2021 nuCamp T@B 400 Boondock - Winterproofing instead of Winterizing

krsmes

2021 nuCamp T@B 400 Boondock - Winterproofing instead of Winterizing

Primary components:

* Large pads: https://www.amazon.com/dp/B01MT9EUG9

* Small pads: https://www.amazon.com/dp/B01MUC7XI5

* Govee sensors: https://www.amazon.com/dp/B07R586J37

* 110v heating wire: https://www.amazon.com/dp/B00427COLA

Removing the cover:

The gray water tank:

and drain:

The fresh water tank (and in between):

Fresh water drain and level sensors (this space here is also where I added a Govee Bluetooth temperature monitor):

Large pads installed:

Two small pads on the gray tank— one on the exit pipe and one on the valve outside the frame:

One small pad on the fresh water tank low point (mostly because I had bought a three pack but glad I installed it as it is sufficient on its own most of the time):

Added foil tape:

The orange wire in the previous photo and the taped wire shown below was an additional measure/option to have 110v plug in option to keep everything warm when 110v is available instead of the 12v pads:

Foil bubble wrapped everything (twice, so 4 bubble layers):

Then came the actual insulation— R5(ish) around the entire frame plus sitting between the frame above the corrugated plastic bottom cover (admittedly did not get great pictures of this step):

And all back together again:

Other than the silver wrapping on the drain (and silver bubble visible covering the frame holes) it is impossible to tell anything was changed.  This was a two full day project (one wiring and one insulating) although if I were to have to do it again eliminating the trial-and-error portions it could be done in a day.

This enhancement was much easier than I expected after seeing other posts of the work people had to do in earlier year models to cold-proof their T@Bs.  This 2021 T@B 400 has all the hoses/pipes up in the cabin except for the fresh water tank drain pipe.  The only things below the floor inside the frame are the two tanks and a bit wiring (mostly level sensor wires). 

I don’t have pictures of the wiring but I wired to an open (new) fuse on the electrical center to two switches: one for the large pads and one for the small pads so I can control them separately.  This ended up being a good move because it appears the large pads may have been mostly unnecessary (see temperature tests below).

(I have a separate post on my dry-toilet install which is why there’s no pad on the black water valve — and the black water tank itself is all above the floor in the cabin.)

I am using three Govee Bluetooth temperature sensors (https://www.amazon.com/dp/B07R586J37) to monitor cabin temperature (“in”), tongue box temperature (“out”), and a third one in the underbelly right by the level sensor wires of the fresh water tank behind the insulation (“under”).  Below is log data from over Christmas when it got into the teens and I had the fresh water tank 2/3 full (temperatures in Fahrenheit):

——
Prior to 3:30 both large and small pads on, electric heat, electric fridge

3:30pm 
only small pads on (heat gas, fridge gas)
Battery: 99.2%
Temp: out 18.8, under 48, in 62

4:38pm
Battery: 97.6%
Temp: out 16.2, under 47, in 65
Propane: 97%

4:45pm
small and large pads on, and accent lights

5:40pm
Battery: 92.0% 
Temp: out 14.8, under 47, in 64
Propane: 97%
only small pads on

7:10pm
Battery: 86.3% 
Temp: out 12.8, under 47, in 64
Propane: 89%

Plugged back in and switched fridge to electric

9:30pm
Battery: 89.3% 
Temp: out 12.5, under 47, in 64
Propane: 86%
Switched heat back to electric, set temp to 60
Turned small and large pads on

10:15pm
Battery: 90.6% 
Temp: out 11.3, under 47, in 62
Propane: 86%

12/26

9:00am
Battery: 98.2% 
Temp: out 12.2, under 47, in 52
Propane: 88%

Started driving at 10:15am
Turn only small pads on

12:00noon
Battery: 94% 
Temp: out 22.4, under 49, in 53
——

The above log was mostly a battery level test for myself (standard Boondock solar/battery setup) but the temperatures are relevant to those wondering how well this works, both parked and driving (the last entry).  

It maintained an underbelly temperature in the upper 40s even when it was 11 degrees out over night.  Even switching to just the 3 small pads, without the large tank pads on for several hours, the good insulation did not let the temperature drop.

