Norcold 1200-series refrigerator defrost

[ronboc]

Hi -

How often does/should the frig go into the defrost cycle? Seems like mine does its thing about every 2-days, but sometimes seems longer (or maybe I just don't catch it when it's doing it).

And what triggers it? (ie, overall time between defrosts, number of door-openings, temp-rise, etc)

TIA,
Ron

[ronboc]

Hi -

How often does/should the frig go into the defrost cycle? Seems like mine does its thing about every 2-days, but sometimes seems longer (or maybe I just don't catch it when it's doing it).

And what triggers it? (ie, overall time between defrosts, number of door-openings, temp-rise, etc)

TIA,
Ron

[RV Wizard]

Ron, I think the defrost cycle is determined by the number of times the doors have been opened. If you will give me the serial number I can find out the answer for sure.

[Carvin Marvin]

I have an 02 model 1200. What defrost cycle? Are we talking about frost on the fins? Marv

["007"]

When frost builds up on the cooling fins from door openings, humidity and heat content of foods placed in refridge the fridge control unit will remove the excess frost in timed intervals. This LINK PDF will explain on pg 10 Defrost. Its not the same as when you defrost the refridge on closing or when freezers are in need of defrosting manually.

[ronboc]

Hi Mike -
I'd sure appreciate it if you could find out, it's driving me huts trying to figure it out on my own. The service and operator manuals reference the function but don't give details. Mine is 1210IMSS, with serial number 10089434.

Carvin -
I can't say for sure but I think yours operates the same way... Every once in a while (and I'm trying to figure the 'when'), these things will shut down the cooling cycle allowing the fin-temperature in the upper-rear of the frig-box to creep up above 32F and self-melt the frost that has collected on the fins. The melted water then drains down and outside to either a small collection-pan or simply exterior to the coach. After another period of time (and how does it know THAT time too?), the cooling will turn itself back and drop the temperature back to its regular setting. The freezer portion does not have a similar function (ie, like a home-type frig), it's just supposed to stay as cold as it can while the frig-part gets warmer, and we do a manual defrost when appropriate.

007-
Thanks for the link to the manual. It does describe the defrost function as you pointed-out, but nothing about its frequency or operation.

By the way-
I did find a dealer who said he "thought" it was on a "49-hour" repeat cycle, but am not sure if that's someone's anecdotal observation or a real NorCold fact. If so, what confuses me now is the 49 hours vs something like 48 hours. Gee, if you could set it (Hey! Now there's another question... can you set/change it to your liking? Ie, like in really dry or really humid climates, the standard setting may not be suitable) to go on/off at 3am consistently, them the box wouldn't have to struggle as much to keep up as if it got to cycling at 2pm when people are in/out of it and it's also the warmest part of the day.

Thanks!
Ron

["007"]

Ron if you read further into the defrost section you will see that the control unit determinds when the "frost build up" will need to be removed. There is no adjustment to increase or decrease interval.
If you are having box temperture problems as to being to high out of the upper 30* range make sure no problem with your cooling fans above the cooling coils.

[ronboc]

Hi 007 -

Box temps are as they should be, and my fans are working correctly.

Yes, I did see the part where it said: "...At regular intervals, the temperature control system automatically melts most of the frost from the cooling fins....". My question however is 'What Are The Regular Intervals' and 'What Determines The Interval' in the controller? Is it based purely on time, or door-openings, running hours, or something else?

Thanks!
Ron

["007"]

Ron, I beleive the thicknest of frost on the fins determines the time to defrost, the thermal sensor on fin doesn't like the frost on it.

[footdoc]

I am able to closely follow box and freezer min and max temps with my installed in/out thermometer. I had noticed that the box temp would get up to about 40 and the freezer up to about 24 every so often...with NO door activity. I thought something was wrong until I called Norcold and was told there is an automatic defrost cycle that kicks in every "49 hours"...Seems about like that's what it's doing..I just didnt like the temp swings without having a reason...now I know why..and it feels better!!!

[ronboc]

AH-HA! So that solves the mystery (....well, at least based on another version of the 49-hour cycle version). Thanks Larry.

I too didn't like the idea of the entire frig-compartment getting up to maybe 42F while the freezer compartments slowly crept up to the mid-teens when it went into defrost before cooling back down again, so I 'hurried' things along. After shutting the entire box down, I put a tupperware pan of warm-water on the top-most grid right next to the frig-fins - replacing the water as necessary - til all ice/frost melted off the fins. Then I turned it back on again and watched it. The freezers never got above -1 while the lower part of the frig never got above 38 during the melt, and were able to get back down to normal that much quicker.

Works for me.

[DancinCampers]

In 2005 at the Winnebago National Rally I attended a seminar by a Norcold Rep. My notes says the defrost cycle is set for 49 hours. He said to trick it (reset timer to zero) turn unit off, then on.

I don't think this info was given as model specific.