variable speed motor on york heater is defective

hello, im new to the forum found it while browsing for info online...
the blower motor on my York heater has died... i did some troubleshooting and also had a tech from a company come out and he also determined the motor is bad... my blower seems to be fine it spins freely just the motor never kicks on.... they are asking $1600 for repair....and recommending i just get a new heating unit which would be $2500-3000, i want to try to repair it myself with an equavalent motor... the specs on the motor are;

Variable speed
1 HP
120 volt
11 amp
60 Hz
spins CW from lead side

the heating unit is a gas York unit model p2mpu20n0b001a, installed in 1995,
it works fine the gas kicks on, flames start to burn, small exhaust fan turns on but blower never starts spinning, checked fuse its fine, there is an LED on the power supply which blinks green at a slow rate which means its fine...
the only thing i have not checked is the capacitor which i have read on the forum here to check, i do not see it anywhere so im not sure if this unit has one, i have not started taking it apart yet....

my questions are where could i purchase a comparable motor and if i do just get the motor would i be able to attach it to the blower...? any suggestions would ge greatly appreciated... happy holidays!

Welcome D-A-V-E:
You might try to contact York directly who could steer you to a local distributor. Many of the variable speed fan motors are 'direct current' and are extremely expensive. I'm sure you would not have any trouble installing a new one. One convenience point; you may need a long tee-handle allen wrench to remove and replace the screw in the closed side of the blower. You will find that screw where there is a dent in one of the vanes near the closed side.
Another thought is to visit a local dealer and see if he has a used motor that still works.
Or you could take the old motor to a Heating, ventilating, air conditioning; refrigeration supply store for a new one.
If the unit is not over 12 years old, I would recommend repari; if it is over 20 years old it is time for a new one.
Glenn

One more thought, you might take the motor to an electric motor shop for repair or rewinding. When we get up to 1 hp they are worth rebuilding.
Glenn

thanks for the advice....

well i was able to take it apart, suprisingly the motor seperated from the blower fan easily, i took some pictures of it i will post later, it looks like its a GE motor but there is a date code on it of 03/27/03 or at least it looks like a date code which means that is not the original motor since my heat unit was installed in 1995.... ive only been living in this house for 1 year 10 months....

so i am going to see if a can find a local electronic shop and see what they say....

still working on this, i had the guy that repairs electric motors look at it and the motor seems to be fine, however there is a control unit that is attached to the back of the motor with 2 screws and the motor plugs into it.... it actually looks like its part of the motor but its not... when you take the back off there are several caps and other electrical components inside attached to a circuit board and you can clearly see a burn mark by what seems to look like a diode... it has a part # of SG379 on it.... so im pretty sure that is the problem.... so basically im doing some parts hunting, see if i can find anything online...

Hello D-A-V-E:
It will be nice if you can match the diode (transistor, resistor or whatever it is) but the service men usually replace the whole circut board.
Sounds like you are doing a good job though; keep up the good work.
Happy New Year
Glenn

well looks like im a bit SOL so far....

the failed component is actually a thermistor however i dont know the value of it and the only number on it is SG379, i was talking to a friend of mine who used to repair circuit boards and he said if that thermistor failed there may also be other components that failed on the circuit board.... so even if i were to solder on another one it may or may not work...

i contacted a couple local motor repair GE places, however they said they do not work on the residential motors for furnaces nor do they have parts for them and that i would have to contact York...

so i emailed a few york places for a price quote but since its a holiday weekend they are probably closed.... so im still hunting for parts... here are pictures of the motor and circuit board...

motor attached to blower
motor with control circuit on the back of it
motor close up picture
another close up pic
control circuit detached from motor bottom of circuit shows burn mark
control circuit top view thermistor is the small round disk shape in the center
picture showing how control circuit detaches from motor

any suggestions would be greatly appreciated...

Motor shops usually don't want to work on 'fractional horse-power' motors but since yours is a one horse, I would think there would be willing to sell parts for it.
Another thing you might try is taking the circut board to Radio Shack who can test it and sell you many of the small parts. I admire your tenacity; you've really stayed with this one.
Happy New Year
Glenn

sorry for the really really really late response to this... but I ended up finding a store that sold me the motor and the control circuit for about $1000 but i pretty much had no choice, its the only place that would sell it to me, and my house got down to like 40 degrees, i couldnt get it from York since they only sell to people who have a license to work on AC/heating systems.... and they told me the control circuit only came with the motor....

so i installed it and its been working fine....

about 2 weeks after i installed it some guy emailed me from craigslist, since i posted on the wanted adds there, and he said he could get me just the control circuit for about $400 but it was a little late....

so basically if i ever replace this heating system i will make sure my next one will have a single speed blower motor which costs about $100...... sure the variable speed motor may not be as loud and supposedly uses less electricity but if you have to replace it every 4 to5 years because a $10 electrical component fails then its a waste of money....