Very happy with this setup and an quite comfortable taking it out into the cold, with water.

bergger

Wow that's impressive and good job!  Living in such a cold climate as I do I may have to think about that on our 2021 400.  If you get a chance to take some pictures of the electrical switches and fuse set up that'd be great.  The insulation and placement of the pads seems like something I could do but I'm not an expert on adding electrical circuits/fuses.  

krsmes

bergger said:

If you get a chance to take some pictures of the electrical switches and fuse set up that'd be great.  

I'll see what I can do but the electrical was not difficult at all. On my electrical panel there were two unused fuse openings at the bottom. My biggest mistake was using 10 gauge wires when 12 gauge would have been sufficient. 12 would have been easier to work with. I ran the wires through an existing opening where the propane line comes through for the stove (possibly questionable move but I'm ok with it).

12 gauge wire: https://www.amazon.com/dp/B088QFX7QX
Switches: https://www.amazon.com/dp/B07R8KVQWR
Fuses: https://www.amazon.com/dp/B07Q9PL4R6 (not mini)
Connectors: https://www.amazon.com/dp/B07NPGV7G2

krsmes

waterlotus said:

I am so grateful for the awesome job you did writing the runbook here!! Thank you and happy new year!! 

I forgot the important picture...

ChrisFix

Great photo! Love your mod...please let us know how it works once you get some time with it. 

krsmes

ChrisFix said:

Great photo! Love your mod...please let us know how it works once you get some time with it. 

In addition to doing great at home when it was in the single digits at night (underbelly temperature never went below 40), we survived the Texas freeze in February.  We were on the coast south of Houston were it was 10-15 degrees for around 36 hours.  The water had been shut off so all we had to rely on our tanks & pump. I ended up just using the small pads and, again, the temperature underneath never went below 40.

So after using it this over the winter the only "new" info I have is that this was completely overkill even for freezing cold temperatures.  I've never used the two large tank pads, only the three small "elbow" pads that I installed.  And even then that was rare, the insulation itself solved for 90% of the below freezing temperatures -- I only needed to turn on the small pads when it was either below freezing both day and night or it was below freezing and windy.

Putting the Govee Bluetooth temperature sensor under there was a win because I could easily track the temperature changes and see when the pads were needed to be on.

DougH

@krsmes Beautiful installation.  How will you change the batteries on the Govee(s)?  Or how much do you need to take off to access them?

I did something similar on a 320, but ran thermocouple wires everywhere. Not as easy to read the displays.

krsmes

DougH said:

@krsmes Beautiful installation.  How will you change the batteries on the Govee(s)?  Or how much do you need to take off to access them?

I've had the Govees prior to this for other uses and the batteries last over a year.  Just need to drop the bottom cover and slide off one piece of foam insulation.  After I have to change them the first time I'll mod it a bit to make it more accessible through one of the frame's side holes.

Maybe sooner than that as one issue I have had is that my gray tank constantly reads 2/3s full (unless it is full) and I'm pretty sure that i've got some of the sensor wires touching some foil wrap insulation.  It hasn't been a big deal as I can still tell the difference between full and not full but I need to get under there and protect those contacts on the tank.  Sensors for the fresh water tank have been fine.

CJax

@krsmes, this is awesome! Great job! Perhaps a hand-drawn wiring schematic of the fuses and switches would be helpful for folks like @bergger  and myself.

The next evolution of this: has anyone automated something similar such that a thermostat can turn the heating elements on and off instead of manual switching? Especially when the T@B is in storage and on a trickle charge... That would be the full embodiment of winterproofing vs winterizing.

Cheers,

krsmes

If it is in storage I’d assume it would be safer to just winterize. This is setup for usage. 

The large heating pads do only come on at certain temperatures, but I use the switch because I don’t agree with the ranges they have set (comes on too soon at 45 degrees and doesn’t shut off until 68 degrees)

The 110v ac wire I put in would be a good option for plug it in and leave it. 

I meant to do an addendum write up in the wiring but haven’t gotten to it yet. 

The two large pads (4.8a ea) are on one wire with a switch and 10a fuse, and the three small pads are together with a switch and smaller fuse (don’t remember at the moment)

TomInPlymouth

@krsmes Thank you for this.  Like others, I think you're work on the pads is well explained using the photos.  The wiring is a different bag of worms.  (I have the 2021 TAB 400 boondock). A couple of questions as you think about a wiring write-up

• Do I need to disconnect the battery altogether to do any wiring, or does the big red battery off switch do the job? (I'm a rookie on rv mods)
• Where did you end up putting the on-off toggle switches?
• How do you gain access to the converter panel to connect your 12 ga wire to the 2 switches?  It looks like a jungle under there if I pull the drawer out next to my panel.  Any tips for how to manage the wiring path...you tipped us off to using the hole for the propane, but other tight spots?
• If you're using the small pads overnight and not connected to 110...what kind of draw are we talking?  Just trying to see if I'd bother with the 110 electrical wire.

