Hvac Question

[Scruit]

I have an old HCI Conquest 90 furnace GLUA105-E5A (W32/Y99) that has been running very loud this last year.  Have traced it to the main blower fan is rotating on the motor shaft despite the set screw being tight - once the flat of the motor shaft is not lined up with the set screw the fan is off balance and I can feel the vibration through the house.  Each time it gets loud I open it up, line the set screw back up with the flat of the motor shaft, then it's fine for some time.  Was fine for  a while but that fix lasts less and less time.  Now it slips every couple of days.

 

I tried filling the gouge in the motor shaft left by the set screw with my MIG welder and then filing it back down to the correct shape - that lasted about 3 months and now the fan has shifted off balance.

 

Two questions:

 

- New motor should fix that up, right?

- This is a replacement motor - the factor motor had holes tapped into the side for the mounting bracket but the replacement didn't.  I replaced the motor about 8 years ago and fabbed my own bracket at the time.  It's still holding strong but it'd be nice to get the proper motor so I can use the factory mounts.  Does anyone have a part# for the correct motor with the pre-tapped screw holes?

 

Motor is an Emerson K55HXSTP-7621 at 115V 60Hz 9.1A 3/4HP Frame 48Y

 

 

Edited June 24, 2013 by Scruit

[madcat6183]

Was this supposed to be in off topic?  I'll guess so, and Grapesmuggler is who you want to contact on this.

[grapesmuggler27]

Your screwed! Honestly the proper replacement is new blower motor and blower wheel. The blower wheel sounds out of round to me causing it to slip the set screw of the shaft and ruining the bearings in the motor. Can you post a picture of the original mounting bracket?

[Scruit]

It got bad enough I just had to get a new motor same as I have now. The new motor arrived yesterday. The blower wheel is relatively new after I snapped the head off the old set screw.

I'll install it tonight using my modified mount. While I have it apart I'll post a pic. Maybe next motor will be the right one!

[Scruit]

I don't understand why the flat of the motor shaft being 20deg off the set screw causes an imbalance? Unless the weight if the set screw balances out the lack of weight from the flat side of the motor shaft? I wanted to find where the set screw sits on the shaft, drill a 1/4" indentation in the shaft and use a 1/4" longer set screw for a more positive engagement, but apparently the balance is too finicky for that.

Edited June 26, 2013 by Scruit

[Scruit]

Here's the mount I modified:

 

 

Redneck-a-licious, huh?

 

The four L-brackets used to bolt to the side of the motor using pre-drilled holes.  The replacement motor had no holes and I didn't feel like drilling into the windings, do I modified the brackets to use these large universal clamps to hold the motor.  Stayed rock solid for 8 years until I disassembled it again due to the motor shaft being torn up.

 

Tonight I removed the old motor, cleaned the squirrel cage really well, installed the new motor using the same mount, and now it's running like a champ again.

[Scruit]

Removing the old motor was a bear - the damaged surface of the motor shaft wound up getting a burr in the squirrel case fan hub and I wound up having to hammer the shaft out - which of course mushroomed the fucking thing.  Eventually I removed the motor mounts and hammered the motor deeper into the hub until there was good undamaged surface on the motor shaft, then cut off the damaged section, pulled the motor back out the back.

 

All went back together great, replaced a couple of screws that stripped out the mount holes so I used the next size machine screw Took photos of the wiring diagram on the motor and posted that in the maintenance folder.

 

This is a 2-spd motor not a 3-spd motor, but the furnace wiring diagram show the lo-speed wire is not used so I'm not gonna cry myself to sleep over it.  It's running, it's quiet and it's like a fridge in here.  Score.

[grapesmuggler27]

Here's the mount I modified:

 

 

Redneck-a-licious, huh?

 

The four L-brackets used to bolt to the side of the motor using pre-drilled holes.  The replacement motor had no holes and I didn't feel like drilling into the windings, do I modified the brackets to use these large universal clamps to hold the motor.  Stayed rock solid for 8 years until I disassembled it again due to the motor shaft being torn up.

