12v Fridge Install

[markcee]

Just ordered a Norcold N10DC 12v fridge to replace my gas/electric Dometic and have some pre-install questions. Trailer is not at the house to check, but am anticipating the existing 12v wiring will not be properly sized to simply re-use. I will likely need to run 8 or 10 gauge (depending on run length) to meet the new fridge requirements. The fridge is in the driver's side slide and the power center is under the center island - almost directly across from the fridge.

1. Will the existing wiring be running and accessible through the underbelly? If so, any tips on dropping and reattaching the coroplast? My plan is to swap the existing fridge wiring with the new, attaching it to the same 15a circuit in the power center. I believe the coroplast is riveted in place.

2. I've seen some info about connecting directly to the battery with an inline fuse. What are the pros/cons of this? It may be an easier run to make with the wiring.

Here is the install manual for this fridge. Being not so electrically inclined, I have to say I am not 100% my plan(s) are appropriate. Appreciate the opinions of forum members on how they would wire this.

By the way, Amazon has a great deal on this fridge right now at $1277 with free shipping. (I missed the $1219 price sitting on the decision overnight).

[chuckster57]

If the coroplast is nailed in, you can do whatever it takes to remove them and replace with stainless steel self tapping screws and washer.

Your existing 12V wiring will be in the bundle coming out at the bottom corner of the slide. Most likely in the split loom, and will enter the underbelly at that point.

You can remove the power distribution panel to access the 12V wiring, it will either go up to the ceiling or down through the floor. If there isn’t any holding tanks in the way, a “fish tape” will make running the wire easy.

Don’t forget to cap off the propane line at the frame where the flexible hose attaches and test for leaks. This project is more labor intensive than difficult.

[markcee]

Originally Posted by chuckster57

If the coroplast is nailed in, you can do whatever it takes to remove them and replace with stainless steel self tapping screws and washer.

Your existing 12V wiring will be in the bundle coming out at the bottom corner of the slide. Most likely in the split loom, and will enter the underbelly at that point.

You can remove the power distribution panel to access the 12V wiring, it will either go up to the ceiling or down through the floor. If there isn’t any holding tanks in the way, a “fish tape” will make running the wire easy.

Don’t forget to cap off the propane line at the frame where the flexible hose attaches and test for leaks. This project is more labor intensive than difficult.

Thanks Chuckster. I just took a ride to the storage place and took a look in the fridge compartment. The pair of wires I was planning on using are circled in the pic. They are pink/white and white. I believe they are 10 gauge (as tested by my wire stripper). I was trying to verify this by looking at the Keystone Wiring Standard, but I'm not certain what the individual numbers in the chart refer to when describing some circuits. The pair of wires I'm looking at indicate a '12v Accessory Circuit' and state 10 gauge for '1' and 14 gauge for '1,2,3'. Also, this bundle of wires is coming down from the top, instead of from below. Since you mentioned the bottom, am I looking at the wrong bundle of wires?

Can you verify this is the appropriate pair of wires and also, since this is listed as an 'accessory circuit', in the Keystone guide, is it OK to use for this application or do I need to run something that's dedicated to the new fridge only?

Thanks!

[chuckster57]

The 2 wires that are attached to the plastic block, where do they go? If you look under the slide, is the same color wires in that split loom?

The normal routing of wiring both 12VDC and 120VAC is underneath, not over the slide.

[markcee]

Originally Posted by chuckster57

The 2 wires that are attached to the plastic block, where do they go? If you look under the slide, is the same color wires in that split loom?

The normal routing of wiring both 12VDC and 120VAC is underneath, not over the slide.

I'll have to wait to tear into it to find out exactly where they go. All I know now is that they are definitely in that bundle the arrow in the pic is pointing at which is coming from above, not below.

Fridge is coming next week, when it does I'll bring the trailer home, run the slide out and try to figure things out then.

[markcee]

I got the old propane/electric fridge out and the new Norcold 12v installed and all seems to be working well. I ended up going directly to the battery with 8 gauge stranded wire, with inline fuse near the battery end. I ran it through loom that I zip tied to the metal propane pipe. The pipe came right up next to the the 'spring loaded' wiring bundle that goes into the slide for an easy continuation. Finally, I used the hole where the old fridge's copper propane line used to reside to enter the trailer.

One question I do have is regarding ventilation....I've seen some squibs online where some people state it's necessary to block airflow on the existing upper and lower slide sidewall vents if using a 12v fridge. I believe one post I read said that the trailer came from the factory with thin plywood mounted on the inside of the vents.

My Norcold manual states only:

The refrigerator has a built-in vent at the top and clearance at the bottom. Make sure that the flow of air through these vents are not blocked in any way.

Anyone have any knowledge on this?

[JRTJH]

Originally Posted by markcee

I got the old propane/electric fridge out and the new Norcold 12v installed and all seems to be working well. I ended up going directly to the battery with 8 gauge stranded wire, with inline fuse near the battery end. I ran it through loom that I zip tied to the metal propane pipe. The pipe came right up next to the the 'spring loaded' wiring bundle that goes into the slide for an easy continuation. Finally, I used the hole where the old fridge's copper propane line used to reside to enter the trailer.

