Cessna 182P Shore Power

Discussion in 'Maintenance Bay' started by Pilot Steve, Mar 26, 2020.

  1. Pilot Steve

    Pilot Steve Pre-Flight

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    Has anyone had success using the external power port on a 182P for shore power or only to use to jump?

    I'm trying to determine if my solenoid inside the external plug is defective because it will not allow power to the aircraft from shore power.
     
  2. 455 Bravo Uniform

    455 Bravo Uniform En-Route

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    I believe connecting to that plug disconnects power to all but the starter. So if you are updating a GPS database or need to keep the master on for some reason, you will wear down your battery even if you have power going into that plug.

    Do you hear a solenoid click when power is applied to the external port?
     
  3. Pilot Steve

    Pilot Steve Pre-Flight

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    Negative on the solenoid click. That is actually the issue I'm trying to deal with if the solenoid is defective or if it is just not designed for shore power. I have power to the starter solenoid when plugged in.

    Thanks!
     
  4. Bell206

    Bell206 En-Route

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    What S/N aircraft? Define shore power, i.e., what you want to power up? If I recall correctly, if your aircraft has a split bus bar you can only power up the primary side (electrical circuits) but not the avionics bus with the external power plug. This is controlled by a separate contactor/solenoid that operates off the external plug. Your POH should define what it powers in Ch 7 I believe.
     
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  5. Kenny Phillips

    Kenny Phillips En-Route

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    We always called that a 'starter plug'.
     
  6. Pilot Steve

    Pilot Steve Pre-Flight

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    This is absolutely why this forum is so amazing. You pointed me right at the answer. It is on page 7-1 for me in the POH.

    I remembered the part that said, "A ground service plug receptacle may be installed to permit use of an external power source for cold weather starting and during length maintenance work on the airplane electrical system."

    It was the next bit I forgot, "(with the exception of electronic equipment.)"

    1,000 life karma bonus points to you.
     
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  7. Dan Thomas

    Dan Thomas Final Approach

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    That plug has three pins in it. One big one positive, another big one is grounded, and a smaller one is the trigger that closes the contactor that connects the positive pin to the system. The external power triggers that smaller pin. Trying to get power OUT of that port is futile unless you had some alternate means of closing the contactor, which would qualify as a major modification.
     
  8. Pilot Steve

    Pilot Steve Pre-Flight

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    I fully resolved. my problem the easy way. Gave up. With the help of kind people here I was reminded about the age-old life hack, RTFM (Read the F*****g Manual). Problem solved. :)
     
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  9. 455 Bravo Uniform

    455 Bravo Uniform En-Route

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    I thought I read somewhere one late night browsing the web 2-3 years ago about a mod (probably not “legal”) to allow external power to feed the entire electrical system, including charging the battery. Seem to recall there was a simple rewire of one or two solenoids (battery/master contractor)? I’m stretching my memory here...
     
  10. RandyB

    RandyB Filing Flight Plan

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    So if I want to update databases, mess with the avionics etc for a long period of time I must use a battery tender or similar to keep my battery charged in my ‘79 R182? I think I answered my on question
     
  11. chartbundle

    chartbundle Cleared for Takeoff

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    Don't be sure, check the POH/diagram for your airplane. They've certainly changed it a few times. The R182 POH I have access to shows the ground power plug will power the primary bus as normal(and avionics as normal with the avionics master) and can engage the master relay if you turn on the master to charge the battery as well.
     
  12. Bell206

    Bell206 En-Route

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    The alterations I recall on aircraft with split buses were all legit (337) and it was a simple switch to drop a ground to a relay. They were working survey aircraft. But it depended on aircraft as some aircraft did power all the electrical systems.

    FYI: If I needed extended external power for mx on those types aircraft, I had a re-purposed power supply that I would connect direct at the battery cables minus the battery.
     
  13. Dan Thomas

    Dan Thomas Final Approach

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    It might depend on the system. We fed the whole system of the Cessna restart airplanes ('96-on) through the external power port when doing troubleshooting or G1000 upgrades. Some older systems would switch the master solenoid on along with the external power solenoid so that power to the starter solenoid was available.
     
  14. RandyB

    RandyB Filing Flight Plan

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    I thought my POH stated as you posted above. I don't have it with me now. But it seemed, if I remember correctly, that the battery voltage continued to drop when I attempted to provide power through the external power port and I powered on the avionics.
     
  15. Jim Carpenter

    Jim Carpenter Pre-Flight

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    FWIW, in my home library, I have a POH for a 1977 C172 XP, it's Sec. 7 entry says as mentioned above, "...….split bus bar...….Therefore, the external power source cannot be used as a source of power when checking electronic components." Then, the 1978 182Q POH has different verbiage, saying that "just before connecting external power, the avionics switch should be off, and the master on" and other paragraphs about providing power to avionics. So, it appears that between '77 and '78 is when Cessna changed the bus configuration, the lesson being, I suppose, check your specific model and POH.
     
  16. PaulMillner

    PaulMillner Pre-takeoff checklist

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    If you trust the quality of your aux power, you can put a switch by the aux contactor to defeat the wire that locks out the avionics bus relay. See the schematic in the back of the service manual... the switch could be located in the panel, too, but a little harder to locate the wires there...