 

Tonight I removed the old motor, cleaned the squirrel cage really well, installed the new motor using the same mount, and now it's running like a champ again.

And this folks is why you call a professional.

[2talltim]

And this folks is why you call a professional.

I've got my horror story too, I too replaced my motor took the old one to Grainger and got a exact match, all was good till i tried to take the blade off the old motor when I dropped it. Fucked the balance all up. Took me not exaggerating 6 hrs to bend it back into balance using trial and error, even then it had a slight vibration to it. Well eventually it went away then about 2 years later I decided to blow the furnace out. The vibration returned come to find out the dust on the blades was balancing it. .lol. I figured it would eventually east the bearing up on the new motor but that was 7 years ago, I just lightly clean it now. Edited June 27, 2013 by 2talltim

[Scruit]

And this folks is why you call a professional.

 

 

Uh huh.  Been like that 8 years with no problems.  The "professional" I called out at the time told me the he coudn't get the correct motor and said he'd only sell me a new furnace for $4k, not fix mine.  $10 later I'm, back up and running and this mount has held, and continues to hold, 100% with no problems.

 

In fact, over the  13 years I've been at this house I've called a "professional" out a couple times and only once has the call gone well.  One time a guy spent 2 hours over 3 visits trying to diagnose the furnace not keeping a flame.   Turned out to be abad vacuum switch that I diagnosed and replaced myself. 

 

Another time a "professional" came out to check a no-cool situation and told me it was illegal for him to fill up my freon, despite him saying the only issue was the freon was low and that there is no evidence or history of this old A/C ever leaking before.  He tried to tell me he could only sell me a new A/C with new furnace also becuase no new AC would work with my furnace.  He asked for $10k and asked if he "should schedule an install for tomorrow?"   I told him I knew that he's allowed to charge a system - in this case all I'm asking for is a blow&go, not a new a/c.     I sent him on his way and called ANOTHER professional out and this guy recommended a recharge and a service of the A/C.  He took the evap outside, cleaned it up nice and charged me back up, it was only a couple hundred bucks.

 

Not saying all professionals are like that, obviously, but simply saying "call a professional" has not worked for me in the past. Maybe it's just my badk luck to randomly pick the worst "professionals" in my area

 

I WOULD really like to hear what it is about this motor mount (that has held for 8 years and is still going strong) is problematic for you?    

 

And what was I supposed to do when the professional I called out  told me the part was obsolete and not available any more, and told me the only course of action was to spend thousands of dollars on a new furnace?  You can say "get a second opinion" but that means I'm assuming the first guy is flat out lying about the availability of the part.

 

Finally: Is the correct motor still available? 

Edited June 27, 2013 by Scruit

[grapesmuggler27]

Yeah the correct motor is avail. Conquest is made by rheem, rheem still uses that silly motor to this day. You should have to replace any blower motor more then once. The poblem with the bands is all the pressure is in the center and not spread out through the whole frame like the oem motor, while it may of lasted 8 your going to be in the same boat a few years down the road, the torque that motor almakes is now on those bands in the center of the motor vice on the end of the motor frame like oem. Its hard to really explain over the internts as I have a hard time explaining via typing. But a true professional would of got you that motor and had all the proper tools to change the motor and not try to sell you something You don't need.

All in all you fix will get you by for a time but I see the same problem happening again down the road. Btw did you replace the capacitor as well??

[Scruit]

Yeah the correct motor is avail. Conquest is made by rheem, rheem still uses that silly motor to this day. You should have to replace any blower motor more then once. The poblem with the bands is all the pressure is in the center and not spread out through the whole frame like the oem motor, while it may of lasted 8 your going to be in the same boat a few years down the road, the torque that motor almakes is now on those bands in the center of the motor vice on the end of the motor frame like oem. Its hard to really explain over the internts as I have a hard time explaining via typing. But a true professional would of got you that motor and had all the proper tools to change the motor and not try to sell you something You don't need.

All in all you fix will get you by for a time but I see the same problem happening again down the road. Btw did you replace the capacitor as well??

