Batteries gone ...

[GeorgeRa]

Originally Posted by themexicandoctor

...............

My problem is this fridge that just runs & runs & Novakool thinks if it isn't the wrong gauge wire, its an issue with the negative side of my DC System.

.......................

Congratulation on your purchase, some increase in battery capacity should help.

So, the issue is that your fridge is running constantly, correct?

If the voltage is too low due to wire or ground there is a simple test, get a multimeter and measure the voltage at the refrigerator. It should be 12V or above. DC wire for 3-way fridge is around 8-10 gauge, if this wire was used for the compressor fridge the positive side should be OK. Ground could be checked with ohmmeter.
https://www.harborfreight.com/dm300-...ter-64018.html

Constantly running fridge could be for multiple reasons:
1. It is too hot
2. Door is not properly sealed
3. Air flow on the back side is insufficient
4. A capillary electromechanical thermostat failed – warranty
5. Low voltage, I don’t know. See Danfoss spec

[avanti]

Originally Posted by GeorgeRa

3. Air flow on the back side is insufficient

This would be my first guess.
Are you confident with your setup in this regard?

[hbn7hj]

Originally Posted by hbn7hj

I have a compressor conversion I have not installed yet, four 100ah lithium batteries and 225ah of FLA which hopefully will do the job.

For those of you that do not know it a compressor conversion is not available for the RM2354 size fridges. No room for the compressor between the fridge and wall.

Those of us in Phoenix must opt for the larger Danfoss compressor in the Novacool or other brand fridges. The issue is heat transfer. For a given heat transfer the larger compressor will run less making the larger current draw less of an issue on cooler days.

Appreciate MD being forthright about making it work. It is all about ventilation and amp-hours. I’m looking forward to a compressor fridge but not the amp-hour struggle with 100 watts of solar. For me it will take 200ah of lithium and a daily short generator run.

[hbn7hj]

Originally Posted by GallenH

H: BTW: I noticed that your post still describes a hybrid system? Are your 400AH of lithium going to have the function of charging the 225 FLA which in turn will be the batteries going to the load?

Yes, hybrid.
The load is switched between FLA and lithium as needed. On low power days I use lithium alone. The generator only charges the FLA when the lithium is being charged. It is a fool’s errand to charge an FLA to 100% with the generator. The load is switched to the lithium/solar if it is also charging the FLA.

The lithium charging rate is 100 amps. It should be 200 amps and we are working on that. Generator runs at 200 amps would be short.

Both battery banks are at 100% at sunset, daily. This is easily done. This is for the class C whose electrical system is designed to sit, not drive. The FLA is there to make use of the non temperature controlled battery tray for extra capacity and interface with the alternator.

The class B is more charging capable. The alternator can charge both the lithium and FLA. The lithium can charge the FLA. With 100 watts of solar, 100ah of FLA, and 100ah of lithium it would be a daily effort to support a compressor fridge. If I get there I’ll add another lithium and see how that works.

[eric1514]

Originally Posted by GeorgeRa

Constantly running fridge could be for multiple reasons:
1. It is too hot

That's what I'm going with. He said it was 116 out there. There is no "cooling" air to remove heat from the back.

Secondly, my NovaKool was not all that well built and insulated. The front door always felt cold.

[hbn7hj]

I would vote for too small of compressor for the heat encountered. Most of us would never travel in heat like that and it is probably temporary for MD so find some shore power and let it pass.

As the schematic shows there is a way to increase compressor speed. I will install a variable resister to give it a kick in the pants when needed.

https://www.amazon.com/Taiss-Potenti.../dp/B07DKCBVTP

[booster]

Originally Posted by hbn7hj

I would vote for too small of compressor for the heat encountered. Most of us would never travel in heat like that and it is probably temporary for MD so find some shore power and let it pass.

