Shunt Location 2019 TAB 400

JeffroNC

I have a new TAB 400 with factory solar and I want to add a Victron battery monitor. 
Has anybody done it yet? Where should the shunt go?

Verna

My factory installed shunt for the Victron is installed in the middle underbed storage, between the inverter and the batteries. 

Awca12a

I put mine there as well.  Be careful when doing the wiring because the distribution block is live and the battery cut-off switch comes after that block, not before.   This means you will be wiring live unless you want to disassemble everything to get to the battery terminals.   Crazy but true.  The positive and negative nuts are very close and if you aren't careful, they can short if you tilt the socket wrench too much.  You'll see.   

You have to protect the shunt from physical damage inside the storage area so you'll need a box of some type.  I used a GFCI in-use cover and regretted it but needed to get the trailer into motion so I left that in place but purchased a 6.2" x 3.5" x 2.4" Ogrmar junction box from amazon to replace it later.  That's a snow day project. 

I used 1/0 wire to make the short jump from the negative terminal on the distribution block to the negative terminal on the shunt.  Whatever gauge you use, know that the terminal studs are 3/8" which you probably can get at your local auto parts store but certainly won't be at Home Depot.   If you don't already have a crimping tool for a battery size copper lug, your local auto parts store or mechanic may be willing to make that crimp for you.

https://www.amazon.com/gp/product/B0787B1GT3/ref=ppx_od_dt_b_asin_title_s01?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B073Y75H66/ref=ppx_od_dt_b_asin_title_s02?ie=UTF8&psc=1

Assuming you want to put the monitor by the front door where the thermostats are, you can save yourself a bunch of time by routing the grey wire through the conveniently provided black PVC wiring chase that runs from under the sink to the behind the inverter on-off switch.   The non-metallic fiberglass snake works best here.  I still haven't gathered the energy to remove the battery box which involves removing parts of the bed wood structure in order to place the thermostat wire.  Instead, I put it outside the box and if the batteries need to be serviced at some point, I'll move it.

If this is your first time working with the battery monitor, you'll need the settings for the Harris Batteries in the attached PDF.

Lastly, when you drill the hole, double and triple check that you've gotten the correct size hole-saw for what the hole will be after you drill.  If you measure for the inside of the holesaw the hole will be a mite too large because the final hole size will include the width of the saw teeth.

If all this was more than you wanted or needed, then it's here for the next person.


Best

JEB

The battery settings for the Harris batteries to be used in setting up the Victron Battery Monitor are very helpful.  Do you also have recommended settings for the Victron Solar Charge Controller?

JEB

Verna said:

My factory installed shunt for the Victron is installed in the middle underbed storage, between the inverter and the batteries. 

Is the shunt you refer to pictured in this thread?  https://tab-rv.vanillacommunity.com/discussion/8403/what-is-gross-trailer-weight-and-dry-tongue-weight-of-2019-t-b-400-with-fridge-and-microwave/p1

JeffroNC

@Awca12a thank you. It’s exactly what I needed. With your help, it will be like I am doing it for the second time. :-)

JeffroNC

@Awca12a I have some more questions:
Did you happen to take photos of the install? I am a little confused by the wires. I have the factory inverter and solar. It looks like the solar bypasses the cut off switch because the Victron controller shows the battery topped off and in float with the switch off and the unit unplugged.
Can I connect the power leads for the monitor at the junction box as well?

I plan to place a 12v socket in the cubby to run my CPAP. I have a 12v adapter for mine and want to plug it in at night. I noticed that there are unused fuses in the electrical panel and figured I would use one of them to keep the wiring simple. Would I just take the cover off and bind the wires to the sockets on the panel?

Thanks

Awca12a

Take a look at the fuses PDF I wrote but short answer is the solar and inverter bypass the shutoff switch as you mentioned.  

Plenty of photos.  What would you like to see. 

Easy to add a circuit to the 12v side of the panel.   The wiring diagram is in the Electrical PDF I posted.  Take the cover off the top of the converter in the closet and.you can access everything easily.  

JeffroNC

OK
As far as the shunt, maybe just a photo from the top with the bed raised?

Thanks for the tip on adding a circuit. I never would have though of going in from the top. I am hoping the shutoff switch kills the fuse box, right?

J

Awca12a

General advice is to test the circuits you intend to touch before you remove shore power & turn off battery switch and then after.  This tests both the multimeter and your placement of the leads.  Don’t forget the solar is operating and bypassing the shutoff switch.   Any wire you add would need to be stranded and sized correctly.   Might be best if wiring isn’t a strong suit to let your local mechanic to the final hookups. 

JeffroNC

Finally got this done. It was a breeze. Thanks for the help.

[Deleted User]

Do only negative cables attach to the BMV shunt? 

Sharon_is_SAM

Yes.  The tray cable from the negative battery terminal  to the shunt, then the negative lead from the shunt to the junction box.

[Deleted User]

Great! I think I've got it now! One if the pics I found on here had a red cable where I thought it was supposed to be a negative cable and that confused me! Perhaps they just happened to have a red cable on hand.