Defrost conversion from mechanical timer to electronic

[skidplatebob]

I have a Carrier Weathermaster HVAC unit that is about 20 to 30 years old. The outside coil section continually freezes up and the timer is bad. What defrost board can i use and how to convert over. I am a mechanical engineer with alot of electrical experience also but not familiar with this equipment. I just don't know where to start. Future plans are to replace with more efficient unit but because of money issues it needs to last a few more years. Any and all help would greatly be appreciated. Thank You.

[nomadpeo]

i'm sure there will need to be some degree of modification. if this is a heat pump, you can probably use a universal control. you will just need to study the specifics of that unit and make sure signals are routed the same way on the new one. i would see if carrier has a replacement. it will not be the same as the original, of course, but some instructions will come with it if it is meant to replace yours. also, make sure the timer is the problem. there are other components involved.