As the schematic shows there is a way to increase compressor speed. I will install a variable resister to give it a kick in the pants when needed.

https://www.amazon.com/Taiss-Potenti.../dp/B07DKCBVTP

We have had a home made variable speed switch on ours since the beginning, as I saw it it the tech documents when researching. I think I used 5 resistors on a multipostion rotary switch. Works well, but we have never encounter heat where it couldn't keep up in low speed. 100* is the mos we have seen, with the all day sun on the frig side.

[avanti]

It is worth noting that the theoretically most efficient way to run a cooling system is to arrange for it to be sized such that it just barely runs continuously. The reason is that starting up a compressor takes significantly more power than running one. This is why installing an oversized A/C is considered bad form in the HVAC world. A huge A/C that runs infrequently is horribly inefficient. It is also less effective as a dehumidifier, since it can't remove moisture when it isn't running. So, having an A/C that never turns off is not in itself a bad thing.

The problem, of course, is that it is very difficult to follow this advice in a situation in which the ambient temperature fluctuates wildly. You tend to either be in a situation in which you are running continuously and not keeping up, or shutting down due to excessive cooling.

A sufficiently agile variable-capacity compressor could address this problem: You would use temperature feedback to continuously modulate an always-running compressor, rather than a Bang-Bang on/off thermostat. Some systems attempt to approximate this. I really don't know how well they do or what the practical difficulties turn out to be.

[Rocinante]

Once you have the electrical system operational again, I urge you to use the best climate control system in your van: the wheels.

[themexicandoctor]

Originally Posted by GeorgeRa

Congratulation on your purchase, some increase in battery capacity should help.

So, the issue is that your fridge is running constantly, correct?

If the voltage is too low due to wire or ground there is a simple test, get a multimeter and measure the voltage at the refrigerator. It should be 12V or above. DC wire for 3-way fridge is around 8-10 gauge, if this wire was used for the compressor fridge the positive side should be OK. Ground could be checked with ohmmeter.
https://www.harborfreight.com/dm300-...ter-64018.html

Constantly running fridge could be for multiple reasons:
1. It is too hot
2. Door is not properly sealed
3. Air flow on the back side is insufficient
4. A capillary electromechanical thermostat failed – warranty
5. Low voltage, I don’t know. See Danfoss spec

Didn't realize there was a page 3, Thank You Gentlemen, for a few hours I thought I was going to be brainstorming this by myself.

I have a Multimeter but I think seeing the original installer will help me, especially if, its an issue with the wire gauge or "something is stealing the power on my negative side .." according to the Head Engineer at Novakool.

It is too Hot.

This is unusual weather for LA.

But it was still using quite a few amps overnight before the hrateave to the point that around 12am, 1 or 2am I would be awoken by a "low voltage alarm" which would cause me to get up & have to idle the motor for 15 minutes.

As it is, I have been connected to the dhore power (a very rare thing for me), have been running the ac most of the night, my Magnum says FULL BATTERY & still, the Fridge is working non stop because I can hear it.

(I don't mind the sound - RV's are not noiseproof).

As per the photo from 6pm last night, I am parked behind my tire installer waiting for a new HydroBoost Brake Master Cylinder which has been going south - as you can see there isn't a lot of room around the fridge area because of some trash bins.

Here are the photos previous to install, there is at least 6inches between the rear of the fridge & the R3800 which is 3 inches less in depth than the R4500 & about 5inches less than the original Dometic RM2354.

That should be, according to Danfoss, prior to the install, sufficient air venting at the bottom & at the top.

I did ask them as to whether or not I should add an extractor fan, not wired to the board, on a separate switch to which they havent be enthusiastic yet as to supplying me with an affirmative answer until I get the other questions answered first.

[themexicandoctor]

I will add, maybe its just I but whereas before I thought that I always saw the "Novakool Fan", it was positioned to blow over the condenser cooling it down but on my unit, it blows on the back of the lower fridhe - I asked Novakool about it the day of unboxing & they said it was an improved design - any opinions?