DAVE
I'm having your problem with same GE variable speed motor on Trane furnace. What looks like a capacitor but you say is a thermistor is bad and I cannot find a replacement. By any chance did you find a better source than Craig's list for the controller or the replacement component part? You are correct. This is really frustrating!
Thanks from another Dave

I have a York HVAC system. Yesterday the blower started turning off after a few seconds of running, then turning back on and off repeatedly. I took apart the unit and cleaned it and put it back in (what a pain in the...). It ran ok for a few hours, but then started doing the same thing again; turning off after less than a minute of running and attempting to restart repeatedly.

This happens whether trying to heat or cool and doesn't change no matter what setting the fan is on (auto or on all the time). The motor also gets fairly hot to the touch.

Is this an indication that the blower motor is bad or going bad? If not, what else could it be?

(Sorry to thread jack, but I'm new here and don't have permission to create a new thread yet).

Thanks!!!

Jason

Welcome Jason:
Most of the variable speed motors on modern heating and a/c equipment are powered by direct current (DC). There is no way to know if your motor is going bad or a fan control is failing but the continous starting will heat any motor up. This motor is too expensive to dilly-dally around with (over $400); I would get a York dealer out there, pronto.
Glenn

Thanks for the reply! The motor stays quite hot when it's wired to the system, even if not running (I turned the system off by the tstat). If a fan control is failing, would that be located on the sytem board? The board is clean of any burnt marks.

Jason

I had the same problem with the burned out SG379 part. I found the part at amazingkeys.com. I received it and soldered it in and it worked perfectly! That saved me over $1000 and I'm happy.

d-a-v-e
I am having problem finding parts for my variable motor.After seeing your pictures of your motor you have the parts that I need.I had a power surge and it blew the capacitors.If you still have the circuit board with the capacitors on it,I would concider buying it from you.
Thanks
Mac-m

I had exactly the same problem with my GE ECM, 1 hp on my Bryant unit. I didn't take the time to find just the thermistor SG 379, I was happy to find the ECM from Hawthorne HAVC in Wauconda, Il 60084 for $340 on a 10 degree day. The SG379 was burnt. I'm going to find some somewhere for spares, just in case. If your looking for one sometime after 1/26/09, you can contact me - I'll prob have some after then that I will pass on to others in need.

John

The big NTC thermistor (SG379) is a 1 ohm inrush current limiter. The board that this part is located on is a DC power supply for the motor. It contains a full wave bridge rectifier and large filter caps. The Thermistor has a resistance of 1 ohm at room temp. As the motor starts to draw current, the thermistor heats up and the resistance goes down.

I have 2 furnaces in my house with the ECM motors. One of them burned the SG379 last week. I jumpered it wit a piece of wire until I get a chance to replace the part.

I am replacing mine with part number 495-2123-ND from Digikey dot com Cost was 6 bucks each plus $2 for first class mail.

The other blue discs on the board are MOV (Metal Oxide Varistors) They are the same component that are inside surge supressor power strips. They work by becoming a short circiut beyond a certain voltage. They "sacrifice" themselves to dissapate the surge. I do not have a part number for these.

As for the ebay guy, 100 bucks for a 6 dollar part is just wrong.

Enjoy

Jim

flatfour said:

The big NTC thermistor (SG379) is a 1 ohm inrush current limiter. The board that this part is located on is a DC power supply for the motor. It contains a full wave bridge rectifier and large filter caps. The Thermistor has a resistance of 1 ohm at room temp. As the motor starts to draw current, the thermistor heats up and the resistance goes down.

I have 2 furnaces in my house with the ECM motors. One of them burned the SG379 last week. I jumpered it wit a piece of wire until I get a chance to replace the part.

I am replacing mine with part number 495-2123-ND from Digikey dot com Cost was 6 bucks each plus $2 for first class mail.

The other blue discs on the board are MOV (Metal Oxide Varistors) They are the same component that are inside surge supressor power strips. They work by becoming a short circiut beyond a certain voltage. They "sacrifice" themselves to dissapate the surge. I do not have a part number for these.

As for the ebay guy, 100 bucks for a 6 dollar part is just wrong.

Enjoy

Jim

Click to expand...

Thanks for adding this information to the thread. I can see that this is an ongoing source of rip off for consumers - $400 for a $10 circuit board and $1000 for a $100 motor, for instance. I am looking at a new furnace and I think I'll pass on the ECM motor, even though it would be an electricity saver.

I recently rebuilt my furnace's electronic air cleaner unit by just buying a few inexpensive new components from an electronic supply house. Fortunately the instruction manual had a schematic with all the component values listed.

I have a GE motor like yours but it is a 1/2 hp not a 1 horespower. GE model 5SME39HL0137. It has 1-16 pin plug and 1-5 pin plug

I have to say thanks to the people that on this page!! THANKS!!!
Sg379: A simple replacement just for a few $$$ not hundreds. This unit is up and working great. Thanks again. Donald