SW 4048 Inverter Problem - Transfer Switch Remedy?

muirhousemuirhouse Solar Expert Posts: 82 ✭✭
So, I am not tied to grid, and I have a Trace/Xantrex AC Disconect Transfer Switch wired in never needed to use. Trying to charge batteries without inverter because it is throwing a breaker and won't connect to Generator. Got a text from my electrician who said to flip transfer switch, then power house by controlling breakers, which I can do. Not sure what is Order of Go here. Messages out to you all and electrician, but it is Sunday, and I have house full of guests, so uncertain till I hear back from someone.

Turn off Inverter? Flip transfer switch to ON, then turn on Generator?? Or which?


  • BB.BB. Super Moderators, Administrators Posts: 30,520 admin
    What do DO NOT WANT is the generator and the inverter AC outputs tied together--Especially when both are turned ON.

    Best best bet turwn off the inverter. Turn off the Inverter AC output (to main panel). Then turn on the AC genset to main panel (you can start and warm up the AC generator first, then turn on the AC transfer breaker).

    A "real" set of transfer switches will have an interlock so that it is impossible to turn both AC inverter AC output and the generator AC output on at the same time (connecting inverter+genset AC output together will cause lots of smoke and damage if connected together for "typical" off grid inverters and gensets).

    I have seen a commercial installation where their or key based breaker interlocks. The electrician (or trained employee) turns of the inverter output breaker and uses a key to lock-out the inverter, and uses a second key to unlock the genset breaker so that it can be turned on). I have seen lockout breaker hardware used by electricians to service equipment (lock out AC branch circuit before working on dangerous equipment).


    It is a good way to make sure that nobody (including you when you have a brain freeze) turn on the wrong breaker at the wrong time (i.e., lockout bypass breakers when not in use).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • muirhousemuirhouse Solar Expert Posts: 82 ✭✭
    Hi Bill. Remember, I have two inverters working in sync, 4048 and 4048 plus. This is what I did: Turned on Generator, did not flip the Generators Load breaker on, just warming it up. Then went to basement flipped the top breaker on the 4048 only as shown below before the flip, and left the 4048 the way it was (i.e., not disconnected). Then I flipped the breaker on the Generator and watched the meters views of 4048 plus picking up AC2, and the 4048 showing nothing. The Battery volts actual rose from 49 to 54 on meter windows of both inverters, showed all the normal readouts of on the 4048 plus, indicator showing bulk charging and nothing blew up. Going back in to the house, learned that that breaker turns off all the circuits connected to it in the house (which is my case is almost everything but the refrigerator). Then the sun came out strong, I turned it all back to normal, and now I know what to do til I figure out what is happening with the 4048 breaker tripping under a normal attempt at charge by the generator!  So, Yeay! Thank you for the input, and any more comments you may have. I was unsure about what would happen if I turned both inverters to 'OFF' with the red inverter buttons, so I didn't. Wasn't sure if the bypass switch would work if I did that.
    lipped transfer switch bar to ON

  • mike95490mike95490 Solar Expert Posts: 8,766 ✭✭✭✭✭
    Your electrician needs to show you how to run your system. 
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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