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Cougarnewbie's avatar
Cougarnewbie
Explorer
Mar 15, 2014

Champion 4000w gen question

Ok, to make a long story long, I would like to get a gen for boondocking. I would also like enough wattage to power my gas-fired forced air furnace in the house during a power failure. I have a Coleman 5000w generator 10 hp. (really loud)! No good for camping. This winter our lights went out and I ran a length of romex from the Coleman direct to the furnace. (about 25 ft.) The engine started running rough and the blower motor (7 to 9 amp?) was really laboring. I plugged in a small ceramic heater in the other recepticle and everything smoothed out. Ran like that for hours. Slowly added other lights.(orange cords everywhere) until the motor started running rough again. All we cared about was the heat. Became a balancing act of load or less load. We have some friends that have the Champion 4000w that said it would not run their furnace. I think he back fed through the house wiring. Which brings me to my question. If the Champion puts out 36 amps and the Coleman puts out 45 amps ( Watts divided by 110 =amps) Why was it a problem to run a 9 amp blower with my Coleman and my friend couldn't run the blower with his Champion? Very confused and can't afford a Honda

10 Replies

  • Huntindog wrote:
    Gdetrailer wrote:
    A couple of things..

    Contractor gens like the Coleman typically supply 240/120V. This is accomplished by having two separate 120V "windings" in the gen head.

    The windings are wired in series to provide 240V and the 120V is tapped using the center point of the series wiring.

    Typically on this setup the AVR (automatic voltage regulator) is connected to only ONE of the two windings.

    When heavily loading only one side of the 120V windings which does not have AVR it will cause a voltage sag. To fix that sag you need to add a load to the opposite 120V winding (outlet)and the voltage will on both 120V windings will be corrected for the load.

    You also only get HALF the rated wattage on the 120V outlets with the typical contractor gens. The Champion on the other hand should have a switch which combines both 120V windings properly to give you all the rated wattage on the 120V only outlets (you lose the 240V when the 120V only mode is enabled).

    Additionally modern furnaces tend to have a rather picky control board and depending on the type of fan motor your furnace has it may or may not run correctly.

    If fan is a variable speed fan, it may not like the waveform, frequency or voltage variations which happen with a generator.

    The control boards also will do a system check when power is applied, part of this check is to verify that the neutral (white) and ground (green or bare) are "bonded" together. If no bond is detected (IE open between the two) the board will lockout and prevent the furnace from operating..

    The reason I mention this is some generators do not connect the neutral to the ground and some do..

    If you connect the gen through your breaker box the neutral and ground are bonded in the box and the furnace control board should be happy..

    BUT please, do not "back feed" your breaker box, it is dangerous to you and your family AND the power company linesman.

    By "back feeding" I am talking about not using a proper TRANSFER SWITCH or the proper interlock which forces the main panel breaker into the off position when powering the panel via a generator..

    Back feeding via a double male cable which is often called a "dead mans cord" is also a bad idea..

    DON'T DO IT, there IS a reason that you can not buy power cords with a male end on both ends.

    Power cords are designed with a male end to plug into a outlet and the female end there is no exposed electrical connection that you can touch..

    Install the PROPER generator INLET connector (a generator inlet connector prevents you from making contact with any live or hot pins) with the proper transfer and be safe..
    The furnace uses 12 volts. The method of AC grounding has no effect on it.


    Sorry, you didn't bother to read the OPs post and are wrong, AGAIN.

    OP clearly mention HOME FURNACE and I do not know of ANY home furnaces that run from 12V...

    Huntin' perhaps you could quit quoting my posts, and start reading the OPs post better that would be a good start...
  • I've decided to upgrade our older 120v/240v Champ after seeing that test. Luckily they give them away with the trailers and people list them NIB for the same as I can get for the older version.
  • We live in a rural area where power outages seem to be more frequent. We have a manual transfer switch which I installed and use our Yamaha 2400iS to run 6 circuits simultaneously. Furnace, freezer, refrigerator, kitchen lights/living room, master bedroom, and bathroom. In our situation, if everything is running, we are drawing about 2000 watts and within the limits of the generator. If we need the microwave or toaster, I simply turn off the freezer circuit for a few minutes.

    A properly installed manual transfer switch with your Coleman should work equally as well. However, as mentioned previously, some furnace circuit boards want clean power and a non inverter type generator could cause problems.
  • j-d's avatar
    j-d
    Explorer II
    He wants backup power for the Home Furnace in his Stick'N'Brick.
  • Gdetrailer wrote:
    A couple of things..

    Contractor gens like the Coleman typically supply 240/120V. This is accomplished by having two separate 120V "windings" in the gen head.

    The windings are wired in series to provide 240V and the 120V is tapped using the center point of the series wiring.

    Typically on this setup the AVR (automatic voltage regulator) is connected to only ONE of the two windings.

