Hi there,
If have the below Midnite DC disconnect:
http://www.midnitesolar.com/productPhoto.php?product_ID=250&productCatName=Mini%20%20DC%20Disconnect&productCat_ID=8&sortOrder=8&act=p
Has anyone every considered installing a simple on/ off switch in the place of the 250 A breaker? Reason I ask this is that I already have a 250 A breaker in the distribution panel and my 3 battery strings in my bank will all be separately fused. I wonder if there is much of a cost saving in using a switch instead of a breaker in the DC disconnect? If not I can use the 250 amp breaker in the DC disco as an off switch, which is what it was originally planned to be used as, to neutralize any incoming power from the battery bank if I need to get my hands in t the inverter/ distribution panel. Just throwing it out there to get someones thoughts on this?
Thanks
You can use the breaker to switch off the inverter .
I forget what kind of inverter you said you had. On my outback inverter it has contacts that you can put in a remote switch. That does not turn all the power off to the inverter but shuts down the inverter . I have mine with a regular switch and a timer switch in parallel so I could have the inverter shut off automatically after a certain amount of time. You could also use a relay or the contacts on controller to shut off the inverter that way. Using a breaker to shut off an inverter under load is a bit different but they are designed to be able to handle the DC arc that will happen inside of them if they were shutting off the full 250 amps . You can't replace the breaker with a regular switch because the breaker is designed to cut the power automatically on an overload. A switch does not do that. And considering that there are such large wires going to the inverter and through the breaker there is no way you could connect those to a regular switch. Remember the breaker is there to protect the wire from getting hot and melting or starting a fire on an overload. Switches don't do that function.
Larry WT9M
It would help if you could draw out the wiring along with breakers and wire sizes for us to understand how your system is wired up.
Larry