Planning power system: input needed.

[ibike]

Aaaand I'm back. Got wrapped up in some more pressing projects and this one got put on the back burner. I revisited all my notes and previous sketches and started to get lost in the weeds.

I went back to the drawing board and put together a diagram of just the fundamental components. Power sources, charging, storage and monitoring. Once I get all this nailed down it should be a little less daunting to tie in the accessoires I want to power.

I've been using a new website at work called LucidCharts so I decided to give it a whirl for this project. Overall pretty happy with it.

One question I did have, power for my Victron monitor. I have the power connection to the shunt drawn on the battery side of my house disconnect switch, meaning the monitor will always have power.

I have read of occurrences of these monitors with the Bluetooth functionality built in running down the house battery on systems that aren't recharged frequently. I purposely bought the older version that is sans Bluetooth. My monitor is just inside my side barn doors, I can never envision a time I would need the wireless function (I can always add the module if that changes)

That being said, should I have any concern for the monitor being on full time? I only use the van on weekends, and when it's sitting the power system will be "dark". All batteries and solar disconnected.

[ibike]

I spent some time in the garage this afternoon milling over my "power board". The shunt for the battery monitor was a new addition, I decided to rearrange a few things. I opted to use brown to represent the ground cable for visibility.

Also, just put in an order with CE Auto Electric (local PHX company, check them out) for all my 4AWG stuff plus a few 0WG things I want to change.

I know Scalf does not approve of my horizontal battery charger so I've already got some plans in the works for active cooling in the wheel well box that houses my power center.

[Scalf77]

Not sure why you want the shunt there, I would make it the most direct line from ground bus bar to battery. Also you have placed it in the exit path of KISAE DMT-1250 which will be preheating it. Shunt's in general generate heat, so I wouldn't put it in the path an existing heat source or at the top of the box.

I don't see, the reason why you are intent on installing the KISAE horizontally, looks like you could go vertically pretty easily on that board. It is not just my recommendation, but also in the installation manual

I spent over twenty years doing thermal testing on computer products.

-greg

[ibike]

Originally Posted by Scalf77

Not sure why you want the shunt there, I would make it the most direct line from ground bus bar to battery. Also you have placed it in the exit path of KISAE DMT-1250 which will be preheating it. Shunt's in general generate heat, so I wouldn't put it in the path an existing heat source or at the top of the box.

I don't see, the reason why you are intent on installing the KISAE horizontally, looks like you could go vertically pretty easily on that board. It is not just my recommendation, but also in the installation manual

I spent over twenty years doing thermal testing on computer products.

-greg

I placed the parts based off proximity to the devices they would be connecting to, cable bend radius etc. That charger is going to be receiving four 4awg cables and two 10awg just by itself. I’m using heavy wall marine lugs for all my power and ground connections. I’m concerned there won’t be space for cable entry/exit and adequate strain relief if I spin the charger 90 degrees. I’ll take a look and see if I can make it work that way though.

For the shunt, I couldn’t find a good way to orient it by the bus bar so I chose some unused real estate by one of the grommets. The power board has stand offs the float it off the wall of the van, essentially creating a chase behind it. It’ll allow me to pass interconnect cables in and out of the board and prevent creating a spaghetti mess on the visible area. I may be able to flip the shunt 180 and put it at the bottom of the board directly opposite of where it is now.

Any input in regards to the Victron monitor power connection, pre or post battery disconnect?

Thanks for the input, much appreciated.

[Scalf77]

In general I like to wire in a always on circuit, this I usually attach the battery monitors, CO and Propane sensors and such. This is separate from the main disconnect switch. If I was putting the RV away for the winter I would through all the disconnects, for just a week I would just leave the always on.

The Victron specification says that it uses less 0.004 amps, without back light. So I would say you are good on the battery side. Make the fuse somewhat accessible and you have your long term storage solution.

Also another way of looking at the battery disconnect is instead as a load disconnect. I usually put a main disconnect on the loads, that way solar or any other charging resource could remain attached to the battery. This gives you more flexibility in storage solutions.

The attachments are a pain in the ass, I agree . One thing you could look at is using just one larger ground wire for the input/output , and run solar ground to bus bar. The grounds are all attached inside the DMT-1250 anyway, a real pain in the ass, if you are trying to measure current on the ground path. Also you could look at smaller wire from the from the fuse block and the ground bus if you keep them close. The length is short , voltage drop would be minimized.

-greg

[ibike]

OK! I think I figured it out. I got creative and figured out a way to stack the amp and DSP, gonna make some brackets out of aluminum flat bar. I actually made space for a 1000w inverter in the process. Going to add two new grommets to the panel to accommodate new device locations.

I added some notes to show what goes where. My plan is to put some 1.25" 2-hole PVC pipe straps on the back of the panel to help keep cabling in place as it moves from one grommet to another.

I re-read some posts and was looking at one specifically about adding a disconnect for the load side. I already have the power source disconnects covered. Would I just need to intercept the power cable that connects the midi fuse and fuse distribution block?

[ibike]

Oh and for the connection from the shunt to the ground bus, would it be plausible to just make a jumper out of some copper flat bar shaped and drilled to fit since the terminals are so close together? Something similar to this:

[Scalf77]

Yes a copper bus bar would be great, I have even used Blue Sea 9160 Link Bus ACR . The PVC straps will work I generally use mounting cable ties.

You are going to need a fuse for inverter, it is possible your main battery fuse, shown on one of your drawings would work. But, that would generally have to handle inverter and fuse block, which means you probably need independent fuses for both of those devices. The Midi fuse block you have is just for the output of DMT-1250, it does not cover the path for the house battery. If that makes sense.

I like the new lay out.

-greg

[ibike]

Originally Posted by Scalf77

Yes a copper bus bar would be great, I have even used Blue Sea 9160 Link Bus ACR . The PVC straps will work I generally use mounting cable ties.

You are going to need a fuse for inverter, it is possible your main battery fuse, shown on one of your drawings would work. But, that would generally have to handle inverter and fuse block, which means you probably need independent fuses for both of those devices. The Midi fuse block you have is just for the output of DMT-1250, it does not cover the path for the house battery. If that makes sense.

I like the new lay out.

-greg

For the inverter, would another midi fuse holder be adequate? I marked a proposed location it would fit on the photo attached

[Scalf77]

You would need to check the installation manual, most inverter companies require a Class T Fuse. This is what I generally install.


-greg