[themexicandoctor]

Originally Posted by avanti

This would be my first guess.
Are you confident with your setup in this regard?

I am only in that when I sent pictures & dimensions to Danfoss, they felt there was more than enough.

Again, the truck has had the ac via shore power for over 12 hours & its exactly 89.1 in the front of the truck now but it was 71% at 7.30am.

And whenever I wake up, every 90 minutes, the fridge was on & has been on all morning since being fully awake.

And the fridge side is shaded.

[avanti]

The way to determine whether to add an exhaust fan is to measure the temperature in the area behind the fridge. If it routinely gets hot back there, a fan will help.

If you do add one, don't install a manual switch. Get a temperature-controlled fan speed control from eBay (very cheap). That way, the fan will be modulated and will be much quieter. Also note that NovaKool controls often have an "external fan control" output, which will turn on along with the compressor.

[GeorgeRa]

I can't see where cooling air flows, is fan pushing air down?, hot air goes up so is the fan preventing convection flow?

[themexicandoctor]

Originally Posted by hbn7hj

For those of you that do not know it a compressor conversion is not available for the RM2354 size fridges. No room for the compressor between the fridge and wall.

Those of us in Phoenix must opt for the larger Danfoss compressor in the Novacool or other brand fridges. The issue is heat transfer. For a given heat transfer the larger compressor will run less making the larger current draw less of an issue on cooler days.

Appreciate MD being forthright about making it work. It is all about ventilation and amp-hours. I’m looking forward to a compressor fridge but not the amp-hour struggle with 100 watts of solar. For me it will take 200ah of lithium and a daily short generator run.

I disagree* on this point only because I did research for several weeks here & looked at everything from;

*I have a 2005 uniton a 2004 Chassis, yours might be different

The Novakool R3800 & R4500 (EXACT FIT but 1 inch shorter on both models than the Dometic RM2354 & the R4500 being 3 inches deeper than the R3800 and starts at 4.4amps versus 2.2).

To building out the cabinetry & putting in a Isotherm 85 like Booster has for many years

Or sliding in a Isotherm Cruise 100 Classic very popular for many at Sportsmobile who order 20 a month (this slides in perfectly but it is top vented cooling fans seemed inefficient in a van that even with the Fantastic Van running at #1 heats up to 105% easily in the rear lounge alone.

I looked at putting a Vitrifrigo but they all require breaking down the center cabinet wall that separates the Roadtrek 190 Versatile kitchen cabinetry from the fridge area to gain the 1/2-3/4 inches in width.

I even looked at the Happy Smiling Faces on the brochures of the latest Dometic & Norcold models sitting around BBQs drinking cold drinks (I suspect these were owners on Day 1, only).

And then after I placed the order & waited 6 weeks for delivery, I got buyers remorse and starting investigating again, in depth, Chest Freezers by Engel & everyone else until I realised that only Engel, National Luna & to a lesser extent ARB, make viable units that have a track record of decades & performance figures you can rely.

Moreover, unless you are willing to cannibalize part of your existing Roadtrek set up ie; putting the unit in your hallway or behind the seat, these units are designed to be built around not added to a Roadtrek.

The only unit that is a Fridge Freezer is the Engel MT45 ($1100), which would work but would have to be placed lengthwise in the existing Roadtrek Fridge Cabinetry of which there is 23 inches depth,the unit is 26 inches long & the only viable slide is 28 inches ($300-450), which means even fully locked into your Roadtrek cabinet, 5 inches would extend into the shower area & to open the fridge you would have to slide it out into that shower area

I was willing to pay $1500 for the privilege & efficiency but not by sacrificing the shower/hallway area.

If like MSNOMER I was building out a coach, the Engel or National Luna would be my #1 choice.