One question I do have is regarding ventilation....I've seen some squibs online where some people state it's necessary to block airflow on the existing upper and lower slide sidewall vents if using a 12v fridge. I believe one post I read said that the trailer came from the factory with thin plywood mounted on the inside of the vents.

My Norcold manual states only:

The refrigerator has a built-in vent at the top and clearance at the bottom. Make sure that the flow of air through these vents are not blocked in any way.

Anyone have any knowledge on this?

The last line in the instruction manual "Assembling the Enclosure" reads:

"Make sure any exterior vents are blocked"...

Here's the instructions and a link to the manual. The photo is of page 3 of the manual. https://norcold.com/wp-content/uploa...E_20191213.pdf

The "12 volt electric refrigerator" is similar to the one in your house. ALL the venting is into the room, not to the exterior of the house. In your RV, you'll need to block AND INSULATE the existing "gas refrigerator vents". If you "skip this step" you'll have open windows to allow all your HVAC control to escape. In other words, it will be like having two windows open in the trailer while you're trying to cool it in the summer and heat it in the winter.

The part of the instructions you're asking about refers TO THE REFRIGERATOR VENTS, not to the trailer exterior wall vents.....

[markcee]

Originally Posted by JRTJH

The last line in the instruction manual "Assembling the Enclosure" reads:

"Make sure any exterior vents are blocked"...

Here's the instructions and a link to the manual. The photo is of page 3 of the manual. https://norcold.com/wp-content/uploa...E_20191213.pdf

The "12 volt electric refrigerator" is similar to the one in your house. ALL the venting is into the room, not to the exterior of the house. In your RV, you'll need to block AND INSULATE the existing "gas refrigerator vents". If you "skip this step" you'll have open windows to allow all your HVAC control to escape. In other words, it will be like having two windows open in the trailer while you're trying to cool it in the summer and heat it in the winter.

The part of the instructions you're asking about refers TO THE REFRIGERATOR VENTS, not to the trailer exterior wall vents.....

So much for me reading that manual closely...jeez. What a dummy...

Thanks a lot, John. I guess one more step then until it's really ready for use.

When you say block AND insulate, how would you do this?

Here's what the enclosure layout is like:

I left the existing fiberglass insulation in place, it is fully up both sides of the fridge enclosure - fridge is snug against this. I left the existing slide baffle as well, it still left me airspace at the top - this should satisfy the top airflow requirement. The fridge adjustable legs are extended a bit, so there's about an inch of airflow under the fridge.

The enclosure is 24" deep, so not a lot of space remaining between fridge and the pop-off vents.

[JRTJH]

Originally Posted by markcee

So much for me reading that manual closely...jeez. What a dummy...

Thanks a lot, John. I guess one more step then until it's really ready for use.

When you say block AND insulate, how would you do this?

Here's what the enclosure layout is like:

I left the existing fiberglass insulation in place, it is fully up both sides of the fridge enclosure - fridge is snug against this. I left the existing slide baffle as well, it still left me airspace at the top - this should satisfy the top airflow requirement. The fridge adjustable legs are extended a bit, so there's about an inch of airflow under the fridge.

The enclosure is 24" deep, so not a lot of space remaining between fridge and the pop-off vents.

ALL of the Keystone RV models with a "electric compressor driven refrigerator have NO vents in the trailer sidewall. Those refrigerators "vent into the main cabin" and the sidewall behind the refrigerator is intact, insulated with no openings for heat exchange behind the refrigerator to the exterior of the trailer.

If I were installing that type refrigerator in my trailer, I'd leave the plastic vents in place to maintain an "OEM appearance" on the outside of the trailer. On the inside, I'd remove all the baffle structure, fabricate a WATERPROOF/UV resistant covering (maybe a sheet of coroplast cut to fit snuggly) behind the removeable part of the vents. Then I'd fill the remaining space with rigid foam, also cut to fit snuggly, then use expanding foam to fill any gaps that may remain. Then, I'd line the entire exterior wall with a "cut to fit" rigid foam panel to completely seal "and insulate" the exterior wall.

IMO, the fiberglass insulation on the sides of the actual refrigerator serve no purpose with an electric compressor refrigerator. They were there to "contain the heat of the evaporative system gas burner/electric heater chimney" and prevent that heat from migrating into the main cabin of the trailer while that heat was being directed "up to the top vent and out of the trailer. With the compressor driven refrigerator, the top/bottom space OF THE REFRIGERATOR is open to the trailer interior and any insulation on the sides of the refrigerator is "redundant" because "main cabin air" is flowing in the bottom and out around the sides and top of the refrigerator, so insulating the sides serves no advantage to keeping the trailer interior cool..... While it won't "hurt anything" it is "not necessary" to insulate the refrigerator enclosure space like was needed with that space "open to the outside" like it was in the evaporative refrigerator heat chimney....

It's two entirely different refrigerator technologies with two entirely different "venting needs".... Your new refrigerator does not require any "exterior venting" all the heat is blown, by fans, from the actual "refrigerator vents" into the trailer interior. GONE is the heater chimney and GONE is the need to prevent heater chimney venting/insulating requirements.....

