM

The heat was not on when I turned the converter off, the AC was. When I turned the heat on it was late and was not thinking about the converter being off, that is why when I woke up during the night I turned the converter on. I did not have the first guide you sent. I went to WFCO yesterday and downloaded the other ones. I was going to o the quick test they give in their books, but there are no reverse polarity fuses that I can find.

Frank

**Herk7769** · 02-21-2016, 09:22 AM

Quote:

Originally Posted by FrankMor

The heat was not on when I turned the converter off, the AC was. When I turned the heat on it was late and was not thinking about the converter being off, that is why when I woke up during the night I turned the converter on. I did not have the first guide you sent. I went to WFCO yesterday and downloaded the other ones. I was going to o the quick test they give in their books, but there are no reverse polarity fuses that I can find.

Frank

You may need to drop the cover to find them. They should be the only two orange ones there (see my 30 amp WFCO photo for the approximate location of yours).

Be careful in there if the camper is plugged into the campground AC. Even unplugged, never touch the "can" shaped objects as they are capacitors that can retain their power for many minutes after power is removed from the converter.

FYI Frank, leaving the converter on whenever you are on AC power is a good idea because it will maintain your battery in peak condition (using the "float" mode of the 3 stage converter). It will not harm your battery at all.

FrankMor · 02-21-2016, 12:39 PM

Herk
I turned the converter off because I was thinking that it was stuck putting out 14.4 volts since the fan was running all the time. On our motor home, the fan only ran when it was putting out 14.4. I always leave TT plugged in at home, just like we did the MH.
My converter does not have the cutout for the reverse polarity fuses, looking under the edge where they show in WFCO books they are not there, there is a heat sink there. I am going to check voltages, then unhook the ground cable to check the battery voltage. I will take a photo of the converter and try to upload it.

Frank

rireland88 · 02-21-2016, 12:53 PM

We have a WFO8955 converter and the fan runs any time we turn on anything. Repair man said the thermostat is fused and fan will come on anytime we use it. We are waiting for a replacement converter. Not sure why it fused. One battery was not holding charge well may have been on battery charge to long?

Now with the batteries totally disconnected it makes sense since the fan comes on with any DC connection. One light will do it. The fan only runs when the converter is heated up.

**Herk7769** · 02-21-2016, 01:23 PM

Quote:

Originally Posted by FrankMor

Herk
I turned the converter off because I was thinking that it was stuck putting out 14.4 volts since the fan was running all the time. On our motor home, the fan only ran when it was putting out 14.4. I always leave TT plugged in at home, just like we did the MH.
My converter does not have the cutout for the reverse polarity fuses, looking under the edge where they show in WFCO books they are not there, there is a heat sink there. I am going to check voltages, then unhook the ground cable to check the battery voltage. I will take a photo of the converter and try to upload it.

Frank

The way the converter works, it supplies the DC needs of the coach FIRST and anything left goes to the battery. If you are using a high draw (or a few low draw) DC items, the time the converter stays in BULK can be quite long (several hours or more).

Try turning off as much DC items as you can if the battery is low. Also in a motor home you have more than one deep cycle battery that needs to be filled.

As the batteries fill to about 50% capacity, the converter will finally switch from BULK (14.4 Vdc) to ABSORBSION (13.6 Vdc) and remain there till the batteries are nearly full provided the camper demand is low.

NOTE: the converter cooling fan will run in both BULK and ABSORBSION.

From the manual (Bold and Underline mine):

All WFCO power converters are automatic three-stage switching power supplies. The converter senses which mode it needs to be in by checking the RV system voltage.

The three modes/stages of operation include:

Absorption mode/Normal operation Nominal battery charge and supplies power to appliances Bulk mode/Charge mode Fast battery charge and supplies power to appliances Float mode/Trickle charge Trickle battery charge during storage Absorption Mode: During this mode, the converter output is in the 13.6 Vdc range. This is the normal operation mode. This mode provides the 12 Vdc and current required by the 12 Vdc RV appliances, as well as slow charging the battery.

Bulk Mode: When the converter senses that the RV system voltage is less than 13.2 Vdc (equivalent to less than 50% of battery charge) the converter will automatically go into the “Bulk mode.” In this mode, the output voltage of the converter will switch to 14.4 Vdc for a maximum of four hours. If the converter cycles between “Absorption and Bulk mode,” there could be a shorted battery cell or other issues. If the output voltage drops below 13.2 Vdc, the converter automatically changes to a “Bulk mode” 14.4 Vdc (unless the converter is in overload condition). There are two signs of an overloaded converter: Low output voltage, and full converter fold back or shutdown. In both cases, the converter will automatically turn ON, once the complete load is removed. For low output condition, removing the extra (over the current rating) load will be sufficient. If it is impractical to remove all the load, resetting the main breaker will have the same effect.

Float Mode: If the RV is not being used for approximately 48 hours, with a “no load” condition and the shore power is plugged in, the converter will automatically go in to the “Float mode.” In this mode, the converter is charging the battery with a trickle voltage of 13.2 Vdc. When the converter senses a demand (by turning on lights), the converter automatically returns to the “Absorption mode” 13.6 Vdc.

**Herk7769** · 02-21-2016, 01:26 PM

Quote:

Originally Posted by rireland88

We have a WFO8955 converter and the fan runs any time we turn on anything. Repair man said the thermostat is fused and fan will come on anytime we use it. We are waiting for a replacement converter. Not sure why it fused. One battery was not holding charge well may have been on battery charge to long?

Please locate another repairman. The fan can run anytime there is a camper demand and the battery needs charging.

How old is the battery and how has it been treated? Batteries DO die if abused (by discharging them below 50% - abuse - or less than 25% - murder).

That is why folks who boondock have multiple batteries to share the load. This way you can recharge the batteries when they drop to about 75% remaining (12.4 volts).

If you use the "idiot lights" you should plan on starting the generator anytime the "Good" light goes out - 50% capacity when boondocking.

rireland88 · 02-21-2016, 01:34 PM

The fan should not engage until the converter gets warm. With the batteries totally disconnected the fan comes on automatically when any DC appliance or light is turned on. It makes sense to me that there is a malfunction with the fan. Not the converter.

**Herk7769** · 02-21-2016, 01:53 PM

The fan is controlled by a metal oxide versitor located next to the heat sink.

Here is how to test it:

Checking the MOV (Metal Oxide Veristor)

7.1. Position the 8900 MBA (main board assembly) so that heat sink is to the back

7.2. With these instructions leaded MOV (N1) can be checked

7.3. Set the Multimeter to “Diode Test”

7.4. Place “Negative – Black” Multimeter probe on one side of the MOV lead

7.5. Place “Positive – Red” Multimeter probe on the other side of the MOV lead, and the reading should be approximately “0.0” or short (some Multimeter will beep)

7.6. If the reading is OK, Fuse component is good.

FrankMor · 02-21-2016, 02:24 PM

Here is the converter.

Frank

You may also like: