Freezer getting cold but not the fridge?

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CDN_Taxman

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Jun 7, 2010
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230
I've seen the various threads about the fridge needing to be level.

We have our trailer plugged into our home using a 15 amp to 30 amp connector. We have some lights on and the trailers' main fan, the bathroom's little fan and for some reason the freezer's getting cold on AC but not the fridge?

Are we possibly overloading the 15 amp service?

It's hot here.....a 32 Celsius Humidex outside.

I just turned the gas on and moved the fridge to operate on gas only at this point to see if that will help.

As for being level, it's parked on the street and the street is moderately level. I could put the right side up an inch or so. From what I've read, if you're comfortable walking around, it's level enough to get the fridge to operate properly!

HELP!!!! Leaving at 9 AM tomorrow!

Mike
 
Mike, I don't think you will see any difference on gas vs AC.  If the freezer is getting cold, the fridge should be getting cold also.  There are not separate units for each (fridge and freezer)...it works like the home units and one refrigeration system cools both areas.  My experience has been that it takes a good while for the fridge to cool down.  I usually turn it on 24 hr before I load it with cold stuff.  In the heat you describe, it's gonna take a while to cool down.  Not saying you don't have a problem, just saying it won't cool down as quickly as the freezer.
 
I think with all the lights and fans on we may have overloaded the 15 amp system.

The fridge, with the gas on and the fans off and the lights off is now getting cold and you can even hear it hum.

Any thoughts on the overload?

As I said, we leave tomorrow morning, but I wanted to see it chilling after having it plugged in for three or four hours.

Call it inexperienced!

Mike
 
Mike,

With the temperatures you're in, it will take at least 24 hours for the refer to get really cold. If it's only been turned on for three or four hours, how cold it is sounds about right.
 
Morning!

Update.....nice and cold on gas!!!! :) Heading up to a campsite that has 30 amp service. At least if the electrical isn't working (and I believe it is!) we will be just fine!

Thanks for the quick answers!

Mike
 
You mentioned being parked on the street.  You may not be overloading the 15 amp circuit per se, but you might be losing a lot of voltage (voltage drop) if the extention cord is too long and/or too small gauge.  If you have or can get a multi-meter, try to repeat your condition and measure the voltage at the trailer.  It should not be below 109 volts - higher would be better.
 
Low voltage could conceivably slow down the cooling a little bit, but that's a very minor thing. 15A supply is nearly triple what the fridge needs, even with the converter also using an amp or two, so 15A in itself is not the cause either.  Your freezer is getting cold, so the electric unit is working. At those outside temps, it's going to take awhile, as others have said.

The only difference between gas and electric mode is the source of the heat used to drive the cooling process. The electric heat element and the gas flame heater are almost side by side in the cooling unit and it doesn't really care which one supplies the heat.  The cooling unit chills the freezer first and then extends to the fridge area, so when it's really hot (inside and out), it takes quite awhile to chill everything. The fridge will actually cool faster if you fill it with cold stuff. They don't do well chilling an empty box of air, especially when you open the door to check on it and the cooling air falls out to the floor.
 
Right before we left for a 2 month trip this past June, we got a recall notice on our Norcold 1200 4 door fridge.  We were able to get the recall work done and began preparing to leave.  It took forever for the gas to cool the fridge and never did get it any where near cold until we were in a campground and it switched over to electric.  We were packing in 90-100 degree weather.  I was convinced the gas portion was not working and worried about it for days.  We run our generator while driving, so it was on electric most of the trip; but I still worried the gas portion was not right.  We had to park in a dry camp for a couple of days and I dreaded using the gas because I was convinced it was broken.  It wasn't....it kicked in and kept everything cold. 

However, I have noticed since the recall repair that it is not freezing things in the fridge part like it used to.  The repair consisted of replacing the aluminum sleeve over the gas flame and inserting a control device to not allow the sleeve area to overheat causing a fire.  So, I'm wondering if that had an affect.

Marsha~
 
RV Roamer said:
Low voltage could conceivably slow down the cooling a little bit, but that's a very minor thing. 15A supply is nearly triple what the fridge needs, even with the converter also using an amp or two, so 15A in itself is not the cause either.  Your freezer is getting cold, so the electric unit is working. At those outside temps, it's going to take awhile, as others have said.
Maybe picky details, Roamer, but it really doesn't make any difference if the circuit is 15A or 150A when it comes to voltage drop along the distribution line (extension cord).  The heating element is a resistive device and lower voltage will cause lower current draw - and consequently less heat.  How much "less heat" would it take to affect the cooling down of the fridge may be debateable.  But, a resistive heating element running at less than optimum voltage will drop heat output pretty rapidly.  I agree that the OP probably does not have a problem with his fridge, but I'm not sure his fridge would have ever reached normal temp if it was receiving low power.
 
molaker said:
Maybe picky details, Roamer, but it really doesn't make any difference if the circuit is 15A or 150A when it comes to voltage drop along the distribution line (extension cord).  The heating element is a resistive device and lower voltage will cause lower current draw - and consequently less heat.  How much "less heat" would it take to affect the cooling down of the fridge may be debateable.  But, a resistive heating element running at less than optimum voltage will drop heat output pretty rapidly.  I agree that the OP probably does not have a problem with his fridge, but I'm not sure his fridge would have ever reached normal temp if it was receiving low power.
Actually a lower voltage will cause an increase in current draw.  Ohms law never fails.  For ease of numbers lets say the heating element draws 360 watts.  At 120 volts  that is  3 amps.  At say 90 volts the current draw would be 4 amps.  Either way it is still drawing 360 watts.
 
