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Electronics/using generator to power furnace


I purchased a 2800 watt gasoline powered generator to get me through the loss of power from hurricane Sandy.  It has 2 110 20 amp outlets & a 240 30 amp twist lock outlet. I used the 110 to power my furnace which is a high efficiency Ruud unit that is 2 years old.  I used a length of 14/2 romex with a male plug into the generator and wired the other end to the furnace (black-black & white-white & wired the ground to the bx connector on the furnace).  When I started the unit I got an error code from the led that translated to reverse polarity.  I checked my connections 3 times and they were correct.  I then reversed the wiring at the furnace (black-white & white-black) and then every thing worked ok. I was able to also run my 58" plasma tv w/amp etc., and my washer & dryer which are electronic also. I was told by the manufacturer of the generator that this unit was conventional and I should be using an inverter type unit.  Can I have your thoughts on this and if I did any damage to my appliances, furnace or tv.

Thanks for you help.

Reversing polarity probably affected the electronic control circuits on  the Rudd furnace.  

I doubt if you did any harm to the furnace of the control system elements.

My only recommendation is to be careful with full power loading.  Since a furnace has an electric motor in it the reactive power may be greater than the real power and cause some extra loading on the generator than you are expecting.  The lesson here is to load the generator light and don't expect that in all cases you will get the full power rating out of it, especially when there are motors or reactive loading on it.

Hope this will help.  


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Graduate electrical engineer with over 40 years in electronic design, manufacturing, project organization and patent review. Experience in fields of industrial and consumer electronics (audio, video, acoustics, etc.)

IEEE (Institute of Electrical and Electronics Engineers); Senior Life member AES (Audio Engineering Society), Fellow Life member

BSEE University of North Dakota

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