โAug-08-2018 12:10 PM
โAug-17-2018 08:19 AM
pianotuna wrote:
I believe you are over thinking this.
โAug-16-2018 08:53 PM
LipschitzWrath wrote:
Another question. Would it be advisable to go with Type I (cycling) or Type II (modified reset) circuit breakers in this application. My inclination is to say Type II, but I thought I'd ask.
Seems like the breaker constantly cycling on and off (Type I) would be a bad idea.
โAug-16-2018 08:45 PM
LipschitzWrath wrote:
The {old} converter outlet wire quickly disappeard behind a wall. I'm presuming that this wire also runs to the DC panel. There is no visible circuit protection on this wire. I don't see anything at the DC panel either. This leads me to believe this wire is not protected at all (factory setup). Thus, when you are powering your DC off the converter, the feed to the DC panel has no overcurrent protection. When running off the battery, you do.
Here's is the electrical path when running off converter:
Converter output --> DC Panel --> Circuit Breaker --> Battery bank
When running off battery:
Battery bank --> circuit breaker --> DC panel (conv output wire would also be energized, but irrelevant here)
The cabling upgrades I made did not modify this. BFL is spot on - before AND after my wiring upgrades, there is no circuit protection to the DC panel when running off the converter.
I intend to fix this.
This all assumes there is no hidden breaker or fuse stashed somewhere on the converter output that I have yet to find.
โAug-16-2018 02:44 PM
โAug-16-2018 02:15 PM
LipschitzWrath wrote:
Another question. Would it be advisable to go with Type I (cycling) or Type II (modified reset) circuit breakers in this application. My inclination is to say Type II, but I thought I'd ask.
Seems like the breaker constantly cycling on and off (Type I) would be a bad idea.
โAug-16-2018 02:06 PM
โAug-16-2018 12:27 PM
โAug-16-2018 12:20 PM
BFL13 wrote:
You don't need a fuse on the PV to controller line but it is handy to have some sort of switch for disconnecting that line before you disconnect the controller-battery line for any reason. Some guys use a fuse there so they can just pull it as their on/off switch.
โAug-16-2018 12:18 PM
pianotuna wrote:
There likely is an automatic circuit breaker in the positive feed near the battery bank.
Solar controllers are often wired directly to the battery bank, hence the need for a fuse near the battery bank. I tend to class these as catastrophic failure devices, so a fuse is "faster" protection than a breaker.
โAug-16-2018 12:16 PM
โAug-16-2018 11:56 AM
BFL13 wrote:
I found this a great help wrt fusing. See the diagrams for how each wire gets its own size fuse etc when using buss bars.
http://www.bcae1.com/fuses.htm
You can think of your "junction" collection points as being buss bars for this purpose. Also note the idea of the single fat wire out one side carries the total amps of the branch wires. That also applies to the neg wires. The shunt will need that--collection of thin wires at one end, and a fat wire (two in your case) out the other end to the battery.
The solar controller's pos wire to battery should have a fuse on it already being a kit? Anyway, same thing-- fuse for its own ampacity as a "branch".
Your idea to make a drawing of your set- up's wiring is a good one. You can then see better what is going on for "branches" and all that
โAug-16-2018 09:33 AM
LipschitzWrath wrote:
A couple things to add.
My second method above (2x 40A breakers) makes no sense, at least if you're powering off the converter. The converter breaker is going to open before you reach the ampacity required to open either feed breaker, unless the battery is somehow "supplementing" the DC load.
โAug-16-2018 08:44 AM
โAug-16-2018 08:31 AM