I looked at everything for weeks including Truckfridge (made by Isotherm but 30% less in pricing but they only sell the smaller units - by the way, Isotherm & Vitrifrigo are the same company), & I believe that while they have much more sophisticated cooling techology than the Novakool, Novakool's simple design & Soviet Era looking finishes sealed the deal for me.

By the way, all the installers I spoke with, after looking at the Roadtrek set up, suggested the Novakool because of the natural chimney effect of the existing venting.
.

[themexicandoctor]

Appreciate MD being forthright about making it work. It is all about ventilation and amp-hours. I’m looking forward to a compressor fridge but not the amp-hour struggle with 100 watts of solar. For me it will take 200ah of lithium and a daily short generator run.[/QUOTE]


And I appreciate your acknowledgement as to my openess & honesty, if it was a Human Being I would already have an answer in seconds but this has me stumped.

These forums are based on integrity.

Novakool is an excellent choice.

Thier Sales & Customer service have been excellent pre-sale also as I had many questions.

My challenge is with a limited 250 watt Solar set up & the 8 months a year of 75% weather, I need all the wiggle room I can get.

GeorgeRA might also be right about a failed part but even before the Heatwave, it was using a lot of power.

I rarely, if ever get anywhere near Shore Power so being able to ameliorate any charging deficiencies never hapens (this last round of Lifeline Batteries jave been babysat until the arrival of the fridge & have still performed flawlessly but the solar cannot keep up).

[themexicandoctor]

Originally Posted by avanti

The way to determine whether to add an exhaust fan is to measure the temperature in the area behind the fridge. If it routinely gets hot back there, a fan will help.

If you do add one, don't install a manual switch. Get a temperature-controlled fan speed control from eBay (very cheap). That way, the fan will be modulated and will be much quieter. Also note that NovaKool controls often have an "external fan control" output, which will turn on along with the compressor.

Do you have a link as to what you recommend if in fact this is also part of the issue? I will repeat it was running all night even with the ac on.

[themexicandoctor]

Originally Posted by hbn7hj

For those of you that do not know it a compressor conversion is not available for the RM2354 size fridges. No room for the compressor between the fridge and wall.

Those of us in Phoenix must opt for the larger Danfoss compressor in the Novacool or other brand fridges. The issue is heat transfer. For a given heat transfer the larger compressor will run less making the larger current draw less of an issue on cooler days.

Appreciate MD being forthright about making it work. It is all about ventilation and amp-hours. I’m looking forward to a compressor fridge but not the amp-hour struggle with 100 watts of solar. For me it will take 200ah of lithium and a daily short generator run.

Of this, I am certain unless you were to go with the Engel MT45 Combination unit - ridiculously low plus the efficiency of the chest opening rather than the upright door.

MSNOMER has the ultimate build out even though I always wondered about heat production in her closed but vented unit - but Engels also produce very little heat.

By the way, u got to know the Chinese Distributor for ICECO in the USA & he accidentally slipped up & admitted that "Yes, their units do NOT run as per the stated amp draw & if it is a combination unit as in a fridge freezer, they can easily triple or more that stated amp draw trying to keep up with two different cooling zones.

[themexicandoctor]

Originally Posted by Rocinante

Once you have the electrical system operational again, I urge you to use the best climate control system in your van: the wheels.

I hear you BUT.

It feels to me that now my RV Lifestyle is based around keeping my DC Fridge happy.

While I drive at least 30 minutes everyday, ome days much more,, being in an Urban setting like Los Angeles, I like to relax & once I get to the bottom of this issue, I intend to.

Driving to keep the batteries topped up & air zipping past the vent walls is not what I envisioned as Happiness prior to the new fridge.

[themexicandoctor]

I should add this statement from the Novakool Head Engineer;

Something is wrong, yes we can see that you used 52amp hours in a 12 hour period but from an Engineer's viewpoint who works with these units everyday, even at 2.5amps per hour, multiplied by 12 hours, this is only 30amp hours.

Something is wrong, could be the unit having to start frequently which uses more amps, etc.