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Doubts about schematic for fan motor control on 230VAC

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Please straighten my worn-out brain. Will need a little of your patience.
A furnace blower schematic seems mind twister, and I did redraw it simpler trying to understand the circuitry. Still do not get it.

----> http://www.alpinehomeair.com/related/ARPF Spec1.PDF

The blower motor 'EM' schematic on page 6 with the second option (2 heating elements shown above) works on 230VAC into its purple and black wires. Its slow speed red wire terminal can be ignored, is at M1 which is only a parking place so its terminal is not touching anything else.

What is the function of the purple wire from normally closed EBTDR relay contact trough pin 3 of molex connector into M1 of relay R ?


Well-Known Member
Most Helpful Member
The way I see it the pin 3 of the Molex dead ends there and similar to 4&5 are there for an option, if so at present the purple to pin 3 does nothing.
An in circuit test could show more by continuity and voltage testing.
It could also be a permanent in- run option when heating used.
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