Sorry, but the power used by a resistor is a function of applied voltage. If you put the heater in series with another resistor (extension cord), the overall resistance is increased and the current decreased; heat output (from the heater) will be lower! In the example, the heater output watts would drop by about 25% since 25% of the voltage is dropped in the cord.
Ernie

PS If we were discussing an inductive load (motor), it would be a different thing.
 
Macrosill said:
Actually a lower voltage will cause an increase in current draw.  Ohms law never fails.  For ease of numbers lets say the heating element draws 360 watts.  At 120 volts  that is  3 amps.  At say 90 volts the current draw would be 4 amps.  Either way it is still drawing 360 watts.
Interesting.  After over 40 years of electronics, I was always told that reducing the voltage across a resistive device reduced the current through it.  You are right in that Ohm's law never fails.  I = E/R - reduce the voltage (E) and the resulting current (I) goes down.  As for power, P=I*E (simplistically).  The example you made is incorrect.  Wattage is controlled by the voltage and current, not the other way around.  The heating element will not consume the same wattage when the voltage is reduced.

Now, a lower voltage can and usually does result in an increase in current when dealing with devices such as AC motors (reactive devices).  As a motor slows down the counter EMF produced goes down effectively reducing opposition to current, thus increasing current.  This is why motors (A/C compressors, etc.) pop circuit breakers if they don't start up properly.

Edit - Dang, Ernie, you beat me to it.
 
Brian,

Methinks you misunderstood Ohm's law: I = V/R or, transposing, R = V/I

So, assuming for simplicity that the heating element is purely resistive:  R = V/I = 120/3 = 40 ohms

At 90V, I = 90/40 = 2.25 amps.

Power = V X I = 90 x 2.25 = 202.5 watts

Edit: Oops, Ernie & Molaker beat me to it.
 
There are some side effects such as resistance generally increases with increasing current. but in general, Ohm's Law doesn't lie :)
 
I've had the same problem with my fridge, the freezer was cold and the fridge wasn't. I discovered I had a climate control switch, which had been turned on. I turned it back off and that FIXED the whole problem.

Also, you need to fill the fridge with water jugs, when you don't have food to cool. The RV fridge doesn't cool the air, but cools "things".  So if you are trying to cool it down empty, it may seem awfully warm. Put some large water jugs in and it will cool right down.  Then you can remove the water jugs and replace with food, when you shop.

I travel with a few spare gallons of filtered water "just in case" so I put these in when the food runs low, and remove them when I need the space again for food. I also fill up ice trays to freeze, them empty those into an rectangle ice bucket in the freezer, so the freezer has stuff to freeze etc. 

Invest in a thermometer for the refrigerator.  How I wish all refrigerators came with these built in!  I used to be a chef, so maybe I am super paranoid about the temperature. I am happy to give it a quick glance every time I open the fridge, to verify all is well. Sometimes I pop it in the freezer for awhile, to check that it is OK too.

Clean the seal of your refrigerator and freezer with gentle soap and water (like Joy soap) to make sure you are getting a good contact when it is closed.

YES, refrigerators can malfunction when run crooked and staionary. Apparently bouncing down hilly and curvy roads, keeps the freon juggled around, so it doesn't get stuck. When running unlevel and stationary, the freon stuff can clog up the system permanently and cause costly repairs.

It pays to spend a few minutes to level up the trailer or motorhome to keep the expensive refrigerator happy.  I travel alone in an old motorhome that requires boards to level up with. I bought a 12 foot treated  board at Lowe's as wide as the tires, then had them saw it up into four 30 inch pieces, which left me one 24 inch length, so I got 5 boards out of the 12 feet. I already had two boards, so now I have seven.  When I need 2-3 boards to level up, I arrange them like steps with about 2 inches between each step, then drive up (or reverse) on the boards.  Even by myself, it only takes a few minutes to unload the boards, place them by the tire(s) then level up.

After doing it so much, I can pretty much look at the level gage, then predict how many boards I need, and pretty often get it right the first time around.

Once I shut off the Climate Control switch, my refrigerator has run perfectly. I understand the Climate COntrol swith runs on 12 volt and heats up the seal to prevent outside condensation. I haven't had the problem, and I don't know if my switch is malfunctioning or what, but I keep it off and the fridge works fine ever since.
 
In the example, the heater output watts would drop by about 25% since 25% of the voltage is dropped in the cord.

Actually, the power drops off according to the square of the voltage loss.  Power = E squared / Resistance

A 10% voltage reduction (120 volts to 108 volts) gives a 23% drop in wattage, lower the voltage by 25% (120 volts to 90 volts)  and you're looking at 56% of the the original power.

The heat produced by a resistance heater will decrease by the same amount.  At 108 volts it's producing about 3/4 of it's rated output, at 90 volts it's producing about half it's rated heat.

So if you're in a brownout condition (low voltage to the rig) your fridge will cool better if you switch it to propane.
 
Tom said:
Brian,

Methinks you misunderstood Ohm's law: I = V/R or, transposing, R = V/I

So, assuming for simplicity that the heating element is purely resistive:  R = V/I = 120/3 = 40 ohms

At 90V, I = 90/40 = 2.25 amps.

Power = V X I = 90 x 2.25 = 202.5 watts

Edit: Oops, Ernie & Molaker beat me to it.

WOW I FEEL STUPID

WOW
 
No reason for anyone to feel stupid. Some of us took electrical and electronic engineering, and Ohm's law is kinda like a baby's first steps for us.

I never took a chemistry class so, when our resident chemists talk chemistry, I feel a little inferior.
 
Ok, who's going to bring up Kirchoff's laws?  That should really confuse things :)
 
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