A short story of air handler modifications and an expensive wiring fail.

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acammer

Burning Hunk
Nov 12, 2014
221
Cayuga County NY
Hey ya'll, if anybody is having a bad day, maybe feeling like they've mad a stupid mistake, let me see if I can brighten things up for you by sharing one I made last night involving the blower motor on my forced air propane furnace. Let me give a brief background - I have a 1 story ranch, about 1,500sqft, along with 600sqft of finished basement connected to the house by a fairly large, open stairway leading to a fairly open center of the home. My 20 year old Winrich Dynasty pellet stove provides heat to the whole house pretty well from the finished section of the basement, I use a few fans to move things to the side rooms. Last week I ordered a Timber Ridge PAH from AMFM to replace the Dynasty - I wanted something I could run on a thermostat, auto ignition, big hopper, etc. Part of this upgrade was also to use my forced air propane furnace to help move the air around the house. I've been constructing a cold air return in the wall right below the ceiling in the finished room where the pellet stove is - the idea here is to use a thermostat set on cool mode to run the furnace blower to push the warm air around the house whenever it hits a warm enough temperature in the finished section of the basement where the stove is. I will run the pellet stove on a programmable thermostat upstairs to regulate temperatures as I like - pellet stove kicks up and then the furnace starts moving air once it's warm enough so it doesn't feel cold at the ducts. It'll take a little tuning but I think it'll work nice.

So, part of this plan obviously requires wiring in a second thermostat. While I was connecting this up at the furnace I decided I would change the blower speed so it would run at it's slowest speed, just gently moving warm air upstairs. I read and reread my furnace manual and some how got in my head that there were three feeds from the control board to the furnace motor - once for heat speed, one for cool speed, and one for blower speed. Since I'm installing central A/C in the spring I thought perfect, I can use the third speed, blower, for my low speed heat distribution without having to give up my high speed setting for cool. I went ahead and changed the jumper labeled blower, the white wire (I'm sure a few of your know where this is going now) over to the red. Little did I realize I had just unhooked the common/neutral wire and placed the low speed windings in it's place. I energized the system and called for fan only at the thermostat. The lights dimmed, the motor groaned, and the smoke flowed! I quickly got the power off, but the damage was done. I had essentially shorted the high speed windings in the motor to the low speed windings in the motor. I quickly realized my mistake, but the motor is toast. It will actually run, but just barely, no matter which circuit you feed. The control board seems ok, I will know for sure tonight once I install a replacement motor - boy those are expensive. So, if you've had an a bad whoops today, just know you're not the only person who made a stupid goof that cost them a bunch of time and money.

And the worst part is I'll have to wait another night or two before I get to play with my new PAH! I guess I should just be happy the old Dynasty works so good and I don't have to depend on the propane.
 
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!!! oy vey! <> bummer. ive had "whoopsies' in my time as well, at least you can look at it with some gallows humor i suppose.

we all make mistakes , as long as nobody gets hurt its all in education i guess.
 
How bout setting the fan mode to ON. You could even got a american standard gold hd thermostat and programmed the fan to on a temperature programm like heat does.. Sorry to hear about the motor
 
How bout setting the fan mode to ON. You could even got a american standard gold hd thermostat and programmed the fan to on a temperature programm like heat does.. Sorry to hear about the motor

Yea, I'll be all set with a new motor, I'll just use the low speed on the cool circuit for the winter, and then when I switch over my cold air returns to the one upstairs I'll just flip the jumpers. It's not that big of a deal, just thought I'd found a way around it. I still can't believe that rookie mistake - I've done plenty of home electrical and wiring projects. Hopefully I can get the furnace back online tonight and finish my ducting project. Then tomorrow I can get the pellet stoves switched out and be wrapped up with this little project. Once it's up and running I'll get some pictures and post a new thread - it should be a pretty cool setup.
 
New motor is in and works fine with both thermostats. Now I can get back to the return and maybe tomorrow be ready to install the new stove. Gonna keep it stupid free from here on out, I hope
 
I have a honeywell thermostat that has a circulate option. It comes on randomly every 10 to 15 mins and runs for about 5 minutes
 
Ouch! We have all been there. I decided that I wanted to put half and outlet on a switch one day, popped a switch box in, ran a three wire, etc. Flipped the breaker only to realize that I some how forgot to clip the tab between the top/ bottom outlet. :p
 
Reminds me of the time I stuck my screwdriver in the wrong place on a main circuit breaker panel in the shop. In a flash, all I had left was the handle.... Thaat 440/3 is a cooker.

Temporarily blind from tha arc flash too.....
 
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Reminds me of the time I stuck my screwdriver in the wrong place on a main circuit breaker panel in the shop. In a flash, all I had left was the handle.... Thaat 440/3 is a cooker.

Temporarily blind from tha arc flash too.....

That one seems to be a step up from a whoops that toasted a furnace motor....

acammer, that would be the reason why I desperately try to avoid wiring projects. If I have to, I usually draw the diagram or take photos. Never been up to modifying as that would guarantee a screw up;)
 
Well, on recirculating hone air, I have a LUX-CAG series T'stat that does it on 'Clean-Air' cycle automatically, 5 minutes, every 15 minutes. LUX quit making them, don't know why about 5 years ago. Great for keeping whole house temps even with the stove supplying the heat.....Plug-n-Play, no wiring, no smoke.....:)
 
Curious. Those of you using air handlers etc to recirc warm air, isn't the heat loss thru the ductwork, even if insulated, enough to make this counter-productive? Also, there is a cost associated with running the blower both in energy and wear-and-tear. I've tried this and found it doesn't do much for me.
 
Curious. Those of you using air handlers etc to recirc warm air, isn't the heat loss thru the ductwork, even if insulated, enough to make this counter-productive? Also, there is a cost associated with running the blower both in energy and wear-and-tear. I've tried this and found it doesn't do much for me.


It work okay in my place but there is no duct work in an un-insulated space. If you have the duct work running thorough an un heated crawl space I have to Imagine you would loose tons of heat.
 
Yea, he majority of my duct work is highly insulated, with a few parts in the basement that are more open. The advantage I have, I think, will be the location of my cold air return, right at the ceiling of the finished basement where all the heat collects from the pellet stove. That area sees 90*F+ of heat - so if I can push some of that around to the upstairs it should also have the effect of pushing some cold air back down the stairs for warming. I guess we'll see how it work in another day or two. Look for a new thread with some pictures at that point.
 
We have a pellet stove in the basement and a central HVAC air handler for the basement and 1st floors. Because I wanted to be able to move the heat around at a low speed I replaced the motor on my air handler with a "Concept 3" motor that runs at different speeds depending upon HVAC mode choice. Evergreen is another maker of retrofit motors for air handlers. These motors are more efficient and quieter than the standard AC motors they replace.
There's a good discussion here on the subject if interested: http://www.greenbuildingadvisor.com/community/forum/mechanicals/20709/swapping-ecm-psc-fan-motor
 
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