12V DC disconnect recommendation?

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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #32
    Re: 12V DC disconnect recommendation?
    _OS_ wrote: »
    I guess it is too late now or is there something I can plug the hole with?

    Regards,
    Ole

    The plugs are called (in the US anyway) "KO Seal".

    http://www.electricsupplyonline.com/prod/mulberry-knock_out_seals.php

    Nice clean job - as usual. :)


    EDIT: I should have mentioned...

    You *can* just snap the KO seal into the hole, but for a permanent installation, it's better to snap it in, then bend the tabs down flat against the box.
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  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    #33
    Re: 12V DC disconnect recommendation?

    Thanks! I guess my dealer in the US have them so I will get them with my next order.

    Ole
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #34
    Re: 12V DC disconnect recommendation?

    Any electrical supply house should stock them. In fact any good hardware store that sells electrical parts (breakers/boxes/etc) should have K/O plugs of some sort. There are pop in ones, as well as wing backed ones for bigger holes.

    Tony
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  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    #35
    Re: 12V DC disconnect recommendation?

    Hi Tony,

    I went all over the place and looked for the snap-in bushings and nobody did not even know that they existed so my guess is that I will not find the "KO seals" either. I finally had to order the snap-in bushings from my dealer in the US. Unfortunately I did not order the smaller ones and that is why I have used "PG nipples" in the top right and bottom right. But today I got a little surprise in the mail: three of the smaller ones free of charge from Midnite Solar! I will replace the lower one but the upper one I don't know since there are about 15 wires running through it.

    Does anyone of you know the dimension or type number of the KO Seal that fits the largest hole in the Mini-DC? I will check that auction site if they are listed there. I have measured the hole and it is about 2.6 inches (the drawing in the manual says 2 inches but this is probably do to some convention).

    Ole
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #36
    Re: 12V DC disconnect recommendation?
    _OS_ wrote: »
    ]
    Does anyone of you know the dimension or type number of the KO Seal that fits the largest hole in the Mini-DC? I will check that auction site if they are listed there. I have measured the hole and it is about 2.6 inches (the drawing in the manual says 2 inches but this is probably do to some convention).

    Ole

    "2 inches" would refer to the *inside diameter* of the pipe or fitting which is connected to that hole. The outside diameter of the pipe or threaded fitting will always be larger, and the knockout is sized to allow the threads of the pipe or the fitting to pass through freely.

    If you look at the "1/2 inch" knockouts in that box, you will see that they are actually quite a bit larger than 1/2".

    So, if the knockout is sized for a 2" conduit, then you would order a 2" KO Seal.
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  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    #37
    Re: 12V DC disconnect recommendation?

    Sorry for the delay, I have been disconnected a few days.

    Thanks for the clarification. I did not find them on eBay and it is too little to order from my dealer so I will wait until I have some more items to order.

    I visited my cabin again this weekend and made a mistake and switched off the breaker connected to the Pentametric battery monitor! When I turned it on again the % battery state, Ah since charged and so on were reset! Next time I am there I will remove it from the breaker and use a direct connection to the battery or maybe a fuse instead.

    Ole
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #38
    Re: 12V DC disconnect recommendation?
    _OS_ wrote: »
    Sorry for the delay, I have been disconnected a few days.

    Thanks for the clarification. I did not find them on eBay and it is too little to order from my dealer so I will wait until I have some more items to order.

    Ole

    There is no need to worry too much about doing it "right". The idea is the cover the hole with metal. I suggested the ko seal because you asked if there was something made especially to plug holes like that, but "there is more than one way to skin a cat" (as we say in the US).


    For a 2"+ hole, I might be temped to just take one of these, paint it white and screw it to the box (using screws with nuts, not "sheet metal" screws - I don't like sharp and pointy facing in on electrical boxes):

    http://www.garvinindustries.com/product.asp_Q_parentID_E_413_A_subCatID_E_417_A_prodID_E_1985

    Or, you could use one like this:

    http://www.garvinindustries.com/product.asp_Q_parentID_E_413_A_subCatID_E_417_A_prodID_E_1986

    If you needed the extra ko. If the cover is too "wide", trim off a bit so it fits. It also doesn't matter if the cover is on the inside or the outside.


    It doesn't have to be anything special - you can make the cover out any suitable piece of sheet metal as long as the metal is of adequate thickness.
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  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    #39
    Re: 12V DC disconnect recommendation?

    I visited my cabin again this weekend and did some rewiring of the system:

    I am now running the 12V to the Pentametric through an in-line 2A fuse directly to the battery. This is to prevent accidents like the one above.

    The 40A breaker for the 12V (currently used for lights and gas alarm) is now connected to the upper terminal on the 250A main breaker as suggested in my first drawing above. I know that this is not the recommended connection but I want to have only one breaker that switches on/off all loads. This makes it easier for other people in my family to use the cabin.

    I have removed the 12V box to the left of the Mini-DC (see pic above) and am now wiring the thick, Grey 12V cable directly to the 40A breaker. This cable is buried into the ground and runs from my tool shed to the cabin (about 15 meters).

    I forgot to take a picture of the new wiring but I will do it next time.

    Ole
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