Forum Discussion

phemens's avatar
phemens
Explorer
Jul 01, 2019

Questions about wiring for Samlex inverter/charger/converter

Hi,
In the process of installing a Samlex 3012 inverter charger. This will replace existing stand-along 2000W inverter, along with my Boondocker converter/charger.

Couple of questions, sorry if these seem basic, but want to make sure I do it right (not an electrician, but can get it done properly with right guidance!)


I will wire directly from the shore power receptacle (the marine style twist) to the Samlex Grid input using 8 AWG. Right now it goes to the distribution panel.

Samlex wired to bank of batteries (4x100AH LIFePO4) with 4/0 (fused)
Samlex grounded to chassis.

Samlex AC output (8AWG) back to Main breaker in distribution box (?) - this is the part I'm unclear on. Part of the confusion is that the way the rig is wired now, if I cut the main breaker on the distribution panel, all goes dead on AC - fine. However, if I leave breakers on, but turn off power to the Boondocker converter/charger, I lose power to the refrigerator (maybe other things, haven't checked) - does the fridge require 12V to run on 120V?

Thanks in advance
  • pianotuna's avatar
    pianotuna
    Nomad III
    Jul 01, 2019
    Yes, the fridge requires 12 volt for the control board.

    If the roof air has a "wall" thermostat, it also requires 12 volt.

    So does the water heater, and furnace.

    Am glad you went #8.
  • 2oldman's avatar
    2oldman
    Explorer II
    Jul 01, 2019
    phemens wrote:
    However, if I leave breakers on, but turn off power to the Boondocker converter/charger, I lose power to the refrigerator
    How do you 'turn off' the charger? When I went whole-house I installed an spst switch for the converter 120v power.

    Your 12v appliances should never lose power simply if the charger is off...unless you've messed with the wiring. That means you could never boondock.

    Rest of it sounds good.. especially the Li. Did you consider going higher voltage?
  • BFL13's avatar
    BFL13
    Explorer II
    Jul 01, 2019
    What is the "shore power receptacle" in the RV? Only thing mine has is the shore power cord going to the Main breaker. ( with no installed generator and transfer switch)
  • phemens's avatar
    phemens
    Explorer
    Jul 01, 2019
    BFL13 - Yes, that's what I mean, the shore power cord, mine is marine style (hence receptacle).

    2oldman, The Boondocker charger/converter has a physical on/off switch. I guess the reason that the RV loses 12V right now is because I disconnected the batteries while swapping over to the LIFePO4 units. The converter provides 12V to the rig when connected to shore power, no?
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Jul 01, 2019
    Yep, I agree with everything here.

    For a better system, I would isolate power to the A/C and power to the Hot water heater so if shore power is non-existent neither the A/C or the hot water heater will be powered. A powerful enough generator would return things to "normal" shore power operation via the shore power cord.
  • phemens's avatar
    phemens
    Explorer
    Jul 01, 2019
    I almost never use the A/C or hotwater heater on 120V, they're both off.
  • phemens's avatar
    phemens
    Explorer
    Jul 01, 2019
    I did consider going higher voltage, but could not find a reasonable all-in-one unit that would give me what I was looking for (Samlex doesn't offer a 3k W inverter/charger at more than 12v for now).


    2oldman wrote:
    phemens wrote:
    However, if I leave breakers on, but turn off power to the Boondocker converter/charger, I lose power to the refrigerator
    How do you 'turn off' the charger? When I went whole-house I installed an spst switch for the converter 120v power.

    Your 12v appliances should never lose power simply if the charger is off...unless you've messed with the wiring. That means you could never boondock.

    Rest of it sounds good.. especially the Li. Did you consider going higher voltage?
  • BFL13's avatar
    BFL13
    Explorer II
    Jul 01, 2019
    I was told on here that you cannot operate the 12v system with no battery if you have an inverter/ charger, because it needs battery 12v to power it up to use in the first place. Unlike a converter, which does not need the battery.

    I don't know if there is a likely scenario with the Li bank if you would ever want to run the 12v with no battery in the future. If so, you could hang onto the converter as a spare for doing that.

    IMO hang onto it anyway. You can use cut off jumper cables in the output terminals and use it as a portable charger with the jumper cable clamps to the battery. Makes for redundancy in case the charger in the I/C is not working for some reason.
  • time2roll's avatar
    time2roll
    Nomad
    Jul 01, 2019
    I recommend turning everything off and unplug during this conversion or any major electrical work 12v or 120v.

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