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LA48340's avatar
LA48340
Explorer
Feb 17, 2016

Progressive Dynamics charger PD4045

I am trying to wire up PD4045 "Mighty Mini" in a 10' utility trailer/workshop. I have the AC side figured out. On the 12 V side....there are 12 wires coming off the fuse bar. 2 red are for 30 amp...10 black are for 20 amp uses. I have the battery grounded to the chassis. There are 2 lugs on the 12v side for battery + and -. Does the charger get its ground from someplace other than the batt -? With this connection eliminated I still get output on all the 12V feed wires. Without both battery + and - wires connected don't see how the battery is supposed to charge. I wrote to PD..they told me there are no neg connections needed and told me to consult an RV specialist. thanks for any insight.
  • RoyB's avatar
    RoyB
    Explorer II
    Perhaps this diagram from google search may give you some ideas...



    Sorry about resolution - maybe I can find a better photo...

    Might be some good info in this link for you...
    LINK

    Roy Ken
  • There should be a ground connection near the battery. There should be a ground connection between the AC ground buss and the rigs frame.
    All the DC grounds should be connected together and then connected to the ground. The positive side would be connected to the output side of DC distribution panel.
  • Converter + & - (AC Power black + top lug/white - bottom lug)

    Battery + & - (DC Power Pos cable and Neg cable from battery)




    Diagram from 'installation instructions'
  • Question: Is a wire needed from the ground bar (bare wire) on the AC side to the battery (-) which in turn is connected to the chassis frame. thanks.
  • The power center's ground bus should be bonded to the vehicle chassis directly. From what pictures I can see online, I think PD intended this to be done via the mounting screw adjacent to the ground bus bar, which goes through a little angle iron thingy on the back side that also connects to the ground bus bar. If it's not being bolted to some metal framework in the trailer, a ground strap or wire of some sort should be run (probably to a terminal on the bus bar) to bond the AC ground to the trailer chassis.

    Note that the safety ground from the power center should go directly to the vehicle chassis, not to the battery negative terminal. It needs to be properly bonded even if the battery is removed or disconnected. There's no need to connect the AC ground to the battery directly in any way. (For that matter, the DC negative connection of the power center doesn't need to connect directly to the battery, either; it can go to a good chassis ground, leaving just one connection at the battery negative, that to the chassis.)
  • OK..the way I see this then: Both the AC ground (bare wire buss) and the Batt (-) converter lug go directly to chassis ground on separate wires. Then one wire from the battery (-) to that same ground point on the frame. It seems with the PD directions provided..you have to guess what the designers intentions were or be an experienced RV tech. I am not the later just trying over-do a little trailer with a workbench in the nose.
  • It should not use the same connection point, but yes they both go to the chassis frame.
    The manual says you should contact qualified electrician to do install. Some not many know the requirements of the RV section of the NEC.
  • You can connect all (-) phases of DC and the AC ground to the same point on the trailer's chassis (frame) or connect the DC (-) to any point on the frame and the AC ground to any point on the frame. You just want the battery (-), the converter's DC output (-), the 12V distribution panel (-), and the AC load center ground bus all connected to the frame of the trailer in some manner.

    MO is that multiple ground points can lead to separate system failures. A single ground connection, prepared so that any wiring is in good contact with frame steel and protected with an anti-corrosion material is the best choice. If proceeding this way, drill and tap a hole for fastener. Use a serrated locking washer and flat washers between wire terminals. This allows for a secure connection. Alternatively, a good. larger, self tapping bolt can also be used.