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ThruTraffic's avatar
ThruTraffic
Explorer
Oct 06, 2022

Voltage Drop - NOT Park Problem

Phoenix Cruiser 2551 30a service

- First noticed it when A/C turns on then stumbles. Voltage at another RV outlet dropped well below 100. Capacitors good. A/C working fine until this point. A/C did trip ITS 20a breaker one time. 30a main held.
- Problem persists when disconnected from shore power and generator running. Main indicator this is an RV wiring problem not shore power delivery system.
- Thermostat threw an E1.
- Inverter monitor behind driver seat threw an E2 and E5.
- Can turn on toaster at one outlet voltage drops 3v
- Can turn on hot water heater voltage drops 3v
- Hooked up a 15a draw elect device drops 5v
- System wide problem
- Checked connections at transfer switch, socket for shore power, junction where old EMS used to be, mains in RV breaker panel. Checked neutrals, grounds and feeds. All tight.

Shore power is my RV lot shop. I can find no voltage issues there even under load. Problem is on the load side of the RV sidewall shore power connector. Even tried different cables and installed a new 30a breaker.

Am I missing any 120v main connections in the RV not listed above?

I’m stumped.
  • ThruTraffic's avatar
    ThruTraffic
    Explorer
    Oct 07, 2022
    wa8yxm wrote:
    YOu said "Not a park problem" but how did you determine that.

    Now.. measure voltage at park 120 NO LOAD
    plug in and fire up water heater (A safe load for testing) Voltage 110.. Park problem.. (Measure voltage at the other outlets on the park pedestal not in the RV)

    Other posiblities if a 50 amp RV you may have a weak/open neutral
    OR you might have a bad connection the list of suspects here starts with the plug.

    Bright and shiny or near black blades (Polish 'em up)
    Connections inside the plug if not molded and welded connections
    The outlet end of the cord where it hookes to the RV (If detachable) and the RV's INlet (Same song as the plug)

    THe connection to the Auto Transfer switch (Both in and out) if any
    The connection to the main distro panel and the Main breaker itself.

    In short anywhere current flows.

    Electricity is like water in a hose.. If at any point the hose is "pinched' or some idiot put a flow restrictor in a fitting.. LOW FLOW.


    From initial post : Problem persists when disconnected from shore power and generator running. Main indicator this is an RV wiring problem not shore power delivery system." If I took the rig to Walmart's parking lot and ran it off the generator and still had the same problems would one believe it was shore power?

    30amp service (has a neutral too)

    Nothing wrong with transfer switch contactor contacts or lugs.

    All power and neutral feeds have been checked. None cracked or broken. All terminals tight.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Oct 07, 2022
    YOu said "Not a park problem" but how did you determine that.

    Now.. measure voltage at park 120 NO LOAD
    plug in and fire up water heater (A safe load for testing) Voltage 110.. Park problem.. (Measure voltage at the other outlets on the park pedestal not in the RV)

    Other posiblities if a 50 amp RV you may have a weak/open neutral
    OR you might have a bad connection the list of suspects here starts with the plug.

    Bright and shiny or near black blades (Polish 'em up)
    Connections inside the plug if not molded and welded connections
    The outlet end of the cord where it hookes to the RV (If detachable) and the RV's INlet (Same song as the plug)

    THe connection to the Auto Transfer switch (Both in and out) if any
    The connection to the main distro panel and the Main breaker itself.

    In short anywhere current flows.

    Electricity is like water in a hose.. If at any point the hose is "pinched' or some idiot put a flow restrictor in a fitting.. LOW FLOW.
  • ThruTraffic's avatar
    ThruTraffic
    Explorer
    Oct 07, 2022
    time2roll wrote:
    ThruTraffic wrote:

    - Checked connections at transfer switch, socket for shore power, junction where old EMS used to be, mains in RV breaker panel. Checked neutrals, grounds and feeds. All tight.
    Ok they are tight. Now check voltage under load.

    Could also be the compressor is failing. Get an amp draw on the air conditioner.


    Already done both those things. Check initial post.
  • time2roll's avatar
    time2roll
    Nomad
    Oct 07, 2022
    ThruTraffic wrote:

    - Checked connections at transfer switch, socket for shore power, junction where old EMS used to be, mains in RV breaker panel. Checked neutrals, grounds and feeds. All tight.
    Ok they are tight. Now check voltage under load.

    Could also be the compressor is failing. Get an amp draw on the air conditioner.
  • BB_TX's avatar
    BB_TX
    Nomad
    Oct 07, 2022
    Certainly sounds like a point of poor connection in your incoming power. V=IR or voltage drop is equal to current times resistance.. Example: if you had a poor connection of 1 ohm resistance with 1 amp current flowing thru it you would have a 1 volt drop, or loss, at that point. If you increased the current to 2 amps then you would have a 2 volt drop at that same point. That sounds like what you are seeing. You would also have localized heating at that point.

    Looks like you have already covered all the obvious. You might look again at those connection points to see if crimps or clamps are partially on the insulation. Another possibility is partially broken wire. That can sometimes be hard to find as sometimes it happens inside insulation with no apparent damage.
  • ThruTraffic's avatar
    ThruTraffic
    Explorer
    Oct 06, 2022
    Lwiddis wrote:
    Age of the RV and the converter?


    Both 2011. I'm not seeing any problems with the 12v system. I had the cover off the converter tightening logs. None were loose.

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