Electrical Wiring in the Home/Attic Fan

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Question
Hi! About 14 months ago my attic fan started to make noise so I decided to get it replaced before it broke. Before this noise never had a problem in the 10 years I owned this house. Called my electrician and we decided to just replace the motor. So I found motor on line and he replaced it. Ran while he was here but then we set thermostat to 80-90 and it went off. Well it got hot and never went back on. Called back electrician and he took out motor and I sent it back and got a new one. Again the same thing happened. So a few weeks ago he decided to buy the entire kit and changed the wires and thermostat. Well again it ran while he was here the entire day because it was warm but went off and again never went back on. Checked the breaker and all is fine and light in attic still on. I have spent over $300 and still no attic fan. What could this be? My electrician thinks I have ghosts??
Thank you for your time.

Answer
I think you need a new electrician,    this is very similiar to a ceiling fan qeustion  you can read on my previous answers list,      


It is likely the same problem     when it is off and won't come on,  it could be the internal motor thermal opened up   if this in a very hot attic it might take a long time for the internal thermal to reset with the ambient air in the attic being very warm,   they are crappy devices and often will trip one or two times and then they are done,   making the motor useless,    

But more likely  is the voltage,     the electrician should measure the voltage and the values when the fan wont start      if no voltage then test at the incoming and load side of the switch/stat    find out where the voltage is opening up,  

IF there is voltage    what is it,    voltages change in most homes   most are not aware ans assume the voltage levels are steady     not often      if the voltage is high or low,   

That is the more likely problem     a quick check of amperage is not going to show up if the voltage is at max tolerance and then gets over tolerance later in the day   

The combination of low or high voltage may be tripping that thermal out,   and if it is an internet motor the chances are the motor thermal is even cheaper made and less reliable,   

Most assume a motor burns out, when they can open up  and not run,    the only way to confirm the motor burnt is if the motor has slots where you can see black wire and it will have a strong odor of burnt insulation,   

If the motor is burning completely up,   then it is either a bad batch of motors,  or voltage   but since you replaced everything,     it about has to be a combination of voltage and heat in the attic,       

The breaker never tripping   tells me the motor did not burn but got hot and opened up,   

But you have to confirm the voltage and the value if it stops,   your house could have HAD steady voltage,  but a loose or corrision on a connection outside might be a problem causing varying voltage levels,       

You need to know not only the current for a short check   but the voltage AT THE MOTOR  is it low , high or none?

The length of the wire run may be minimal in size and if the voltage NOW fluctuates  which can happen,   combined with the heat the wire and motor are in,  is likely your problem   this is something a good electrician should be able to trace out and find the source of the problem

I have also seen clamp on meters not calibrated and the amps at the spitter will be false

A loose wire nut in a junction to the motor could cause problems,   a voltage drop,  

No hum  no attempt to start,   no tripped breaker  =open circuit,     if the motor burnt the breaker should pick up the high current at that time,   is the breaker large for the amps,   for example  a 30 amp breaker and a 5 amp motor?

Breakers go bad   not often unless tripped a lot of used as a switch,  but they can go bad, just sitting there,   and the size for a motor is a huge consideration,     actually you need a fuse holder and slow blow fuses to protect the motor,   not a huge cost and might save the motor until you find the voltage problem.    breakers protect wire    not devices,   and often the sizing is off to the high side adding to the lack of protection they are too slow in tripping,    motor circuits should be protected by fuses,    or a specialty breaker designed for motors,        the high start up current is why the breakers are often mis sized      

You need someone with troubleshooting experience,  a look at the voltage prior to,  and during operation,    and measurements at different times of the day        

From your description,   this sounds like a voltage problem somewhere on the way to the motor and switch  be it utility   be it a loose connection  be it too small of wire  for the run,       right now you need to know the open circuit voltage where the motor will connect   again if this is an attic fan and the attic is very warm    most likely either the temperatures it is operating in,  could be the entire problem   or more likely it is a voltage value,   an intermitten change in the supply level of the voltage     I have seen voltages as high as 140 up in homes,   a utility problem that was not there for years, but they changed something,   a tap is off,   more power is being used in the entire feed and the voltage is low,       

You need a troubleshooter who has experince with motors, and they should have no problem finding the issues   or issue    voltage is the number one suspect at this point,     let me know what you find   voltage levels so on,,,,,,,
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Will Babbitt

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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,

Experience

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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Former IBEW, EASA, IEEE, UL, ..............

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SEE ELECTRIC MOTOR CATEGORY

Education/Credentials
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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Federal Government, National Weather Service, NOAA, Commercial Power Plants, Major Vehicle Manufacturers, Printers, Other industrial and Commercial Businesses

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