RUDD furnace fan control

[jrc2905]

I post this here because for some reason I cannot get into the pro forum.


Hi, I am working on a RUUD oil fired hot air furnace. The unit is going off on limit due to failure of the fan timer not turning on. The fan timer suffered heat distortion and failed, the result of the blower motor not turning on. The brand on the timer is A1 components #47-22896-01. It has three 24volt connections. For the fan motor it has three 120volt terminals, COM, N.O. and N.C. I have not seen this timer before. I have a new one but no wiring diagram came with it nor is the any on the furnace, the furnace wiring is suspect. Can anyone tell me how the three 24 volt connections are used? The fan motor will run if I use the common and N.C. and all other components test out on this unit. I was thinking about using a sequencer for the fan timer instead. Any information is appreciated.

[mubarak]

yes in my opinion i think that the three 24volt wiring connection is that one is L1 and L2 and the other one is Neutral which is in the middle that you don't even really need it. if that is the answer let me know

[marylandtech]

No on this control the 3 terminals are 24 volts. One is R one is G and one is C. (xfmr hot, fan from fan center, common from xfmr) Now the terminals in the middle you only use the common and the NO. These contacts break the Blower fan speed. Those relays are junk, I dont know why they use them..

[jrc2905]

Thanks, the supply house faxed me the wiring diagram. the other fan timer failed because the 24 volt wiring was wrong. It is a pain but I like it when I find something differant, makes me learn something new.