MattSmith

OK, Folks, here's my latest. This really does work! I treated myself to an Amprobe AC/DC clamp-on ammeter and found that our Norcold frig draws 2.7 amps AC on shore power, or about 324 watts at 120 vac. I then bought a 400 watt (rated continuous output) inverter ($59, half what the meter cost!) and wired it to our house batteries (two 12v deep-discharge type) and plugged the Norcold into it. It runs nicely - - doesn't know it isn't on shore power - - and the inverter draws a little over 30 amps dc from the batteries (360 watts or more at 12 vdc, since efficiency is never 100%). This particular inverter (a "Westward" from Grainger) shuts itself off if the input voltage falls below 10.5 volts, and is said to handle momentary surges to 600 watts. We're just back from our second one-week outings and are happy with it so far. I did forget to switch to propane one time and the inverter shut down some time during a 4-hour absence, but nothing warmed up much because we weren't there! No doubt a bigger, domestic-type frig would require more watts, but the principles apply. As to driving with propane turned on, I guess we're responsible for our own phobias! Our first encounter with motorhomes was back in 1982 when we rented a 34' Southwind for a 5-week cross-country trip. The rental agent was adamant that we must never, never have that valve open when on the road, and we took that as received truth. And really, I wouldn't want to get broadsided and have that regulator get snapped off with the valve open - - Happy holidays to all! - - Matt S.

Thanks again, Brett & Gary - - We do in fact, perhaps superstitiously, drive with the propane turned off at the tank. I guess I'm more worried about a propane line getting ruptured in a collision than I would be about the small flame in the fridge. Looks like I can buy a lot of fuel for the effort and cost of a suitable inverter plus possible shortened alternator life. It's still tempting, though, and I'll post any outcome if I give in to temptation! (With the inverter, I could at least use my electric drill while dry camping - - ! ? !) Keep 'em flying! - - Matt Smith

Thanks for the responses, Gary and Tom. Our fridge runs well enough on propane, but all received wisdom dictates against traveling with the propane turned on, since it could be a pretty catastrophic fire hazard in any driving mishap. Tom, since this fridge has no DC option as installed, my scheme would be to use a 600 watt (continuous-rated) inverter to provide AC from the (DC) house batteries. I find that the engine alternator does indeed charge the house batteries when the engine is running, and from a simple "watts out = watts in" thought process I was guessing that if the fridge demanded, say, 480 watts AC, the alternator would have to put a bit more than 480 watts DC, or 40+ amps at 12 volts, into the inverter when the fridge thermostat called for cooling. This seemed substantial but not too outrageous, and I was curious whether others had tried it. I guess the worst that could happen would be that the batteries would run at a deficit whenever the alternator couldn't keep up, then hopefully catch up when the fridge thermostat was satisfied. The coach does have a 100 watt inverter intended for TV when dry camping, but we've never used it and it's way too small for this. My premise in all this is that the 454 Chevy V8 is running anyway, and ought to use a lot less fuel incrementally than running the 4000 watt generator. Just have to remind myself to smile while fueling the coach! Cheers! - - Matt

We're tempted to try installing an inverter to run the Norcold refrigerator on DC while driving in our 1994 Winnebago Adventurer. We have a couple of questions: 1. Does the engine alternator maintain the house batteries while driving? 2. I don't know the actual power consumption of the refrigerator on AC, but the Norcold schematic appears to show a 5 amp fuse in the AC heater circuit, so it can't be over 600 watts, and there are inverters available in this range. The same Norcold schematics show a 20 amp fused, separate heater for units with the 12 volt DC option (which we wish we had), obviously less effective than either AC or propane operation. The question: can the engine alternator handle the power requirements of the refrigerator in its normal AC mode, either via the engine battery or the house batteries? 3. Obviously I need to get a clamp-on ammeter and actually measure the AC current demand, but a meter costs more than an inverter would, and this is just in the thinking stage. Right now it's easier to see if the kid in the next seat knows the answer! 4. On paper, this would seem more efficient than just running the generator for the sake of the refrigerator. What am I missing, that the motorhome manufacturers know and I don't? - - Matt S.

OK, time for me to own up! Your very first question about the thermostat made me actually look at it, which I hate to admit I had not done. It's up in the top right corner of the fridge, near the ceiling, where the light isn't very good (EXCUSE ALARM FLASHING!). Has settings numbered from 1 to 5, reading left to right. The left end of the scale is clearly labeled COLD. The right end of the scale, which I never looked at until just now, is labeled COLDEST. We had the thermostat at the extreme left end, with obvious results. It's now an hour later and the freezer is down to 10 and the fridge about 40 and dropping. Many thanks for your help! This thing has received more TLC in the last three days than in the 2/3 of its life that we've owned it. Cheers! - - Matt S.

Reading these commentaries with great interest as I'm having a similar problem with the Norcold Model 6162 in our 1994 Winnebago Adventurer. On electric operation, the best it will do is about 47 deg. F in the fridge, 16 or so in the freezer, even at outdoor temps in the 70's (in "temperate" Connecticut) with an electric fan blowing into the exterior access hatch. Gas operation seems no better, no worse. Nice blue flame, lights and runs OK. I can see daylight from the coach roof thru the ventilation area between the back of the refrig unit and the outsided wall of the coach; nothing like bird or mouse nest etc. that I can see with mirror. There is a condensation drain and receptacle , both bone dry, end of hose apparently pinched at manufacture to prevent back leakage of air. I took out the burner and its heat shield and was able to "bump" the flue up and down about a half inch, loosening up a lot of rust, which I vacuumed away. The "dollar bill" caper show both door gaskets OK. In this installation it looks physically impossible to do much more without detaching the refrig unit from the coach for acces to the back side, which I'm loath to do as you can guess. - - Not sure about putting a new unit in a coach this old, but it's doing what we ask it to (mostly!) All suggestions welcome! - - Matt S.