 

The capacitor is new.  I kept the squirrel cage fan as it's still balanced and the hub is in good shape.

 

The reason the last motor failed is the set screw came loose and was able to start cutting a gouge into the motor shaft.  I didn't use loctite last time.  I did this time.  The mount has never been the problem, unless the mount is contributing to the set screw loosening in some way.

 

Are the 4 motor mounts still available too?  

 

Do you accept that it is difficult for a homeowner to handle a situation where they call a professional and they are told something that is is not correct?  How do you advise we handle that kind of thing?  If I'd followed the professional's advice I'd have shelled out $4k on a new furnace I didn't need.  Just keep calling them out until I get one that can do the fix I need?

[grapesmuggler27]

The capacitor is new.  I kept the squirrel cage fan as it's still balanced and the hub is in good shape.

 

The reason the last motor failed is the set screw came loose and was able to start cutting a gouge into the motor shaft.  I didn't use loctite last time.  I did this time.  The mount has never been the problem, unless the mount is contributing to the set screw loosening in some way.

 

Are the 4 motor mounts still available too?  

 

Do you accept that it is difficult for a homeowner to handle a situation where they call a professional and they are told something that is is not correct?  How do you advise we handle that kind of thing?  If I'd followed the professional's advice I'd have shelled out $4k on a new furnace I didn't need.  Just keep calling them out until I get one that can do the fix I need?

Call me 614-381-8413

[standout]

Every time I've called a "professional" they recommend a new system that cost umpteen thousand dollars. Then I found grape that is a serious pro and has fixed me up each time instead of just saying replace it.

[madcat6183]

Every time I've called a "professional" they recommend a new system that cost umpteen thousand dollars. Then I found grape that is a serious pro and has fixed me up each time instead of just saying replace it.

But did he touch your pepe?  Cuz he always touches mine when I see him.

[grapesmuggler27]

I do understand your frustration. But let me make myself clear I'm a professional hvac tech no a professional salesman. But can you understand you have a bottom of the barrel brand furnace that when a service company repairs a blower its 500-700 and to install a comompairabke furnace is around 2400 so a repair is 25% of what a new unit is that maybe the person there was trying to give you options. I don't know the age but anytime a repair is 25% of a replacement I give the customer the option while I'm at work if the system is older then 12-15 years old.

[Scruit]

I do understand your frustration. But let me make myself clear I'm a professional hvac tech no a professional salesman. But can you understand you have a bottom of the barrel brand furnace that when a service company repairs a blower its 500-700 and to install a comompairabke furnace is around 2400 so a repair is 25% of what a new unit is that maybe the person there was trying to give you options. I don't know the age but anytime a repair is 25% of a replacement I give the customer the option while I'm at work if the system is older then 12-15 years old.

 

I understand being given options - that's fair enough.  In both cases (Motor replacement in furnace, and A/C recharge) the HVAC techs told me my ONLY option was to replace the systems.   The furnace, as you know, ran fine for many years after the fix (longer on my mounts than the factory mounts) - and the A/C ran fine for 3 more years until we chose to replace it with a modern unit due to running costs (It's was a 1970's unit)  Stands to reason that not being given the option to repair was not great advice.

 

I realize this is not a top-end furnace, but you said it yourself - 500-700 for a new motor from a HVAC tech.  I replaced this motor last time for $120.  This time was $170 because thew local places refused to sell to me so I ordered online instead and had to pay shipping.  Both times was less than an hour of install work for me.  I understand the HVAC tech needs to make a living, and I would have jumped at the chance to have a HVAC tech do this work instead even at 300-400 - but I was not given the repair option by the guy who came out, so I opted for the $120 solution rather than the $4k solution. 

 

Maybe what I need to do is buy the 4 motor mounts now and set them on the furnace - next time the motor goes out (whether it be 8 years or 8 weeks from now) I'll insist on the replacement motor and I'll have the mounts in case they are obsolete parts by then.  Then the unit can be reassembled back to factory specs.

