Author Topic: Blower motor is... blown  (Read 3527 times)

Offline Alcaeus

  • VIP Member
  • Member Since: Oct 2008
  • Posts: 5
Blower motor is... blown
« on: October 29, 2008, 09:18:10 PM »
I recently had a guy come out to look at my HVAC unit. He said that my blower motor might be going bad and my contactor and my condenser fan motor were caput then generously offered to fix it for me for 1500 dollars  :2funny:

I found a granger and purchased both parts for $91.00 and installed them myself.

I slip in the breaker and the whole thing come on purring like a kitten. At this point I go into my house and feel cool air coming out of the vents.

Here comes the problem.

Suddenly I hear a muffled bang and smell an electrical fire. I go to my AC and the thing is still running but the blower motor is now not moving.

I purchase a replacement thinking that its the motor just going out and put in in for $70.00. I slip in the breaker and the whole thing comes on. Im sitting in front of the open panel that the blower motor is in and i hear a muffled explosion and see fire inside the blower motor!   >:(

I'm assuming that there is something wrong with the way I wired it. I'm almost positive that I put the wires on exactly how they were on the original parts.

I did get a new matching capacitor and I made sure that all of the specifications on the motor were the same.

Is it possible that the contactor has something to do with it? or that two different speeds are trying to go on at the same time and shorting the motor?

I tested the voltage on the board for the cold hot and com lines. both Hot and Com read 121 volts but the cold was showing 4v max. Is my board bad?

Also I plugged in a new motor with only cold wired to a speed = nothing happens.

I wired up hot to a speed and my motor turned on but was making bad noises and started to smell. The motor was being burnt out! I pulled the breaker before it could go to far.

What does that all add up to for you guys?

Offline JWWebster

  • Technician
  • Member Since: Jan 2008
  • Posts: 8780
  • Country: us
  • SublimeMasterJW
    • Buy me a beer through paypal
    • JW's Sublime Appliance Advice
Re: Blower motor is... blown
« Reply #1 on: October 29, 2008, 09:58:20 PM »
Do you have gas or electric heat? If you have electric heat then maybe you are installing a 120 volt motor when you need a 240 volt motor?
« Last Edit: October 29, 2008, 10:07:58 PM by JWWebster »
May the hinges of our friendship
        never grow rusty.

About the icons: The beer is tip link, if a tech saves ya some money buy em a 6 pack. The small green square=personal message. The green dot is a link to my web page on appliance repair and other general BS I love to post. The letter sends me email.
I love fan letters! LOL

Offline Alcaeus

  • VIP Member
  • Member Since: Oct 2008
  • Posts: 5
Re: Blower motor is... blown
« Reply #2 on: October 29, 2008, 10:19:42 PM »
its gas.  I made sure that the specs on the motors were the same.

Old Blower-
Volt 208-230
R.P.M. 1075/4SPD
HZ 60
AMP 4.4
PH1
HP 1/2

New Blower-
Volt 208-230
R.P.M. 1075/3SPD
HZ 60
Amps 3.8-3.7
HP 1/2

They seem to be comparable to me and I wasn't using all the speeds on the old motor so the speed difference wasn't an issue.

I used the original wiring and connected it to the blower motor with wire nuts. Its a unit on the roof and its all in the one unit. Heating and cooling. Its a Heil unit.

Offline JWWebster

  • Technician
  • Member Since: Jan 2008
  • Posts: 8780
  • Country: us
  • SublimeMasterJW
    • Buy me a beer through paypal
    • JW's Sublime Appliance Advice
Re: Blower motor is... blown
« Reply #3 on: October 29, 2008, 10:29:58 PM »
I have never heard of 220 volt blower motors for gas heat. Sorry New stuff to me.
« Last Edit: October 29, 2008, 10:34:53 PM by JWWebster »
May the hinges of our friendship
        never grow rusty.

About the icons: The beer is tip link, if a tech saves ya some money buy em a 6 pack. The small green square=personal message. The green dot is a link to my web page on appliance repair and other general BS I love to post. The letter sends me email.
I love fan letters! LOL

Offline Alcaeus

  • VIP Member
  • Member Since: Oct 2008
  • Posts: 5
Re: Blower motor is... blown
« Reply #4 on: October 29, 2008, 10:37:44 PM »
Why would I have no volts on the cold wire on my board?

Why does it burn up when I only connect the heat wire?

I assume its gas because it has a gas looking line going to it and it has burners.

why is there a line for heat if i don't use it?

the old motor had 4 speeds and two were hooked up to the hot and cold lines.

Thanks for your responses!

Offline Alcaeus

  • VIP Member
  • Member Since: Oct 2008
  • Posts: 5
Re: Blower motor is... blown
« Reply #5 on: October 29, 2008, 10:40:06 PM »
The new motor should use only black HI and common (white or purple) All other wires need to be individually taped off away from each other and not touching anything. 2 browns should be connected to capacitor and it should be taped off too.You have electric heat. That only requires one speed for both ac and heat. All other speeds are not needed.

I was replying to this when I typed the above. 

Offline JWWebster

  • Technician
  • Member Since: Jan 2008
  • Posts: 8780
  • Country: us
  • SublimeMasterJW
    • Buy me a beer through paypal
    • JW's Sublime Appliance Advice
Re: Blower motor is... blown
« Reply #6 on: October 29, 2008, 11:52:56 PM »
That would have been for electric heat. You say you have gas heat.
May the hinges of our friendship
        never grow rusty.

About the icons: The beer is tip link, if a tech saves ya some money buy em a 6 pack. The small green square=personal message. The green dot is a link to my web page on appliance repair and other general BS I love to post. The letter sends me email.
I love fan letters! LOL

Offline Alcaeus

  • VIP Member
  • Member Since: Oct 2008
  • Posts: 5
Re: Blower motor is... blown
« Reply #7 on: November 01, 2008, 11:13:39 PM »
The contactor was the problem.  I think that one of the poles was bad and I wasn't getting enough voltage to the motor.  The motor amped itself up and burned out because it was trying too hard.

I replaced the contactor and the problem went away. 

Thank you all for the help. :)

 

blower motor conversion

Started by hvacapprenticein

Replies: 5
Views: 3652
Last post July 20, 2008, 02:46:48 PM
by JWWebster
Compressor Runs-Blower motor doesn't

Started by Blockhead

Replies: 7
Views: 3622
Last post July 31, 2009, 10:45:02 PM
by Blockhead
wire new blower motor

Started by julie cortez

Replies: 0
Views: 223
Last post December 09, 2013, 06:47:41 PM
by julie cortez
AC Blower Wiring Questions

Started by billnc

Replies: 6
Views: 12473
Last post June 18, 2008, 11:43:13 PM
by JWWebster
Treating a Motor That ‘Nuisance Trips’

Started by Icehouse

Replies: 0
Views: 1886
Last post January 24, 2009, 07:38:18 PM
by Icehouse
Lennox G26 Combustion Air Blower Part Number?

Started by AJ

Replies: 11
Views: 12951
Last post March 09, 2010, 01:18:59 PM
by whodatis67