How much DC current are we talking about? Let's say the house is running an air conditioning load and you are doing laundry and the 'fridge is cycling and you have a few computers on and every light build is turned on and you own a 200-gallon saltwater aquarium. Let's call it 20 KW of use in a really big house. This a very-worst case scenario.
Your DC is set up for 480 volts going into the inverter. 20KVA / 480 is is 41 amps. It is not hard to find a good 60 or 80 amp switch. You can buy one on Amazon.com for $120. Switches that can handle high DC loads are very common. Here is one examle amazon.com/Siemens-HNF362-600-volt-... <https://www.amazon.com/Siemens-HNF362-600-volt-Non-Fused-Switches/dp/B005G953DE/ref=pd_day0_hl_60_1/140-9661733-2175833?_encoding=UTF8&pd_rd_i=B005G953DE&pd_rd_r=a160cb45-7b31-11e9-b1ee-5b598291dad5&pd_rd_w=8QFZM&pd_rd_wg=4YekC&pf_rd_p=ad07871c-e646-4161-82c7-5ed0d4c85b07&pf_rd_r=QQK03FTGP5PQVYKFENBP&psc=1&refRID=QQK03FTGP5PQVYKFENBP> These DC disconnects are a code requirement and are installed by the million, literally. No competent engineer will design a high power low voltage system because you can no longer us wire, you'd n=be into solid copper busses. On Mon, May 20, 2019 at 3:33 AM Erik Christiansen <dva...@internode.on.net> wrote: > On 19.05.19 09:43, Nicklas Karlsson wrote: > > For safety I learned relays fail open circuit while MOSFETs fail short > > circuited, I also experienced MOSFET short circuit failure. Happen to > > know anything more about this? > > I'd only use the MOSFETs to replace relay contacts, and wire a HRC fuse > in series to rupture the fault current. Otherwise, once a DC arc is > established, it could bridge a MOSFET package effortlessly, maintaining > current flow until enough copper flowed away to build a large gap. > > Erik > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