[JRTJH]

Here are some "comparison photos" of 2022 Avalanche 295RK trailers, one with the optional gas/electric refrigerator and the "same model trailer" with the residential compressor refrigerator. Take note of the exterior sidewall differences as well as the interior "space around the refrigerator" and "space under the refrigerator" as shown in the only photo I could find quickly. The compressor refrigerator bottom is shown next to the fireplace. With the gas refrigerator, there is a platform under the refrigerator, with the compressor model, the appliance "sits on the trailer floor"....

The "main purpose" of the "complete enclosure around the gas/electric refrigerator" is to seal the cabin space from the potential for propane or carbon monoxide to leak into the cabin and keep all the heat produced by the flame OUTSIDE the cabin. The ENTIRE space is sealed so no airflow or exhaust/heat can penetrate the cabin. This is not required with the compressor driven refrigerator as there is no "health hazard or explosion hazard" present.

[markcee]

Thanks for the detailed info, John!

Much yet to do.

[RollaMo]

Originally Posted by JRTJH

ALL of the Keystone RV models with a "electric compressor driven refrigerator have NO vents in the trailer sidewall. Those refrigerators "vent into the main cabin" and the sidewall behind the refrigerator is intact, insulated with no openings for heat exchange behind the refrigerator to the exterior of the trailer.

If I were installing that type refrigerator in my trailer, I'd leave the plastic vents in place to maintain an "OEM appearance" on the outside of the trailer. On the inside, I'd remove all the baffle structure, fabricate a WATERPROOF/UV resistant covering (maybe a sheet of coroplast cut to fit snuggly) behind the removeable part of the vents. Then I'd fill the remaining space with rigid foam, also cut to fit snuggly, then use expanding foam to fill any gaps that may remain. Then, I'd line the entire exterior wall with a "cut to fit" rigid foam panel to completely seal "and insulate" the exterior wall.

IMO, the fiberglass insulation on the sides of the actual refrigerator serve no purpose with an electric compressor refrigerator. They were there to "contain the heat of the evaporative system gas burner/electric heater chimney" and prevent that heat from migrating into the main cabin of the trailer while that heat was being directed "up to the top vent and out of the trailer. With the compressor driven refrigerator, the top/bottom space OF THE REFRIGERATOR is open to the trailer interior and any insulation on the sides of the refrigerator is "redundant" because "main cabin air" is flowing in the bottom and out around the sides and top of the refrigerator, so insulating the sides serves no advantage to keeping the trailer interior cool..... While it won't "hurt anything" it is "not necessary" to insulate the refrigerator enclosure space like was needed with that space "open to the outside" like it was in the evaporative refrigerator heat chimney....

It's two entirely different refrigerator technologies with two entirely different "venting needs".... Your new refrigerator does not require any "exterior venting" all the heat is blown, by fans, from the actual "refrigerator vents" into the trailer interior. GONE is the heater chimney and GONE is the need to prevent heater chimney venting/insulating requirements.....

Yes

The newer 12v compressor refrigerators do not need any type of outside vent.

Our 2022 24RDS has the 12v refrigerator, and no outside vents.
These refrigerators work pretty much the same as your residential refrigerator in your house (only 12v instead of 120v)

This is our first experience with one, but I have to say we are extremely happy with it.
Gets colder much faster, works just as well in the heat of summer as it does in spring/fall.

[markcee]

I wanted to follow up to this.

We took our first trip, 3 hours away, using the new fridge this week. I left the fridge running during travel and was very pleased to find essentially no loss of battery voltage from start to finish (12.75 to 12.74).

I don't have solar and had read on various forums that many users recommend adding a DC-DC charger as a means to keep the battery topped off during travel, but the 13.7v provided by the charge wire on my truck's 7-pin seemed to do the job.

As a side note, we are super pleased with the performance so far. I blocked the outside trailer wall vent louvers off with HVAC tape from the inside - may do more later, but so far so good. It was awesome to have a fridge compartment cool down to 35* and the freezer to below zero in just a few hours, and remain there!

[rhagfo]

I don’t believe that the draw is all that great, likely will depend on ambient temperature. We install a JC Refrigeration 12 volt compressor cooling unit on our Dometic refrigerator. Has been working great, refer stays at 33 to 35 and freezer near or at zero.

[JRTJH]

There are two types of "12 volt DC" refrigerators. The older ones are "absorption type" which are LPG/120VAC/12VDC which have a heating element that gets hot enough to "boil the ammonia solution"... THEY USE A TREMENDOUS AMOUNT OF BATTERY POWER... So much battery power that we left ours (on a truck camper) on for an hour or so while at McDonalds for lunch, we had a dead battery when we finished lunch.

The newer "compressor driven 12 VDC refrigerators" do not use nearly as much battery power to operate.

So, when referring to "My 12 volt refrigerator", it makes a significant difference whether you have an older 12 volt absorption refrigerator or a newer 12 volt compressor driven refrigerator.

And, yes, both types are still available as new replacements as well as still being used in "antique trailers"....