starting up refrig...lp or electric

dougrainer wrote:

MitchF150 wrote:
I always just run my fridge on gas, even when plugged in.. Just cools better overall for me and I'd rather have the flame instead of a glow plug doing the work..

Just what I do and it works for me.. Don't care what other's do, nor what they think I should do.. :)

Good luck!

Mitch

People can do what they want as you stated. Just because they can does not make them an expert at how they do things. Your idea is wrong. It is NOT just a "Glow Plug". But, you do what you want and waste money on LP when in most cases your Electricity is part of your CG fee, so on 120 your refer runs for "free". There is NO way for anybody to actually determine that LP works better than 120 and vice versa. Doug

Hi Doug. I did just say it's "what works for me".. Not that I ever claimed to be an "expert" in any way in my post either..

I also have one of those fridges that was recalled for the electric element causing the pipes to crack and leak out the stuff, either causing a fire, or rendering your fridge useless..

And all the recall did was put in some sheet metal to divert the leaking stuff away from the flame if it did crack.. Not fix the actual issue itself, which was too hot of an electric element.

I use more gas to fire up the BBQ for a couple of steaks than the fridge would use over a whole long weekend trip.. No big deal in the grand scheme of things as far as I'm concerned.

Thanks,

Mitch

Hi TomG2,

http://www.maxmcarter.com/fuels/calc_fuels.php?Erate=0.125&Grate=3.73&unit=Propane+per+gallon&Ef=65

TomG2 wrote:
One will discover that it is pretty costly to run a RV refrigerator on electric at $0.165/kwh that I pay. I pay $12.00 for a twenty pound cylinder of propane. Propane is cheaper.

Having said all that, I am not going wrestle around propane tanks in the middle of summer to save a few dollars.

TomG2 wrote:

dougrainer wrote:
....snip....... There is NO way for anybody to actually determine that LP works better than 120 and vice versa. Doug

I can come pretty close, as I run my refrigerator on gas for ten days, switch to electric for ten days, back to gas for ten days, and ten days on electric, and so forth, for the season. Interesting results and it ALWAYS saves electricity on gas. How much? Your results will vary, so mine only applies to me. I pay for both propane and electricity, so I wanted to know. (I enjoy quantifying things rather than giving opinions without facts)

I think you missed my point. NOBODY can really determine which(LP or 120) operates the refer BETTER. The process takes so much time it would drive anybody crazy trying to determine that LP or 120 is BETTER at cooling. The design parameters(BTU's) are almost identical. FYI, MOST of my troubleshooting happens when outside temps are above 85 degrees and ALL my testing is done on 120, unless the complaint involves problems on LP. I would NEVER run my refer on LP unless the Line voltage was below 110 volts. Doug

One will discover that it is pretty costly to run a RV refrigerator on electric at $0.165/kwh that I pay. I pay $12.00 for a twenty pound cylinder of propane. Propane is cheaper.

Having said all that, I am not going wrestle around propane tanks in the middle of summer to save a few dollars.

TomG2 wrote:

dougrainer wrote:
....snip....... There is NO way for anybody to actually determine that LP works better than 120 and vice versa. Doug

I can come pretty close, as I run my refrigerator on gas for ten days, switch to electric for ten days, back to gas for ten days, and ten days on electric, and so forth, for the season. Interesting results and it ALWAYS saves electricity on gas. How much? Your results will vary, so mine only applies to me. I pay for both propane and electricity, so I wanted to know. (I enjoy quantifying things rather than giving opinions without facts)

Trouble is the systems are mixed. Would be interesting to see how long the fridge would operate on 30 pounds of propane and the run for the same time on electric using a dedicated meter to show total kWh.

But that is about running cost, not start up as the OP asked.

dougrainer wrote:
....snip....... There is NO way for anybody to actually determine that LP works better than 120 and vice versa. Doug

I can come pretty close, as I run my refrigerator on gas for ten days, switch to electric for ten days, back to gas for ten days, and ten days on electric, and so forth, for the season. Interesting results and it ALWAYS saves electricity on gas. How much? Your results will vary, so mine only applies to me. I pay for both propane and electricity, so I wanted to know. (I enjoy quantifying things rather than giving opinions without facts)

MitchF150 wrote:
I always just run my fridge on gas, even when plugged in.. Just cools better overall for me and I'd rather have the flame instead of a glow plug doing the work..

Just what I do and it works for me.. Don't care what other's do, nor what they think I should do.. :)

Good luck!

Mitch

And, I always run mine on electricity when available, and gas only when necessary. I'd rather save the gas for the furnace on cold nights.

MitchF150 wrote:
I always just run my fridge on gas, even when plugged in.. Just cools better overall for me and I'd rather have the flame instead of a glow plug doing the work..

Just what I do and it works for me.. Don't care what other's do, nor what they think I should do.. :)

Good luck!

Mitch

People can do what they want as you stated. Just because they can does not make them an expert at how they do things. Your idea is wrong. It is NOT just a "Glow Plug". But, you do what you want and waste money on LP when in most cases your Electricity is part of your CG fee, so on 120 your refer runs for "free". There is NO way for anybody to actually determine that LP works better than 120 and vice versa. Doug

Hi myredracer,

Thanks for the information. I can say that my fridge works well at 100 volts and that the element draws 325 watts @ 120 volts. That works out to 2.7 amps.

By works well I mean that fridge temperature stays at 37 F on 120, 110, and 100 volts.

I'll redo the calculations manually--I used an online power (wattage) drop calculator. Clearly, I picked the wrong calculator!

I can't hold onto an 1156 bulb--let alone a 100 watt.

pianotuna wrote:
Since the power factor on AC voltage is 1 for resistance heating devices, going from 120 volts to 110 volts represents a power loss of only 27 watts. My own fridge works well down to 100 volts (a loss of 54 watts, or about 1/2 the heat of a candle).

In your example, you'd be down to 84% of the rated output of the element in the fridge at 110 volts so if you have a 300 watt element, you've lost 48 watts and at 100 volts, 93 watts. Not sure about Dometic but Norcold specifies a min. of 108 volts.

The output of any resistive device, like a heating element, varies as the square of the voltage. (Ohms law.) If the voltage happened to be down to 104 volts, the point of a PI EMS cutting out, it's lost 25% of it's normal output. At 100 volts, it would have lost 31% of it's normal output. That amount of drop is significant and I would guess that the cooling output of the fridges drops faster than the corresponding output drop in the heating element. Try holding a 25, 60 or a 90 watt incandescent light bulb and see how long you can hold on!

I believe the elements in RV fridges are all rated for 120 volts but as many of us know, CG voltage can get pretty low sometimes. That's where an autoformer can really help. Same with toasters, coffee pots, hair dryers and the like.