removing cables safely

leaf Solar Expert Posts: 37 ✭✭✭
I need to remove some cables between a regulator and solar batteries. The regulator is not connected to a panel currently, but there is a second regulator that is connected to the batteries, that is also connected to a panel. I will have to remove all cables from the batteries to take off the ones I'm wanting to remove today. There is also a separate line for a water pump coming off the same battery posts.

None of that is working properly, and I want to take take the regulator that has no panel out of the system before I start trouble shooting.

Is there is a specific order I should remove the cables in? Anything else I need to know?

The batteries are 2 x 6V in a 12V system. The regulator I want to disconnect is a sunsaver 10 Amp, the regulator I want to stay connected is a generic Chinese regulator that came with the panel (I can find the specs if needed).


  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    The short answer is disconnect stuff when there is little or no charging or load current going to or from the battery. Open breakers if available, or cover panels and turn off loads to avoid "interesting" arcs when you lift cables from batteries.

    The controller you want to keep alive should see battery voltage first, then panel voltage once booted, so hopefully you have a way of doing that.
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • leaf
    leaf Solar Expert Posts: 37 ✭✭✭
    The panel is not that accessible to cover. Do you think it would be ok to disconnect in the hour before it gets dark? It's mid summer here, panel is nearly flat mounted facing north, altitude around 45S.

    It looks like I am going to remove the batteries.

    Because the batteries are old and dodgy (re other thread), anything I should do re safety, offgassing and possible sparking? I can leave the locker open for a while. Should I leave the caps off for a while too and then put them on again before removing the wires? I'll wear goggles.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Leave the caps on, to keep acid from sloshing out.

    When you start disconnecting stuff, the charging & gassing should stop, and in a short while, most of the explosive gas will not be replenished.  If the battery room is well vented, and all other gear off, there should be minimal spark removing the wire.

    When you re-attach the wire, you will be instantly charging up the caps in the gear and that is likely to make a spark.
    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

    gen: ,

  • leaf
    leaf Solar Expert Posts: 37 ✭✭✭
    thanks, that's good.