Thanks!  This is a huge help!
Tom
PS: I just have one question on dropping the bottom.  Did any of your self tapping screw heads shear off...mine look almost corroded on a brand new vehicle.  And have you used replacements from Amazon or Home Depot?

Denny16

The Big Red battery switch will disconnect the TaB battery from the trailer circuits.  If you have a BoonDock trailer with solar and an inverter, the inverter and solar panel are not disconnected with the switch, as they are directly wired to the battery. 

cheers

TomInPlymouth

@Denny16 So what does that mean I need to do in order to add a wire to one of the spare openings in the 12 v circuit panel to power the heating pads?

Denny16

Just turn off the battery disconnect switch (big red switch) and you are set to go. 
Same as disconnecting the battery from the power converter.
cheers

TomInPlymouth

Does anyone on this thread have experience adding a wire to the 12v circuit panel?  I'd love to hear what it takes.  Is it as simple as using the connectors (i.e. close the connector on an insulated wire?)  Anyone?

TomInPlymouth

DeletedPost...I've installed the pads a wired it up.  Will describe below

rrcbov

CJax said:

@krsmes, this is awesome! Great job! Perhaps a hand-drawn wiring schematic of the fuses and switches would be helpful for folks like @bergger  and myself.

The next evolution of this: has anyone automated something similar such that a thermostat can turn the heating elements on and off instead of manual switching? Especially when the T@B is in storage and on a trickle charge... That would be the full embodiment of winterproofing vs winterizing.

Cheers,

Would the Victron Cerbo GX do this kind of automation?   

TomInPlymouth

Deleted post

TomInPlymouth

OK, I added heating pads to my 2021 TAB 400 BD.  It's a pretty big unit as these things go.  What that meant to me was that dropping the bottom was a pretty big task.  

1. I put the trailer up on blocks with wheel chocks both sides.
2. The self-drilling screws were pretty corroded even though we didn't drive in the winter other than to bring the trailer home 50 miles.  I bought a pack of 100 hex head self drilling screws used and replaced them all.  Remove carefully.  Even still a few broke off when removing, so have a set of vice grips ready to remove the stubs.  https://www.homedepot.com/p/Everbilt-10-x-3-4-in-Zinc-Plated-Hex-Head-Sheet-Metal-Screw-100-Pack-801262/204275065
3. The bottom is a plastic corrugated sheet that nuCamp has drilled thru when attaching the support channels that hold it in place.  You'll need a punch or awl to refind the holes when re-assembling the bottom...it's big and all the holes need to match up (frame, bottom, support channels).  I'll discuss that later.
4. Once off--the propane hose entry to the cabin keeps it from being moved completely out of the way.  That means you won't roll around on a dolly under this thing...the wheels would damage the corrugated plastic.
5. I was also surprised to see some rust on a frame crossbar.  So I wire brushed and painted with Rust-Oleum inhibiter.  In general there's some cleaning up to do in this step all around the frame and support channels.

OK, with the bottom off--the next step is to clean up the tanks...or the heating pads will not stick.  Alcohol works, but know that the grey water tank (on mine anyway) was not a smooth finish so the pads didn't stick well...also duct tape didn't stick well either.  Ended up using aluminum hvac tape, but I wonder how that will hold up.

I did not end up foil bubble wrapping and rigid insulating these yet...and may not do that.  I want to see what happens with water and condensate.  Will the pads stick in this environment.  And if I seal it up, could I ever find a water problem, should there be one?  Anyway, I didn't do that yet and I'll see how it goes.  

Then comes the wiring.  The important thing to know is that the ground bar is what nuCamp grounds everything 12v to.  So, that's what I did. Here's what the back of the Converter panel and the ground bar looks like.  The power wire from the converter in the wiring diagram comes out the bottom hole.  The ground comes from the bus bar.



Here's the wiring diagram.


