dc power is not working properly

[FilterGuy]

nothing connected to #6 tested it and 0 reading i also tested #5 0 reading and b- lug to battery neg 0 reading.

I am still a bit confused. Please look at this diagram:



Do I have A, D & E correct? What is the voltage at B & C?

 

[acdoctor]

Can you meter 12 from B+ to chassis?

 

[FilterGuy]

Measure C without the fuse installed.

 

[FilterGuy]

should the battery neg run through the shunt before connecting to the B- lug???

Correct.

 

[hammerhead22!]

just to clarify the battery already is connected to the bottom lug of the shunt by itself.

i should now connect the neg cable going to the dc lug to the top side of the shunt and then to the lug

 

[FilterGuy]

Looking a little closer, I see the same problem exists with the Solar Charge Controller.



There will be too many lugs on the shunt and the Battery +. I would invest in a set of bus bars to clean that up

 

[hammerhead22!]

A 0V
B 0V
C 12+
D 12+
E 0V

 

[hammerhead22!]

to late today to get a bus bar i will do it first thing in the morning and follow your corrections in the morning.

if i am still having problems i will post tomorrow

thanks for all of your help it is greatly appreciated

 

[FilterGuy]

BTW: The battery arrangement will work but it would be better with one of these two connection schemes:


This helps ensure that the load and charge on each of the batteries is balanced. (There is some debate as to whether this makes a big difference on LiFePO4... but I always try to be careful with balancing the battery connections)

 

[FilterGuy]

A 0V
B 0V
C 12+
D 12+
E 0V

Hmmmm. That totally resets my thinking.

I assume 'C' was measured without the fuse in place. If A is at 0V and C is at 12V then it seems like something is wrong with the fuse board. We need to see the back of that fuse board.

 

[acdoctor]

So I got a IPad so I could read the door. It said 1 through 6 are powered from converter. 7 through 9 are connected to the battery connections B+ as you are calling it. Did you disconnect the converter from the board and if so what did you do with the wires.

 

[FilterGuy]

So I got a IPad so I could read the door. It said 1 through 6 are powered from converter. 7 through 9 are connected to the battery connections B+ as you are calling it. Did you disconnect the converter from the board and if so what did you do with the wires.

Good Catch!!! I totally missed that!!

the cut wires were from the charger

So.... if he disconnected the converter (He calls it charger) then 1 - 6 are no longer connected. That would explain almost everything.

To fix it he needs to jumper between the B+ lug and the positive side of 1-6. The connection should be made where the converter positive used to connect.

What it does not explain is why Fuse #8 is not working.

 

[John Frum]

I've seen this type of panel before.
I think you will find a relay behind the fuse board.

 

[acdoctor]

1) On one of the fuses that is not working, try measuring between the connection and battery negative while the fuse is removed. One of the connections should show 0V and the other should show +12V. My guess is that you will find that there is +12V between the top connection and battery negative (The actual battery negative, not the B- lug on the fuse board.).

2) Measure to see if there is any voltage between the B- lug on the fuse board and the negative of the battery bank. If there is a voltage, there is something wrong with the Negative wire going to the B- Lug.

View attachment 73768

Report the results and we will take it from there.

If I zoom in it appears that question mark is a red and white wire cut

 

[FilterGuy]

I've seen this type of panel before.
I think you will find a relay behind the fuse board.

What does the relay do?

 

[FilterGuy]

If I zoom in it appears that question mark is a red and white wire cut

He said that is from the disconnected charger/converter. What we don't know is wat happened to the other side.

 

[John Frum]

What does the relay do?

Isolates the converter and the battery.
The last time I saw something similar, it was in a truck camper and the rightmost positions(s) on the panel where for the propane sensor which should run all the time.
Also from memory there was no negative busbar so I assume all(most) the loads have a single positive wire and chassis return.

 

[John Frum]

Isolates the converter and the battery.
The last time I saw something similar, it was in a truck camper and the rightmost positions(s) on the panel where for the propane sensor which should run all the time.
Also from memory there was no negative busbar so I assume all(most) the loads have a single positive wire and chassis return.

Actually I think it isolates most of the loads from the battery.
Most of the load positions would only be energized by the converter.

 

[FilterGuy]

Actually I think it isolates most of the loads from the battery.
Most of the load positions would only be energized by the converter.

If I understand the labeling correctly, fuse positions 1-6 are only powered by the converter and 7-9 are 'always on'. A logical use for a relay would be to switch the 'always on' to the converter when it is powered and back to the battery when the converter is not powered..... but I am just speculating.

 

[John Frum]

If I understand the labeling correctly, fuse positions 1-6 are only powered by the converter and 7-9 are 'always on'. A logical use for a relay would be to switch the 'always on' to the converter when it is powered and back to the battery when the converter is not powered..... but I am just speculating.

Yes, sounds right.

In the linked post 2nd picture to the right of the big transformer is the relay I mention.
Maybe @hammerhead22! 's unit has a similar relay.

HELP on wire sizes

Hi new friends. I am getting together a solar system that I will be integrating into my RV's existing electrical system. I am putting the battery, inverter, and charge controller about 12-15 feet from the DC and AC Fuse boxes from the old system. The system consists of 206Ah Sok LiFePO...

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