Log in

View Full Version : Bryant model 394 dac


blstrabbit
Dec 9, 2009, 03:21 PM
I honestly have no clue what I am doing and if I could I would call a professional, but as a single mom with 5 children right before christmas it is unfortunately not an option so every piece of advice would be appreciated.
I have an older bryant furnace without diagnostic lights. I am not sure when it was built, but the model number is 394dac000100. Last year it stopped working and I replaced the fan limit control. Afterwards I did not have any further problems. This year, the blower motor is acting up. It started humming and the blower would not come on. At first it was working fine when I spun the wheel and applied power to the unit by flipping the switch (capacitor?). I left the fan option on the upstairs thermostat on "on" in the hopes to get it going until I can figure out what to do, but it never stayed on for longer than a few hours. The fan was easy to move and spun freely at first. Now I noticed that when trying to turn the fan while it is humming it seems not stuck but rather as if the motor is poled wrong. I thought that I may have mixed up the leads at the fan switch when I replaced the thing so I turned them around (I figured it's not working anyway so why not try). For a weekend it even started up by itself insync with the firing operation. Now we are back to it working when it wants to and doing nothing if it doesn't feel like it. I am assuming the motor is shot - please correct me if I'm wrong. Where can I get a decently priced replacement motor preferably in the Denver area (Bryant is asking almost $500). I will have to put this in myself so any tips would be great. It's reallly cold here...
Thanks!

KISS
Dec 9, 2009, 06:23 PM
Well, your first symptom sounds definitely like a capacitor. Operating it for so long in the bad capacitor mode may have blown the motor.

If he cost of a cap bothers you, you can sometimes get them surplus for a few dollars.

Now you will have to replace the motor and capacitor at the same time.

If you have a p/n you can always try eBay.

Evergreen makes a replacement motor, Introducing Evergreen ECM Motors | ComfortGurus.com :: The Comfort Guru's Blog (http://comfortgurus.blogspot.com/2009/09/introducing-evergreen-ecm-motors.html). Looks like the cost is about $290-$350

Replacing it will be much more difficult, but the energy savings might be worth it.

I'd have to look to see if I can find a schematic for the furnace.

You need access to 120 or 240, 24 VAC that runs the fan, and a 24 V tap for each speed, heat/cool

It might be too difficult to install, though.

KC13
Dec 9, 2009, 08:16 PM
A dealer would likely use O.E.M. motors, which are rather pricey. There's lots of aftermarket options. Seek out TOTALINE part# P257-8587 for 1/2 HP or P257-8589 for 3/4 HP. Be sure to install a new matching capacitor.

blstrabbit
Dec 14, 2009, 04:10 PM
Thank you for your replies. Sorry I couldn't come back earlier - problems always occur in clusters. Now I just wish I could locate the capacitor. It is not mounted on the housing. Could it be externally? I also do not see a brown wire to follow from the motor.
The ECM motor looks interesting, but I think I'm in waaaay over my head. Taking one out and putting same in is one thing. This is a completely different story ;-) Am I correct that I will need a 115v, 60cy, 1075 rpm, 1/3 hp, 2-speed motor?

KISS
Dec 14, 2009, 08:22 PM
Follow all the wires. How many are there and what colors are they?

KC13
Dec 15, 2009, 04:16 AM
The OEM motor on your furnace may not use a capacitor. Other than an ECM motor (Evergreen, etc.), any replacement will require you to add one. Unfortunately, this is not an easy D.I.Y. project.

carlosjuan
Nov 24, 2011, 08:05 AM
Why my furnace won't shut off

carlosjuan
Nov 24, 2011, 08:09 AM
What is the purpose of hi limit senseror