Wiring inverters

[David Sproul]

I am wiring 2 more inverters into my system to give me a total of 6. Currently have 4 in parallel and will be splitting them into 2 sets of 3. Question is....Do I need when have all the wires the same lengths across all the sets or just consistent within the set or does any of it matter? I am not looking at long runs and the differences in the lengths of the wires would be inches.

 

[timselectric]

Battery wires to each inverter, need to be the same length as every other inverter. Those are the only wires that matter.

 

[timselectric]

Paralleled inverters won't work unless they are connected to the same battery bank. If the wires are different lengths, it creates a voltage difference. Which makes the inverters think that they are not connected to the same battery.

 

[Bud Martin]

I am wiring 2 more inverters into my system to give me a total of 6. Currently have 4 in parallel and will be splitting them into 2 sets of 3. Question is....Do I need when have all the wires the same lengths across all the sets or just consistent within the set or does any of it matter? I am not looking at long runs and the differences in the lengths of the wires would be inches.

Are you talking about connecting 6 inverters (basically 6 dc loads) to the same battery bank, and each inverter output will supply power to individual AC loads?
If that is the case then the the wire length will not have effect of interaction between each inverter, the one with longer/smaller wire gauge DC wires will just have more Voltage drops on the wires so less Voltage at the DC Input of the inverter.

 

[David Sproul]

I was thinking to connect the bus bars together as they are now with the 4 inverters in parallel. I currently have 4 batteries and 4 inverters and will be adding 2 more inverters this weekend. Will be adding 4 more batteries this summer so will be changing the configuration at that point when their forever home is constructed.

 

[David Sproul]

Paralleled inverters won't work unless they are connected to the same battery bank. If the wires are different lengths, it creates a voltage difference. Which makes the inverters think that they are not connected to the same battery.

They will be to the same battery bank. The bus bars are connected currently with the 4 inverters and 4 batteries. So I am going to run 3 inverters to 1 bus bar and 3 to the other while then connecting both bus bars together with a jumper...same configuration (for the bus bars) as now but just using 4 inverters.

 

[timselectric]

If they are true paralleled. (With parallel communication cables) they have to see the same battery voltage. 1 or 2 inches may not matter. 12 inches, probably will. You'll know for sure, if you get errors.

 

[WYtreasure]

They will be to the same battery bank. The bus bars are connected currently with the 4 inverters and 4 batteries. So I am going to run 3 inverters to 1 bus bar and 3 to the other while then connecting both bus bars together with a jumper...same configuration (for the bus bars) as now but just using 4 inverters.

Welcome to the show David.

A picture of your setup will make it easy for folks to understand what you already have.

 

[David Sproul]

If they are true paralleled. (With parallel communication cables) they have to see the same battery voltage. 1 or 2 inches may not matter. 12 inches, probably will. You'll know for sure, if you get errors.

The battery cables are the same lengths to the bus bars but the wires from the inverters to the bus bars will or can be different lengths

 

[David Sproul]

Welcome to the show David.

A picture of your setup will make it easy for folks to understand what you already have.

For the moment it’s a spaghetti of wires crossing while they are in their temporary home. Once the garage is built it will be moved, expanded and cleaned up. I did t want to cut and shorten too many primary wires until finished as they are very expensive lately.

 

[timselectric]

The battery cables are the same lengths to the bus bars but the wires from the inverters to the bus bars will or can be different lengths

Not good

 

[David Sproul]

Not good

Not good? Which part?

 

[timselectric]

Not good? Which part?

" but the wires from the inverters to the bus bars will or can be different lengths"

 

[David Sproul]

So those too have to be the same lengths?

 

[timselectric]

Anything wired in parallel, should be done with same length wires. (Inverters, batteries, whatever else)

 

[David Sproul]

Thank you.

 

[Bud Martin]

Anything wired in parallel, should be done with same length wires. (Inverters, batteries, whatever else)

Why would that matter?
I.E. You may have low DC Voltage LED lights 10 feet away from battery, or any other loads which they are all in parallel since they are connected to the batteries.
Or your car wiring, you have lights in the front, lights in the back, lights and other electronics in the cabin.
Or your house wiring, all the loads are basically in parallel.

 

[timselectric]

Those are individual loads.
Not in parallel.

 

[Bud Martin]

Those are individual loads.
Not in parallel.

?????

 

[timselectric]

?????

If Inverters are wired in parallel (using parallel communications cables). The wire lengths need to be the same, so that the Inverters see the same voltage (resistance in wires create voltage drop, increasing with length). Different lengths, will have different resistance (and voltage).
If batteries are wired in parallel, the same principle applies. The batteries won't be balanced, if they are connected with different lengths from each other.

Individual loads do not require to be balanced with each other.