 

As the new motor is running like a champ I'm not really inclined to replace it again immediately - it won't hurt anything (other than the motor itself and the SCF) to wait until this motor has completed its service life.  The furnace is 14 years old right now, so maybe by then it'll make sense to replace the entire unit.

 

Please don't think I'm ragging on HVAC guys.  We've all had good and bad experiences with different service providers whether it's getting cars fixed, roofing work done etc.  My problem is that I like to figure things out myself so I successfully troubleshoot and correct the vast majority of the problems that a normal person would call for a service tech for.  By the time I give up and call in someone, it's usually a doozy of a problem that half the time they can't even help me with, or it is complex enough that they don't want to get involved in it.  (distinctly different from "I've had a go at fixing it and made it ten times worse so they don't want to inherit the mess" - which I totally understand)

[grapesmuggler27]

Like I said your strap idea will get it by there is just a lot of extra unneeded extra stress on the motor on start up. The price is why I do some side work the same $600 fix I do for actual price of part and a little for labor

[Scruit]

Like I said your strap idea will get it by there is just a lot of extra unneeded extra stress on the motor on start up. The price is why I do some side work the same $600 fix I do for actual price of part and a little for labor

 

I'm in Delaware - if this gives me a moment's trouble from now on I'll have you fix me up right.    Grape > < Scruit

Edited June 27, 2013 by Scruit

[Scruit]

 there is just a lot of extra unneeded extra stress on the motor on start up.

 

That makes a bunch of sense...  The mount I used is too strong causing the motor to torque too hard against the SQF, putting all the force on the tip of the set screw.  That explains why the last motor only lasted 8 years.

 

So, continuing that though... the factory mount has some flex, right?  That flex absorbs the initial startup torque and reduces the stress on the tip of the set screw?

 

Ok, so now I know that the next time the SQF slips on the motor shaft, the permanent fix is to restore to factory configuration. 

[Scruit]

That makes a bunch of sense...  The mount I used is too strong causing the motor to torque too hard against the SQF, putting all the force on the tip of the set screw, which over time starts to cut into the motor shaft allowing it to rotate. .  That explains why the last motor only lasted 8 years.

 

So, continuing that though... the factory mount has some flex, right?  That flex absorbs the initial startup torque and reduces the stress on the tip of the set screw?

 

Ok, so now I know that the next time the SQF slips on the motor shaft, the permanent fix is to restore to factory configuration. 

[grapesmuggler27]

Yeah that's kinda what I was explaining in my post this morning before I had my caffeine. The oem mount and motor work together hand and hand to relieve the torque at start up. All your torque is in the middle on the bands and not on the whole frame like the oem motor and mounts were designed. Btw I've never ever ever put loc tight on any set screw for any blower motor or condenser fan motor. You band idea will work but isn't the ideal fix, hence why I said that's why you let professionals do your repairs. Also technically your motor only lasted 7 years from when it started slipping. Either way 2 blowers in 14 is still a rare occurance.

[madcat6183]

Joe, serious question, with the kid on the way, should I get the vents/returns cleaned and like ionized or whatever they to during cleaning?  I wanted to have everything done before we haev the kiddo, 1.5 months out.

I know you told me it's a good idea to get done, does your company do it?  What all would I have to do?  Obviously I can't be home all day, except weekends, and we normally have cats in the basement, dog in house, so they would have to go bye bye for the day or however long it takes.  Dog is easier than cats naturally.

 

Also, I need to "bomb" the house soon, so I was thinking of bombing it like Friday night, heading to Mansfield, then coming back saturday morning for them to clean the vents/returns etc.

 

Is this wise to do.  I change filters regularly and when I have the kid I will buy the best filter I can, and probably change every 30-45 days instead of 45-60 or is it 90, I forget my thermostat has a reminder and I write the date on teh filter a few places.  Either way, figure I should change them more when hes born anwyays.

[grapesmuggler27]

It never hurts to have them cleaned and disinfected. My company does not do it and neither do I

[madcat6183]

Looks like there's quite a few that do and I know we get coupons in the paper sometimes.  I'll see what's out there this weekend.