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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

19 Replies

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  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 04, 2019
    Now we are talking... That is in fact what Camping world did with my converter when they put in the inverter. For various reasons I disabled the inverter's charger and plugged my OEM back in (You can't beat progressive Dynamics Charge wizard for flooded wet cells).

    What others have said about the fridge (340 watts) and water heater (most are `500 mine is 375) and so on applies.. This is why you use the sub panel
    A/C Fridge and Water heater are on the MAIN panel.. Some outlets as well. Rest of outlets. MIcrowave and electronics on the SUB (inverter) panel.
  • phemens's avatar
    phemens
    Explorer
    Jul 04, 2019
    Yeah, I was planning on keeping the Boondocker there as a backup for sure, it's a plug-in unit (AC in), so that's the easiest, just unplug and forget till needed.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 03, 2019
    I don't know why they put the Converter on the Fridge breaker.

    Myself I'd run a sub panel for the inverter (IN fact that is how my rig is wired) but in your case.. locate the converter and either disconnect the 120 volt in or add a switch in that line (A switch with a lockout so you can pin it off) I think the boondockers are stand alone converters so this should be easy.

    I will keep the boondocker in place (Just turned off or ac disconnected) so as to have it when (not if) you need it years from now.
  • phemens's avatar
    phemens
    Explorer
    Jul 03, 2019
    I have 2 mutally exclusive conditions I need to satisfy:

    1) keep the fridge running when parked (not camping) - I need a 12v source for this even when running off 120VAC

    2) ideally keep LIFePO4 at 50-80 SOC when idle for extended period. This means I don't want my charger topping them off

    The Samlex will not provide 12V on it's own (my current Boondocker does as converter), so if I activate the battery cut-off, I do not satisfy condition 1).

    One option Samlex suggested is to keep the Samlex on in 2 stage charging mode, let the batteries draw down on parasitic load and then trigger charging when the low threshold voltage is met (I could set that at 50% or 12.2V.
    Other option is when arriving home, turn off Samlex completely, set battery cut-off to 'off' and plug shore power directly into the Boondocker to provide 12V and 120VAC to RV for fridge.


    2oldman wrote:
    phemens wrote:
    I need a separate source of 12V to the RV while batteries are off to keep appliances going.
    I'm not following this part.

    phemens wrote:
    Using state-of-the-art technology, the Samlex EVOTM inverter/charger operates at 165 million instructions per second with lightening fast load & response times,...
    I contacted them about their spelling.
  • phemens's avatar
    phemens
    Explorer
    Jul 03, 2019
    Here's the reply from Samlex:

    The EVO-3012 does not provide 12 Volts. It will charge a 12 Volt battery bank when AC is available and will use the 12 Volts to generate 120 VAC if no AC is available, but it doesn’t “distribute” 12 VDC… Not knowing what is cut off by the switch I can’t say what will or will not still operate. The EVO can not function if it does not have an attached battery.
    Need more information.
    Standby mode simply keeps the EVO on (no charging or inverting), it will have no impact on 12 Volt loads, -as mentioned above it’s not involved in 12 Volt distribution.

    If the EVO is put into a charge profile with no float (turn charger off after 2nd stage) then the batteries will drain with any loads you have and the charger will restart when the low threshold (RESET to BULK) is reached. This may be a better alternative and will keep the battery cycling but very slowly (depending on the load(s).
  • 2oldman's avatar
    2oldman
    Explorer II
    Jul 03, 2019
    phemens wrote:
    I need a separate source of 12V to the RV while batteries are off to keep appliances going.
    I'm not following this part.

    phemens wrote:
    Using state-of-the-art technology, the Samlex EVOTM inverter/charger operates at 165 million instructions per second with lightening fast load & response times,...
    I contacted them about their spelling.
  • phemens's avatar
    phemens
    Explorer
    Jul 03, 2019
    The Samlex has built in surge protection and line conditioning:

    Using state-of-the-art technology, the Samlex EVOTM inverter/charger operates at 165 million instructions per second with lightening fast load & response times, has 9 points of physical protection monitoring (being scanned up to 10,000 times per second) to detect fault conditions & protect itself in a vast range of adverse environments.

    The Boondocker is currently wired for 12V straight to battery bank and there is a separate 12v feed from batteries to distribution box.
    If I can't get the Samlex to turn of inverter & charger while maintaining 120V & 12V to RV, then I will re-route the wiring from the Boondocker to battery bank directly to distribution panel.

    I actually kind of want to do the opposite of what you are suggesting. I have no lack of ways to top up the batteries, I don't need a charging source. I need a separate source of 12V to the RV while batteries are off to keep appliances going.
  • ndrorder's avatar
    ndrorder
    Explorer
    Jul 02, 2019
    Wiring straight from the inlet plug to the inverter risks an expensive inverter if shore power is wonky. Is there room for a surge protector/circuit breaker in between?

    If the Boondocker is still connected to the batteries, it should pass 12Vdc through to the 12Vdc distribution panel (fuses) when there is no 120VAC. If not, how is the 12Vdc distribution tied to the batteries? Easiest solution is to disconnect the Boondocker at the circuit breaker and leave the battery cables in place which would also keep the salesman switch in play for storage and any charging circuits from the tow vehicle.

    Many 120VAC appliances in an RV require 12Vdc for operation. Fridge, thermostat, detectors, water heater, furnace, etc.
  • 2oldman's avatar
    2oldman
    Explorer II
    Jul 01, 2019
    phemens wrote:
    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?
    Yeah, you gotta connect up the 12v trailer feed. Most converters I'm aware of do that, yes.
    phemens wrote:
    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).
    There are all kinds of 24 and 48v ICs, Magnum being one. Just got an Outback. Killer unit.
  • 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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