Bryant 693 Split System Heat Pump - Fan Failure

[LSPAN2K]

Suddenly the inside unit fan will not come on. Here is what I have discovered so far:

1. Digital thermostat has fresh batteries and appears to be functioning.
   
2. All breakers are on, not tripped or tripping.
   
3. Filter is clean.
   
4. When selecting heating or cooling, the outside unit cuts on normally.
   
   1. 
      
   2. The outside unit is clean.
      
   3. The outisde unit is not iced up.
      
   4. The coil inside the air handler chills down properly.
      
   5. The coil is clean.
      
   6. When selecting heating or cooling, the inside unit hums, but the fan doesn't activate. Same for when "FAN - ON" is selected at the thermostat.
      
   7. I replaced the starter capacitor with one of the same exact specs. It uses a single capacitor.
      
   8. Tried to restart unit, no change.
      I have a decent Sperry Snap 6 VOM, and also a Wiggy. Plenty of hand tools, just not knowledge of HVAC.
      Upon checking the wiring, I found in the control wiring an "orphan" wire, the lone green wire at about 3 o'clock. It runs with it's mates back to the outside unit. I could not tell if it had broke off from the other green wire that was wire-nutted to a grey, heavier gauge wire that's at 12 o'clock. Possible the wire broke off due to vibration, cat swinging on wires? I looked for the broken off piece of bare copper (if any) but didn't see one.
      
      I also took a pic of the back of the wiring cavity, showing these items  - I am guessing they are temperature sensors of some variety.
      
      And finally the blower unit and starter capacitor itself:
      
      If you can offer any advice on how to proceed from here, I would sure appreciate it.

[RegUS_PatOff]

I'm no expert, but if you would carefully untwist the D connector to see if there is (3) wires ...

( I wouldn't think so...)

If the inside unit (Fan) hums, it may be locked-up (bearing?)

Can you turn the Fan Motor by hand ?

[LSPAN2K]

I can't believe I left that out: Yes, the fan turns free and smooth. It's also fairly clean.

I looked for the wire booger that should have been in the wire nut with the grey and other green wire, but I didn't see it, although it is a small piece of wire in a dark basement work area.... and not to mention my stellar eyesight.

[RegUS_PatOff]

What part "hums", the Motor or one of the Relays ?

 

[LSPAN2K]

I believe the sound is coming from the capacitor and resonating off the fan housing. It's not coming from the control wiring cavity, but from the fan area.

This hum was there with both the original and replacement capacitor.

 Sorry, getting tired and leaving out details.

 

[dkpd1581]

On a call for Fan with the motor humming try carefully to rotate the wheel.  Your bearings may be bad yet able to turn when the motor is de-energized; however, when energized the stator and rotor may lock up together and keep the wheel from spinning.

Look carefully and you will see that you have 2 pairs of 18/8 control wires in the cabinet.  The pair with the loose green wire is most likely only using a Red for 24 VAC to the outdoor unit, and Orange for reversing valve at outdoor unit, Yellow for call of the contactor at outdoor unit, and some color for common to the other side of the contactor and control board at the outdoor unit.  Green would not be used as it is typically reserved for Indoor Blower (ie fan) and that is NOT at the outdoor unit.

[LSPAN2K]

Ah, so perhaps energize the system and then carefully prod the squirrel cage with something to see if starts to go, or is locked up?

 

And if locked up, save the capacitor and pick up a new motor/fan assembly?

[dkpd1581]

Exactly

[LSPAN2K]

Cool. For my own short memory, I will tag the orphan green wires as "not used" and do the prodding-o-the-energized-fan test. I will follow up with you guys tomorrow. What a cool site, glad I found y'all.

 

CORRECTION: Orphaned green WIRE. Not wires. I understand the other green is in use, as you said. Whew!

[LSPAN2K]

I came home prepared to do the nudge test on the energized blower motor, and when I thre the breaker at the air handler, the thing came on and ran OK... I let it run for about 30 minutes, then switched it off at the thermostat. After cutting it off at the thermostat, it took about two minutes or so for the fan to stop, but it did.

I waited a few minutes and then tried it again, and it worked fine, again.

I just tried it with the heat, and it also worked. What's up with this? Do I have some self-healing motor? Don't get me wrong, I'm glad it's decided to start working again, but is this the beginning of a chronic off-and-on running problem?

 

[LSPAN2K]

There is a new twist on the ongoing saga of my blower: For two days the system has worked flawlessly, until 6:30 am this morning, the outside unit came on, but the fan did not start. I immediatley went to the basement and opened the air handler unit, prodded the fan, it moved freely. I smacked the motor, nothing happened. I then used a wooden dowel to poke/prod everything in turn, and when I tapped a small black box (shown in my 1st picture, at 6 0'clock, has a blue wire with a red boot and a black wire with a blue boot connected to it...) the fan magically started up.

Is that a relay? Could that be sticking, and if so, I am guessing I can get one of those at an electrical supply house?

Thanks again!

[RegUS_PatOff]

yes

[LSPAN2K]

I ordered a replacement control board (CES0130003-01) from Shorty's HVAC Supply.

I did search the virtual shelves of the venerable Samurai's store but found none, so I had to venture elsewhere. $42.00 shipped.

I should have it in by Wednesday. Thanks for y'all's input!