2001 Dometic fridge issues

[yetavon]

Bought a 2001 5er and the fridge worked fine on gas, on electric the freezer is almost 0 but the fridge is almost 60...outside temps 90+.
any ideas?

has been plugged in a few days

[MacGumbo]

Early on was the fridge working and after a few days warmed up or did it not cool down from the start?

[Bama Rambler]

I would take some amp readings on the electric element while it's on and see if it's drawing the current that it should be. A loose connection would cause it to not heat as well as it should.

Also check to make sure it's the rated wattage for that fridge.

[yetavon]

1st started on gas and run a few days testing. Then a few weeks later we plugged it in on shore power. Seems on electric it cant keep up with the heat of the day, was on the edge of cold enough in the morning but up to 56 at 3....but freezer still frozen.

[Toddupton]

The element most likely is not putting out the correct amount of heat. Check the voltage and amp draw and see what the wattage is.

[Herk7769]

That is a great point. Missing is the length of the cord between the camper and the source of the AC. If you are using an extension cord, you may not be getting the voltage you need at the camper to generate the watts needed for cooling.

A long extension cord is like a choke collar burning up amperage on the way to your camper generating heat outside. that reduces the voltage at the camper.

The Fridge heater is about 41 ohms and one formula for power is P=I (current) times V (voltage).

Since have a 325 watt (P required for 100% efficiency) heater element for cooling at 120 volts. At 120 volts you will draw about 2.7 amps.

If the voltage drops to 100 volts, the resistance of the heater does not change, so to now find out the available power you P= V Squared / R.

So what is the power available at 100 volts = 100x100/41 or only 244 watts (or 75% efficiency).

[yetavon]

The cord length may be the culprit for sure... Its a 100 ft 12 ga construction cord,with adapters going from 20 to 50 amp....ran the AC just fine....Ill bring our Kill-A-Watt over later....this morning on the way home, fridge was @ 38. switched to gas and it fired up.
Proper wiring is in the works...

[Herk7769]

Originally Posted by yetavon

The cord length may be the culprit for sure... Its a 100 ft 12 ga construction cord,with adapters going from 20 to 50 amp....ran the AC just fine....Ill bring our Kill-A-Watt over later....this morning on the way home, fridge was @ 38. switched to gas and it fired up.
Proper wiring is in the works...

"Just fine" is a relative term when it comes to inductive loads. Without knowing how low the voltage drops during compressor startup, you could be burning up the AC and not even know it till its too late.

You need to monitor the AC voltage when using a long extension cord and never use the Air Conditioner at all. It will have severe voltage drop and may be why your Fridge won't heat very well on shore power.

Oh and Kill-a-Watt may not show voltage, I forget.
You should have one of these in your tool box to check the campground power anyway. They are cheap and work great.

[yetavon]

I understand the basics of electricity, and was concerned with the AC testing...It was the only thing on at the time...Hope to get my 50 amp service run out this week.. got everything but the time...
Back to the fridge...hottest day of the year (the 22) and freezer still froze but fridge at 78 this time....seems this model when mounted in a slide has major drafting issues due to no roof vent. to add insult to injury, its set up with that side in direct sun most the day. Its off for the time being, will mount a fan to help move the air and retest later this week.