Voltage drop

Discussion in 'Wiring' started by volts600, Aug 20, 2011.

  1. volts600

    volts600 New Member

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    So I brought home our NTU pup and cleaned and set her up. It has a new battery Marine/rv battery (not true deep cell but they put it in for free). So when the pump runs the lights dim about 50%. I am an electrician so I will bring my meters and some tools home Monday, but is this normal with other peoples trailers? Just seems like alot of drop to me and that is with it plugged in. It as about the same with it unplugged. Trailer is a Coleman Casa Grande.
     
  2. Erwin

    Erwin New Member

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    I would start by checking/cleaning ALL the grounds.
     
  3. mv520

    mv520 Active Member

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    No, not normal. Some dimming yes, but not "50%"

    In tracing the wires/connections, note the power for your ceiling lights *probably* comes up to the ceiling from a pair of wires that are actually on the outside of the PUP just to the rear of the left rear corner by the lift post, with a connector exposed.
     
  4. volts600

    volts600 New Member

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    Well I brought my better half out to look at the condition that is happening and after much fooling around (with the trailer) we now agree that the dimming is about 20%. Still seems like alot to me so tomorrow I will be checking the grounds (only common connection). I might upsize the wiring from the battery to the convertor from #10 to #8.
     
  5. marcham

    marcham New Member

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    Switch to LEDs, any good quality LED won't dim at all if the voltage sags a little. What gauge is the wire from the battery to the fuse box?
     
  6. Dammitjim

    Dammitjim New Member

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    I'm glad you clarified that [LOL]
    There could also be loose connections. I recently had problems with my A/C and the power outlet to which the A/C was connected to was only registering 85V. I took the outlet box apart and sure enough, the cables were all loose.
    Good luck in this new adventure and congratulations on the new addition [PU] to the family!
     
  7. volts600

    volts600 New Member

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    The wire from the battery to the fuse box/converter is only a #10AWG. A little small in my opinion. Going to upsize it after I check all the grounds.
     
  8. marcham

    marcham New Member

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    That's what I have as well. My incandescent lights would dim a little bit when the pump was running, but 10AWG is fine for a 20-25' run considering the 6-8Amp the pump draws.

    That being said, I'm going to increase the wire size on mine because the voltage drop seems to affect the converter's mode selection, it never seems to go to float, unless the battery is close and hooked up by thick booster cables.
     
  9. kpthook

    kpthook New Member

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    I agree on going to a #8. Also if you have the lights on and depending on the fixture style it not just 6-8 amps of the pump. If the fixtures are like mine then it's 18 w bulbs (921's) x 4 or 6 amps for lighting. So now your at 12-15 amps plus whatever else might be on.

    I just upgraded my converter and to make a long story short going to a #8 between the battery and converter made a big difference on reducing the voltage drop.
     

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