jcureton

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

glennjanie

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

jcureton

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

Bob Reynolds

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.

mac-m

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

gidzhome

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

flatfour

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

travelover

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.

Lupe

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

donaldr362

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