    When heavily loading only one side of the 120V windings which does not have AVR it will cause a voltage sag. To fix that sag you need to add a load to the opposite 120V winding (outlet)and the voltage will on both 120V windings will be corrected for the load.

    You also only get HALF the rated wattage on the 120V outlets with the typical contractor gens. The Champion on the other hand should have a switch which combines both 120V windings properly to give you all the rated wattage on the 120V only outlets (you lose the 240V when the 120V only mode is enabled).

    Additionally modern furnaces tend to have a rather picky control board and depending on the type of fan motor your furnace has it may or may not run correctly.

    If fan is a variable speed fan, it may not like the waveform, frequency or voltage variations which happen with a generator.

    The control boards also will do a system check when power is applied, part of this check is to verify that the neutral (white) and ground (green or bare) are "bonded" together. If no bond is detected (IE open between the two) the board will lockout and prevent the furnace from operating..

    The reason I mention this is some generators do not connect the neutral to the ground and some do..

    If you connect the gen through your breaker box the neutral and ground are bonded in the box and the furnace control board should be happy..

    BUT please, do not "back feed" your breaker box, it is dangerous to you and your family AND the power company linesman.

    By "back feeding" I am talking about not using a proper TRANSFER SWITCH or the proper interlock which forces the main panel breaker into the off position when powering the panel via a generator..

    Back feeding via a double male cable which is often called a "dead mans cord" is also a bad idea..

    DON'T DO IT, there IS a reason that you can not buy power cords with a male end on both ends.

    Power cords are designed with a male end to plug into a outlet and the female end there is no exposed electrical connection that you can touch..

    Install the PROPER generator INLET connector (a generator inlet connector prevents you from making contact with any live or hot pins) with the proper transfer and be safe..
    The furnace uses 12 volts. The method of AC grounding has no effect on it.
  • Google hooking up your furnace to the generator. I'm sure I recently read it had something to do with the ground. Our Champ does 240v but at 13a per leg it isn't worth doing the whole house thing. A few cords will keep the fridge and a pair of oil filled heaters going

    We do use a Champion 3500/4000 for boondocking out in the middle of no where. The noise isn't too bad if you are inside the rig but outside you want to be 50-100 feet away. (at least)

    We used it one season for battery charging, microwave and AC. It did great as long as we didn't combine the AC with the first two. Now we have solar for charging so we only use the Champ for AC.
  • A couple of things..

    Contractor gens like the Coleman typically supply 240/120V. This is accomplished by having two separate 120V "windings" in the gen head.

    The windings are wired in series to provide 240V and the 120V is tapped using the center point of the series wiring.

    Typically on this setup the AVR (automatic voltage regulator) is connected to only ONE of the two windings.

    When heavily loading only one side of the 120V windings which does not have AVR it will cause a voltage sag. To fix that sag you need to add a load to the opposite 120V winding (outlet)and the voltage will on both 120V windings will be corrected for the load.

    You also only get HALF the rated wattage on the 120V outlets with the typical contractor gens. The Champion on the other hand should have a switch which combines both 120V windings properly to give you all the rated wattage on the 120V only outlets (you lose the 240V when the 120V only mode is enabled).

    Additionally modern furnaces tend to have a rather picky control board and depending on the type of fan motor your furnace has it may or may not run correctly.

    If fan is a variable speed fan, it may not like the waveform, frequency or voltage variations which happen with a generator.

    The control boards also will do a system check when power is applied, part of this check is to verify that the neutral (white) and ground (green or bare) are "bonded" together. If no bond is detected (IE open between the two) the board will lockout and prevent the furnace from operating..

    The reason I mention this is some generators do not connect the neutral to the ground and some do..

    If you connect the gen through your breaker box the neutral and ground are bonded in the box and the furnace control board should be happy..

    BUT please, do not "back feed" your breaker box, it is dangerous to you and your family AND the power company linesman.

    By "back feeding" I am talking about not using a proper TRANSFER SWITCH or the proper interlock which forces the main panel breaker into the off position when powering the panel via a generator..

    Back feeding via a double male cable which is often called a "dead mans cord" is also a bad idea..

    DON'T DO IT, there IS a reason that you can not buy power cords with a male end on both ends.

    Power cords are designed with a male end to plug into a outlet and the female end there is no exposed electrical connection that you can touch..

    Install the PROPER generator INLET connector (a generator inlet connector prevents you from making contact with any live or hot pins) with the proper transfer and be safe..
  • That Coleman probably has multiple circuits. It doesn't produce 42 amps on a single 120v circuit. It probably has 2 separate 120v circuits that combined are 5000w. Since the 240v circuit combines the 2 120v circuits, the total 5000w is available. Champion makes a 4000w RV generator that does produce 30 amps at 120v. It has a 30 amp RV outlet. It is only 68db, and not too loud for using during the day.

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