Ventana 3709 Solar upgrade

[Notsotalltexan]

I asked him about that too. He said in my situation, a junction post does the same thing and would suffice. If I know now what I did not know then, I would have requested busbars. Although, the 3/8" posts were 1.25" long and the nuts had a flange only so I did have room for all the lugs on the J-Posts.

On my two battery posts, the 8M - 20 1" bolts came with a lock washer and flat washer which only left about a half inch of threads available. So with cables built with big lugs for 4/0 cable they sold me and Newmar's 3/0 cable lugs and finally the Victron heat sensor connector eyelet on the positive post, I could not start the bolt. So off to Home Depot I went. They had exactly what I needed but I should have gotten two sets since the same thing happened on the negative battery post.

I lost a few hours of sleep last night wondering how I could have missed the cable from the negative junction post to the load side of the shunt. I'll need to make the access point larger between the battery bank compartment to the control board for that 4/0 cable. To do this I'll use a multi-tool. You probably know the wall of the battery compartment has thin metal on 3/4" plywood. I cut access from the control board side and the multitool goes right through the metal with no effort.

I'll post pictures of both compartments today.

Laurent

 

[Richpatty]

Ok. So is the J Post just a bolt to consolidate the cables? I had not heard that term before…

 

[Kevin D Pem]

Ok. So is the J Post just a bolt to consolidate the cables? I had not heard that term before…

Your not alone. Why they economize with terms is beyond me. What ever happened to saying or printing the word, rather than making a conversation out of, oh I mean junction post.

Sorry about the rant!

I use bonding posts all the time. I prefer them over bus bars.

 

[Notsotalltexan]

I’m back here at the RV storage to add a short 4/0 from the Junction Post to load side of the shunt. Right now I have only a 4/0 from the battery connected to the battery side of shunt. As my picture shows I have a 2 gauge from negative battery terminal on charge controller going to load side and chassis ground. I will add a 4/0 from Junction Post to load side.

Here’s my question: Now my J-post has house ground, inverter ground, bi-direction battery isolation cable and I have a 4/0 from negative most battery to the Junction post. Is this last cable incorrect? Maybe this isn’t necessary? Since I already have the negative most terminal attached to the shunt battery side and then adding the jumper from Junction post to shunt load side?

 

[Richpatty]

It’s hard to say from your description. Bottom line: battery ground to one side of shunt…. ALL negavite cables to through other side of shunt. As an example, see how I did it with a bus bar. The cable that disappears into the wall is the ground.

 

[Notsotalltexan]

Okay thank you!! I will remove that negative battery cable to Junction post. I’ll add new 4/0 jumper to load side from Junction post which is my bus bar.

 

[Notsotalltexan]

Okay thank you!! I will remove that negative battery cable to Junction post. I’ll add new 4/0 jumper to load side from Junction post which is my bus bar.

Hey Rich--

I've finished all my solar roof and basement installations and yesterday removed and replaced the battery isolator. I had to add wire to the orange ignition wire as it was a tad too short.

Thanks again for your help.

Laurent

 

[Richpatty]

Great! Glad your project is moving towards completion. I am happy to be have been able to help as I would like to pay it forward for everyone who has helped me.

Rich