Electrical Wiring in the Home/Motor for a heater



The motor for the fan on our unit heater went bad.  We bought a new motor and got it connected and running but the fan does not shut off after the heater is warmed up.  The motor is a d734 unit heater motor.  The motor has 1 white wire and 1 black wire.  We are trying to connect this to 2 white wires and a green wire.


The fan motor has to have something to trip it off,    like a thermostat,    for example if you had a line level thermostat in series with one side of the incoming line,    the thermostat would reach a temperature,   open up and cut power to the motor/fan,

Wiring it direct to two wires is likely not going to pickup any control circuit or device, and most likely the first motor was some type of OEM motor,         a d734 sounds like a Fasco brand motor,      and might fit,  but there is nothing inherent in the motor to shut it down at a particular temperature,          

Beware the green wire,   most green wires are supposed to be nothing more than chassis ground and has nothing to do with the control of the motor,     

I am going to need more information on what the motor is being wired to,  what those white wires connect to,  so on,        nameplate of the heater would be very helpful,    type of heater would help,  and maybe some photos would help,  but just two motor leads to   two white wires  is not enough for me to be much help,    so whatever else you can supply as far as information is the only way we can figure out what is controlling the off and on of the fan/motor

swapping the incoming wires should have no effect      AC motors don't care about which is hot and which is common,      only DC are usually polarity sensitive,.   

Send me what you can and we will go from there,  
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Electrical Wiring in the Home

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Will Babbitt


Electrical issues of all types, wiring, control, appliances, components, specialty in Electric MOTOR or APPARATUS trouble shooting, electric motors, electrical problems, single phase, three phase, DC, capacitors, elevator MG-Sets, modifications, reverse engineering, VFD Drives, single to three phase convertors. Repair of most any electrical/mechanical/electronic apparatus, OEM, AC, DC, Industrial Applications, Three phase, single phase failure mode, determining the root cause of the equipment failure BEFORE failure repeats, Antique appliances, electric motors, fans, ceiling fans, base mount fans, poor equipment performance, Modifications, habitual failures, vibration, redesign, obsolete issues, collectible items restored, rewinding. Owner of EMR Repair Inc www.emrrepair.com More information on electric motors, under Engineering/Motors Ask about any electrical or mechanical problems in the home, office, or even at your work. B2B or business to business CONSULTING I can do but it would be a much more complex issue, that would require a significant amount of time. repair@mearservice.com from there we can discuss and begin work on about anything. Industrial electric motors, controls, troubleshooting, vibration, alignment, any type of industrial or commercial electric/electrcical equipment For the home owner, renter, apartment if you have odd things going on, describe to me, photos are normally very helpful, appliances, heating and air conditioning issues, light switches, installation, DIY PROJECTS FOR THOSE NOT EDUCATED IN ELECTRICAL, we can do some things, but for safety and sanity reasons, I may refer you to a local electrician, and help you find one, help you with pricing and even speak directly with anyone you hire if you have issues,


Over thirty years with a major repair and sales company, VP of Operations, and former owner of my own specialty repair shops, MEAR Services local to Kansas City Missouri EMR Repair Inc., located in Kansas City Missouri, 2014 sold both businesses to JCI Industries, Lee's Summit Missouri wbabbitt@jciind.com Evaluation and repair of electrical/mechanical apparatus. Electrical and mechanical repairs, trouble shooting including, vibration and balance issues. About.com provides this service, and the huge costs to provide help on about any subject. They provide the servers, the people to vet the experts, costs that would be the same as operating a good sized business, They should be appreciated for what they do, the huge costs and the great help they provide for free, Electric motor questions, can be answered here but there is a dedicated category that has other experts to help and add to a solution. Other common questions, are noises in the walls, breakers tripping, devices not starting or shutting down for no apparent reason, smoke alarms buzzing, thermostat change outs, or sizing wire or needing information for a new project, but anything can be resolved, anything, with enough effort and patience, DIY, with electrical is possible, but in most cases the use of a simple ohm meter or volt meter is needed, they can be purchased at any hardware store for a few bucks. If you have smoke, or smell smoke, don't be writing me, call 911 the Fire Department has no problem looking for smoke smells, better then spraying water on a blazing fire. DO NOT GET CAUGHT INVESTIGATING AND TRAPPED IN A BASEMENT LOOKING FOR A BLOWER FAILING< As to the tip jar, it is up to you, it is appreciated, every expert spends out of pocket that I know, we spend on IP time, computer wear, printing documents, books, and of course our time, but if we prevent a $400 service call, we did well,

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10 plus years, various Technical Schools, followed by Industrial College Credit and non Credit Courses, electronics courses, experience in most any electrical apparatus, electric motors and generators, AC OR DC, fractional to above 5000HP, other electrical apparatus, slip rings, sleeve [plain] bearings, lubrication, identification-no data plate, control components, service and sales. I have continued night schools for decades, the list is extensive. I have been in the business of repairing most anything with wires or mechanical parts for decades, I have some helpful hints and directions you won't have to dig up. Or hopefully not have to pay a huge service call invoice to find.

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