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Davidlee64's avatar
Davidlee64
Explorer
Nov 04, 2017

Generac Genny Questions? Updated

I have an 04 KZ Sportsman 5ver with an original install Generac QP55 00862-2 generator. There was no booklet or owners info included with the unit for the genny. I have downloaded the correct manual for it. On this one there doesn't appear to have any kind of transfer switch built in. The output wires from the genny go straight to the AC breaker box. The (suggested) wiring in the manual shows a typical 30 amp plug that would plug into the shore power outlet. I imagine that is so you have to disconnect shore power to use the genny. Smart idea. Can't screw up like that.
But since mine is wired direct, I figure to start it from the genny panel, unplugging the shore power cord, shutting off the CB's on the panel to prevent output going into the system.
I have read somewhere that the genny requires power to excite the windings before the genny will actually provide 120 volts. Am I offbase here?
I am wanting to get the genny up and operating. I have new parts, carb, fuel and air filters, one CB to replace the broken lever on the 20 A one. I know I need to drain the fuel tank as I have no idea how old the fuel is.
I don't wish to damage anything doing the initial startup. Any suggestions are appreciated.
  • Davidlee64's avatar
    Davidlee64
    Explorer
    Nov 11, 2017
    I fired up the genny today. I drained the 12 gallon fuel tank and pulled it out. I substituted a 1 gallon container with mid grade fuel, added Sta-bil to it, and put the fuel line into it. Pumped it up, and gave it a spin. She started up and ran fine. I pulled the shore cord and left the genny breakers off. I took the line from the supply and ran the system dry so no trash left in the line or carb bowl.
    I lifted the shelf in the power center cabinet and there is a box marked "Automatic Line/Generator Switch" so it appears there is an auto transfer switch. This lets me breath a little easier.
  • Davidlee64's avatar
    Davidlee64
    Explorer
    Nov 07, 2017
    Next is to try and lift the shelf in the bathroom cabinet over the power center to locate genny connection.
  • Davidlee64's avatar
    Davidlee64
    Explorer
    Nov 07, 2017
    I have added some pics of genny repairs.
    Carb removed


    New carb


    Old air filter


    New air filter


    Air box installed


    New gas filter and 20 amp breaker


    Together
  • bounder39zman's avatar
    bounder39zman
    Explorer II
    Nov 05, 2017
    This model Generac does not have a built in transfer switch (dont know of any RV type of generator that does). If the generator output wiring is not isolated from shore power line by either a manual or automatic transfer switch, this is extremely dangerous. This generator "excites"
    the field during engine cranking to start voltage build-up by the control board providing 12 volt from battery to field. when voltage comes up to approximately 100vac, a relay on control board disconnects starter circuit, and field flash, the voltage regulator takes over providing field voltage to rotor.
  • Davidlee64's avatar
    Davidlee64
    Explorer
    Nov 05, 2017
    On mine the power center is about 12" behind and above the shore power plug. It is in the bath area under the sink. The genny output goes thru a junction box with a pushbutton reset breaker, then goes thru the bulkhead and up into the power center space. Forward of the bulkhead is the genny and house batteries. The shore power leads also go up into the power center space at this location. I checked first for power at the genny circuit breakers, and got nothing. It seems the only way I will know for sure what is what is to pull the power center out so I can look.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Nov 05, 2017
    How I found my Transfer switch (And almost passed out in shock when it was there)

    I envisioned the wires from the INLET (Shore inlet on the rear Driver's side) to the Power distribution panel (Roughly the center of the coach, in a hall wall the wall is shared between a hall and the half bath) and then from the Generator to the same Distro panel.

    They cross. .In the cabinet under the half bath counter. about 2 feet behind the distro panel..

    I opened the doors and noticed the "Bottom shelf" was blocked off.. Removed the panel (2 screws) and .. There i was.. SHOCK. .THe most logical place.

    (WHy Shock. Well heavy (50 amp) WIre is not cheap. and they put it were they could use the LEAST wire.. Not the MOST as in so many other RV's)
  • Davidlee64's avatar
    Davidlee64
    Explorer
    Nov 05, 2017
    I didn't think of it when I put in the new converter. I know there is a yellow Romex line from the genny up into the compartment where the fuses are located. It looks like I will have to open this up again to see what is what.
  • DrewE's avatar
    DrewE
    Explorer II
    Nov 04, 2017
    If the generator can actually be connected to the shore power cord, so that the plug is live or so that shore power energizes the generator head, fix that ASAP before using either one. It should be physically impossible to have more than one connected to the electric system at any time.

    I very strongly suspect, though, that there is a transfer switch of some manner in your system, quite possibly attached to the electric panel.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Nov 04, 2017
    It is very uncommon for the generator (RV TYPE) To have a built in transfer switch,, The Transfer switch (if any) is a separate item elsewhere in the RV, Mine is in the half bath believe it or not, Under the counter in a closed off place.

    Generator goes to ATS
    Shore to ATS
    ATS to Distrubition panel

    NOTE: on 30 amnp RV's the generator may also feed one Air Conditioner (20 amp breaker).

    Note: Some RV's have what I call a "poor man's transfer switch" This is an outlet you plug the RV into. yes it sort of plugs into itself

    The generator feeds the outlet

    But the only Generators that have built in transfer are Military or Home back up units.. and even there the ATS is separate from the Generator.. Just inside the same cabinet.
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Nov 04, 2017
    Residual magnetism in the rotor poles provides initial excitation to the stator leads. Long term off line may allow the rotor to fully demagnitize. Then a 6 volt lantern battery is used to "flash the field" The voltage regulator has dedicated field polarity. Don't flash the field reversed polarity!

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