To make the circuits from the large pads or the small pads, they're attached in parallel using Lever Nuts.  I used the Wago ones.  Amazon.com: Wago 2 Port (10) 3 Port (10) 5 Port (5) 221 Splicing Connector, Lever-Nut Assortment Pocket Pack for All Wire 12-24 AWG: Industrial & Scientific  Hopefully those are plenty sturdy. 

To run wires along the bottom, I used 3/8" nylon cable clamps from Home Depot.  


So the process is to get both large pads to a 12AWG multi-strand wire--red for power, white goes to the black, and the same for the small pads.  Here's the wire I used. Amazon.com: GS Power 12 Gauge Wire (12 AWG) - Pure Copper Stranded Wire w/Flexible OFC Zip Cord Cable for Car Stereo, Power Amplifier, Audio Speakers, Automotive Trailer - Harness Hookup Wires, 100 ft Red/Black: Home Improvement

The 2 circuits pull thru the propane hose opening readily.



And a partial of the final hookups looks like this.  You can see the power from the converter...split and sent to the center lead of each button (one for the small, one for the large), and all the grounds (large pads, small pads, large pad button gold lead, small pad button gold lead).  There is, of course, also a red wire from the large pads and small pads which go to the outside silver leads of the buttons.



Here's the front of the converter...with the wire attached to a 20 amp fuse.



To drill holes for the buttons, I used a 13/16th Fortner Bit so that the holes were clean and didn't split up the cabinet laminate.  Freud Pb-0055 13/16-Inch Precision Forester Bit - Forstner Bits - Amazon.com

And here's the finished panel with the two buttons mounted on the side.  The buttons work (light up when switched on), nothing blew up, though it's hard to tell if the heater pads are working when it's 94 degrees out, the pads "work" when it's below 48 degrees, and I'm not experienced at reading circuits.  



Anyway, I dove in and perhaps this helps.  And let me know if you see things that I need to fix, I'm going to drop the bottom again after a bit and see how it all looks even though that's a huge PITA.
Tom

Tabbers4Life

Do you know the current draw on this for, say, 10 deg F outside temp? That is, how long will the battery keep it from freezing water pipes if it is overcast?

TomInPlymouth

@Katie8 I don't know the draw.  The pads have a temperature cut off of 48 and until this week the temperature below 48 to even get the pads to draw current.  I am curious as well, though, and when it's cold enough I'll turn them on and see.

I don't anticipate camping in 10 deg F weather...just looking to keep from damage when temperatures drop below freezing during the night.  Hence, I also DID NOT put the rigid insulation in the underbelly.  (I figured that on the Tab 400, with the bottom cover so big and difficult to remove as it is, checking for leaks or other maintenance tasks that might pop up could become harder to do with insulation in under there too.)

Check the comments above, though--the original poster who put rigid insulation on as well only ran the small pads and that kept the underbelly over 40 degrees.

TomInPlymouth

@Katie8 If you've not downloaded the unofficial nuCampT@B 400 Resource guide I would recommend it.  On page 53, he's built a current draw spreadsheet for boondocking.  He lists the current draw of his heating pads (which don't change with how cold it is, just are they on or off) and his total 11 amps when all are on...so you can estimate things from there.  He also states--which may be helpful to you, "You have a maximum 112 Amp-Hours you can draw out of the battery before you need to add more through solar or shore power."

Dutch061

I have been doing research on installing heating pads too, I have sent a PM to the OP and have gotten a reply back, there wasn't any additional information they could update me with beyond their last posted update.

Based on my research so far, this is what I can share. 

1. I have found at least 3 different manufacturers of heating pads

    A. Facon (Amazon)
    B. LaSalle Bristol (E-Trailer)
    C. Ultra Heat (Tier 1 Supplier to RV Industry)

It appears the larger pads all draw around 4 to 5 amps when they power on, duty cycle will be related to ambient temperatures, insulation, wind, etc. 

Facon - mixed reviews on Amazon regarding quality, made in China and have a 1 year warranty.

LaSalle Bristol - E-Trailer advertises a 1 year warranty but LaSalle Bristol advertises a 2 year warranty. Appears to have solid reviews on E-Trailer's website. Origin of manufacture not listed. "Cold room tested to -32 F".

Ultra Heat - Made in the USA, and starting July of 2019 has a "Limited Lifetime Warranty". Specifically state that they prevent freezing to temperatures to -11 F and use a heavier material than others to provide additional protection to the heating element(s) for those open area installations. 

