Can't figure this 3 wire system out or find anything in postal about it

A C Furnace To Condenser Wiring Diagram

Amp for electric furnace wiring diagram Ge gas furnace wiring

Furnace blower Furnace ge Thermostat wiring wire heat color diagram pump air nest guide common goodman colors honeywell code labels heater aruf handler wires

Amp For Electric Furnace Wiring Diagram - Suspension Diagram

Can't figure this 3 wire system out or find anything in postal about it
Amp For Electric Furnace Wiring Diagram - Suspension Diagram
Amp For Electric Furnace Wiring Diagram - Suspension Diagram

Can't figure this 3 wire system out or find anything in postal about it
Can't figure this 3 wire system out or find anything in postal about it

Ge Gas Furnace Wiring | Wiring Diagram - Gas Furnace Wiring Diagram
Ge Gas Furnace Wiring | Wiring Diagram - Gas Furnace Wiring Diagram