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letup27's avatar
letup27
Explorer
Mar 26, 2020

Installing inverter w/charger and transfer switch

Im installing a AIMS 2500 Watt Low Frequency Pure Sine Inverter Charger 12 VDC to 120 VAC in my Rockwood 2506. Im hard wiring to the panel box. The positive wire on the battery terminal goes to the power jack and I think the electric brake before running to the panel box. I hook up the battery to the inverter posts, the shore power to the ac in and the ac out to the 30 amp breaker in the panel box. How will power get back to my jack?
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    letup27 wrote:
    so I should add a terminal stud and connect the positive and existing dc wire and run it to the positive side of the inverter? Im removing the existing converter. Should I install a 300amp line fuse?


    You should add a proper "T" fuse (That's a fuse type) not sure but the owner's manual for the inverter will list the fuse size 250-300 amps is not uncommon for a 2000 watt inverter. not sure about yours.

    Run one HEAVY (00Ga or bigger) wire from battery positive to fuse. this should be short. 1 foot or less. then move all the wires currently attached to battery positive to this fuse. I'd hook 'em to the battery end of the fuse same terminal I hook the battery cable to (use it as a distribution stud) and then the other end is connected to the inverter in the next compartment. also using heavy (00 or bigger) wire.

    When I say I would do it. I mean I did it.

    Makes it a lot easier when I need to change batteries as there is only ONE WIRE hooked to the battery positive instead of several.
  • I appreciate you guys saying I should call an electrician. I was in the house construction business for over 35 years and know a good amount about ac wiring, its the dc side Im not 100% on. :) As far as installing the inverter, if I don't understand 99% on how it works then I will be on the phone too one of my subs. Again thanks for that advice. Getting to dam old, not sinking in like it use to...:)
    Why would I need a transfer switch if one is in the inverter? My run from battery to inverter is about 6', so Im using 1 awg welding cable with a 300 amp line breaker. Should I install a disconnect? Running from inverter to RV panel box is 10/2 romex. I don't have the inverter yet its on order. I want to pre wire while Im waiting for it. I realize I can't run air and heater off the inverter and my though was only have those breakers on while hookup to shore power, but if you think a sub-panel is better then I will install one. The information Im getting on the internet is that I should take out the existing converter, because the inverter is a charger/ats. Since you just installed one could you send me a wire diagram on how you installed it? Would really help (pictures worth a 1000 words).
    thanks
  • 3_tons's avatar
    3_tons
    Explorer III
    “Since I'm disconnecting the shore line from the 30 amp breaker in the panel box that romex #10 wire has to run to the inverter. Since its not long enough I will have to add a junction box and extend the wire to the input of the inverter.”

    Yes, to the inverters AC input - the inverter is of a shore power ‘pass-thru’ design (with ATS) that senses the loss of shore power and engages upon a loss of shore power...



    “The output of the inverter will run to the 30 amp breaker. Is that correct?”

    Yes...

    “So if I understand this right the existing converter is use to convert a/c to d/c when Im plug into shore power. If its not being used the d/c power will be supplied through the wire I will leave connected to the battery.”

    Almost Correct...Since you are not installing a separate sub panel, the inverter will potentially power up every circuit in your main panel, including the DC converter...This will cause a ‘round-robin’ effect whereby, the inverter will be drawing from the battery while simultaneously attempting to charge the battery via the converter...And without a sub-panel, if the refer was operating on shore power, the inverter will likely drain the battery in short order while attempting to supply the refer...This is why a sub-panel is best, because upon a loss of shore power the converter and typically the refer (assuming LPG/elect), and often the air conditioner, will be divorced from the inverter’s ATS output...

    “If Im correct with all that then my last question would be since I disconnected the existing converter then how will the batteries recharge?”

    You are not disconnecting or altering the existing converter in any way - what you are doing on the AC side is simply splicing the Aims inverter into the shore power supply wire (i.e. shore power in, inverter out to panel) while on the DC side connecting it to your existing battery terminals...

    Based on your questions and your level of unfamiliarity, I agree with cavie and suggest you ‘get it right the first time’ and hire an electrician - in fact I just installed this exact same inverter for a pal and along with a sub-panel, we added a secondary stand alone ATS switch in the circuitry to optimize the
    entire cascade operation...

    Battery cabling size to inverter is also very important..
  • letup27 wrote:
    Since I'm disconnecting the shore line from the 30 amp breaker in the panel box that romex #10 wire has to run to the inverter. Since its not long enough I will have to add a junction box and extend the wire to the input of the inverter. The output of the inverter will run to the 30 amp breaker. Is that correct?
    So if I understand this right the existing converter is use to convert a/c to d/c when Im plug into shore power. If its not being used the d/c power will be supplied through the wire I will leave connected to the battery.
    If Im correct with all that then my last question would be since I disconnected the existing converter then how will the batteries recharge?


    You can not power the whole RV of the inverter. You will need to install a small Sub panel and select just a few circuits to be inverted. You need to call an electrician. This is not a DIY over the internet project.
  • letup27 wrote:
    Since I'm disconnecting the shore line from the 30 amp breaker in the panel box that romex #10 wire has to run to the inverter. Since its not long enough I will have to add a junction box and extend the wire to the input of the inverter. The output of the inverter will run to the 30 amp breaker. Is that correct?
    Yes although if you have access I would pull an entire new section of wire and avoid the Jbox.
  • Since I'm disconnecting the shore line from the 30 amp breaker in the panel box that romex #10 wire has to run to the inverter. Since its not long enough I will have to add a junction box and extend the wire to the input of the inverter. The output of the inverter will run to the 30 amp breaker. Is that correct?
    So if I understand this right the existing converter is use to convert a/c to d/c when Im plug into shore power. If its not being used the d/c power will be supplied through the wire I will leave connected to the battery.
    If Im correct with all that then my last question would be since I disconnected the existing converter then how will the batteries recharge?
  • You have new wire for the inverter sized 1/0 minimum correct? I recommend 200 amp fuse if the wire is longer than a few feet or passes through anything.

    As said... leave all the OEM wire and connections in place. Just connect the inverter 12v terminals direct to the battery with the new wire. The wire to the jack is not removed or spliced.
  • so I should add a terminal stud and connect the positive and existing dc wire and run it to the positive side of the inverter? Im removing the existing converter. Should I install a 300amp line fuse?
  • Leave the existing DC wiring in place and just add the inverter/charger DC wiring to the battery. Any charger needs to be off when the inverter is on.

    BTW The transfer switch only switches the A/C from shore and inverter.

    A 2500W inverter can draw 200A DC hence a large battery bank is needed.

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