Suburban furnace & WFCO Ultra distribution panel

Rhodeena · 10-22-2013, 04:32 PM

I'm wondering if the Suburban furnace fan is run off the battery or 110. It seems that whenever the furnace fan kicks on the lights dim dramatically. I've sent out an email to Suburban. Any ideas?

**wmtire** · 10-22-2013, 04:34 PM

Your furnace and lights both run off of 12 volt DC (battery)

Here are more detailed explanations of your RV's electrical systems:

http://rvservices.koa.com/rvinformat...lectricity.asp

http://rvservices.koa.com/rvinformat...d-amp-draw.asp

OldCoot · 10-22-2013, 04:38 PM

Quote:

Originally Posted by wmtire

Your furnace and lights both run off of 12 volt (battery)

Basic RV Electricity - RV Information (RV Maintenance)

RV Converters and Amp Draw - RV Information (RV Maintenance)

True, except for the ceiling fan lights in our 5er.

raspivey · 10-22-2013, 04:40 PM

Correct, and the dimming I've found to be the symptom of the factory putting in the highest gauge wire they can get away with...I'm sure for cost savings. The resistance caused by the thinner wires restricts the amount of power getting to everything, noticeable when you put a heavy draw on it.

OldCoot · 10-22-2013, 05:27 PM

Quote:

Originally Posted by raspivey

Correct, and the dimming I've found to be the symptom of the factory putting in the highest gauge wire they can get away with...I'm sure for cost savings. The resistance caused by the thinner wires restricts the amount of power getting to everything, noticeable when you put a heavy draw on it.

It's only a momentary dimming and also takes place in houses when a big appliance is turned on.

garbonz · 10-22-2013, 05:52 PM

It called voltage sag, and happens cause the converter takes a few second to catch up to the sudden change in amp draw, and the battery drops a few 1/10's of a volt.

Rhodeena · 10-23-2013, 08:23 AM

I'm new to RVing and spending the winter in a 2005 SalemLe I bought used. So all of this is new to me. The manuals, as with all manuals these days, just seem to glaze the surface. Where I'm parked, on a construction site, I'm boxed in and can't take the RV to a dealer until one of two dirt piles are removed. Long story short, how can I tell if the battery needs replaced? This am the overheads were strobbing while the furnace was running. I checked the battery, it read E. Turned off the overheads it read 1/3. Turned off the furnace, it read full. The battery was replaced, according the records, in 2011. The RV was used one weekend a month during late spring through early fall and then the entire month of October. The unit was always plugged in except when in haul.

**wmtire** · 10-23-2013, 08:36 AM

Rhodeena, are you plugged into a form of 120 volt shore power (ie power outlet, generator)?

If plugged into shore power, your converter (explained in the second link I provided in my previous post above), is what provides the 12 volt power to the items that require 12 volt.

It's possible you may have a converter going bad.......or a battery too.

The converter is also what recharges the battery, when you are plugged into 120 volt shore power. Some converters do a better job of charging than others. It's also possible to boil that water out of a battery if the charger isn't a good 3 stage charger (some are, some aren't).

If not plugged into shore power, then it's all running directly from the battery.

Rhodeena · 10-23-2013, 08:41 AM

I am plugged into a dedicated 30 amp outlet. I've read the first article you sent and I'm preparing to read the second. I put water in the battery this past Friday. I will check to see if it's "boiling" out. Also, I'm the only unit on site.

**Herk7769** · 10-23-2013, 08:42 AM

Quote:

Originally Posted by raspivey

Correct, and the dimming I've found to be the symptom of the factory putting in the highest gauge wire they can get away with...I'm sure for cost savings. The resistance caused by the thinner wires restricts the amount of power getting to everything, noticeable when you put a heavy draw on it.

Dimming under load is nearly ALWAYS a bad ground or battery.

Examine your ground connections. Frame ground screws are notorious for rusting and losing a good connection.

garbonz · 10-23-2013, 08:58 AM

Under normal conditions when you are plugged in, the converter should prevent dimming or voltage loss (same thing) regardless of the battery condition.

You have a converter or wiring (ground) problem for sure. Your battery may also be bad but that is secondary to the issue at hand. The ground connections should be check first, then the converter. The OEM converters are pretty prone to failure.

Rhodeena · 10-23-2013, 09:25 AM

Lou, stupid question. Where are the frame ground screws?

BarryD0706 · 10-23-2013, 09:43 AM

Follow the negative lead from the battery. It's where that connects to the frame.

There will also probably be a connection to the frame in your power distribution center (breaker/fuse panel).

**Herk7769** · 10-23-2013, 12:15 PM

Quote:

Originally Posted by BarryD0706

Follow the negative lead from the battery. It's where that connects to the frame.

There will also probably be a connection to the frame in your power distribution center (breaker/fuse panel).

They are located underneath the frame and location varies by model.

Like Barry said, the first stop should be battery ground. The second the converter ground. There are others (like the photos) that may only be seen by dropping the belly panel.

Rhodeena · 10-23-2013, 01:32 PM

I found a loose ground near the land electric cord. Not sure what it is for as it disappears into the belly panel. When I turned on the heater and all the lights while the water heater was on there was no strobbing of lights. Thanks to all who responded. I will keep you posted of the effects this pm and am.

Rhodeena · 10-24-2013, 09:30 PM

So, all seemed to be well last night until 3:30 am when I was awakened by the converter's struggle to run the battery. Battery voltage was 9, replaced battery and all seems to be well this evening.

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