Pricing between LaSalle Bristol and Facon are very similar, Ultra Heat are 2 to 3 times higher priced but USA made and as mentioned Lifetime Warranty. In addition, they are a Tier 1 Supplier to the OEM which is a huge statement.

From my research, I have found that none of the 3 listed above recommend installing any insulation over the top of the pad(s) that have thermostats. It will prevent the thermostat from being able to properly sense the temperature and may also cause an early failure. 

So, what is my decision?

Actually I haven't come to a final decision beyond the fact that I am going to install something. I am probably going to install some Blue Dow Foam insulation around the frame rails and between the underbelly cover and the tanks. Exactly how much and where I don't know because I haven't removed the underbelly cover. 

I can say that in early September we were at 8000 ft. in the Big Horns and the second morning it was 25 degrees when I got up. We had zero issues but then again ambient temperature is only part of the equation on "when will I have a frozen mess". 

I can also say that if I could wave a magic wand, the only thing I would probably change about our 400 BDL is that it was 4 season capable. Not necessarily sub-zero 4 season capable but continued use below freezing. It would be great if NuCamp could offer an option for either a higher R Value insulation package or a 4 Season option. Who knows, maybe they have researched this already and it wouldn't be something that makes sense for them.

Brad

mikesnewjourney

This is an impressive link to aid me in my same attempt at winter travel with our T@B 400 2019.  I made a couple of changes I installed a waterproof junction box and ran three loads 1.  Fresh 2. Waste 3, Grey and am going to place a three position switch panel next to the circuit panel. I noticed the Negative bus bar was over crowded with several neg lead going under one lug, So I purchased a 24 lugged ground bar at home depot GE and replaced the 8 bus bar to instead of using the Wagos which I use all the time now instead of wire nuts.  Thank you again for your great work.  Mike

mikesnewjourney

Good morning great work on this.  Just curious about the outdoor shower ??  Did you insulate this or sense it is kind of inside the trailer may be ok ??  Thanks again for your great work.    mikesnewjourney Tacoma 2016 T@B 400 2019.  

krsmes

mikesnewjourney said:

Good morning great work on this.  Just curious about the outdoor shower ??  Did you insulate this or sense it is kind of inside the trailer may be ok ??  Thanks again for your great work.    mikesnewjourney Tacoma 2016 T@B 400 2019.  

I’ve had no issues with the outdoor shower (obviously not keeping any water in the shower hose itself) or control panel.  That is all “inside” and right next to the the ALDE — there is a lot of excess heat right there (I’ve put a temperature sensor near the ALDE and that little cubbie area gets to >100F when the ALDE is running on propane— I’ve actually thinly insulated under the top bed board to try and keep the bed from getting so hot).   I’ve considered adding insulation to the cover to help on cold drive days when the ALDE is off but haven’t run into any problems yet so keep putting it off.

I also added a ground lug bar (since the original write up) as I’ve done a lot of additional electrical (re)work in the past year (solar, lithium, heavier duty power to the front area of the trailer, etc)

3 years now. Still serving me well.   I had to redo the drain valve heaters and drain valve itself due to some damage while off-roading.   I make use of the 110 plug in option mentioned in the original post more than I expected to — makes it real easy to not worry about it when parked for a while and not out winter boondocking.

slmarchap

krsmes said:

  I make use of the 110 plug in option mentioned in the original post more than I expected to — makes it real easy to not worry about it when parked for a while and not out winter boondocking.

Hi krsmes and Happy New Year!

I can't tell you how much your time and effort in communicating your "winter-proofing" of your 2021 400BL is appreciated!  We have a 2020 and love it!  I know that some reconfiguration happened between models, but I am very much looking forward to replicating your modifications in the spring.  I am also very interested in any additional information you could give regarding the 110 plug in.
For example:  Was 30' enough to run along all of the tanks or did you only run it along the fresh water tank?
We live in Colorado and this would be GREAT to just "plug in" at home between outings!

Thanks again!

krsmes

slmarchap said: Was 30' enough to run along all of the tanks or did you only run it along only the fresh water tank? 

You could even go longer.  I started it on the fresh water drain line, ran it across the bottom of fresh water tank (towards the door side of the trailer), back across the gray tank, and then ended it wrapping around the gray/black drain. Any extra just add some zigzags under the tanks. 

Best of luck. 

slmarchap

Thanks so much krsmes!  Happy Camping!