Heating, Air Conditioning, Fridge, HVAC/Furnace Blower



I have a couple questions regarding my furnace blower and possible replacement of it.

I have a carrier 52mcb100-1 gas furnace. According to what I can find out it has a 1/2hp 4 speed 115v 1075rpm motor. It is a single stage furnace with a PSC motor.

I was looking at a couple things. I want to leave my blower motor on continuous to help balance the temperatures between the 1st and 2nd floor, however with the current motor it uses a bunch of electricity.

Looking on the net I found the evergreen motor. It is a ECM motor that claims it can replace older PSC motors, and save a good amount of electricity. Here is a link; http://www.genteqcomfort.com/EnergyEfficient/theMotorMatters.aspx

Also, the motor I was looking at to replace my current motor; http://www.comfortgurus.com/product_info.php/products_id/3645

Last question; I have been experimenting with leaving my furnace blower fan "ON" continuous instead of "AUTO" and the strange thing is, when ever the furnace calls for heat the fan shuts off for about 1 minute and furnace ramps up comes on with heat, then when the furnace no longer calls for heat the fan stays on. Is this normal?

Thank You and have a great day,

Leaving the fan on all the time is a good idea to keep the air moving and even temps.  You just need to remember to check and change your air filter more often.

I was attempting to look up your unit, and I can not get the model number you gave me to come up.  It is likely the fan turns off to allow the heat exchanger to warm up before the fan turns on.  I would guess the controls turn off the fan on a call for heating.

The motor you are looking at is similar to that of an x13 motor.  I would not put an x13 motor in my unit.  Recently, I have changed out several of the x13 motors that have failed, som of which are only a couple of years old, one that lasted just a few months.   I do not install a new x13's, but I convert the unit over to a PSC motor that I know will be trouble free for years to come.  I have all the parts in my garage ready for the day when my x13 finally craps out.  The x13 run between $300-$800.  I can get the all parts for to convert for about $120.  Talking to the vendor, they concede that most of the x13 motors they sell are warranty claims.  The manager at the vendor did tell me there is a better motor that seems to be able to handle the power spikes better, but I am not going to find out.

You need to be aware that many times there is no warranty with electrical parts when purchased over the internet. I have heard of this problem on more then once...


Heating, Air Conditioning, Fridge, HVAC

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Craig HVAC Expert


I have been in the HVAC field for the past 18 years. I can help with most HVAC questions. I work on commerical buildings for the most part, and have yet to find anything I could not troubleshoot and repair, when repairable. I work on small 1 ton units to a 2500 ton chiller. Troubleshoot air flow, elect, and control problems. I attend regular classes to keep up with the latest and greatest.


I work on commerical sites, hospitals, gov't buildings. I can troubleshoot just about anything in the HVAC business.

5 years trade school, VFD training classes, Liebert factory training, some York and Trane factory training.

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