THIS IS OBSOLETE AND NOT LONGER MANUFACTURED FOR CARRIER / BRYANT FEW LEFT LOOKING FOR A AFTER MARKET REPLACEMENT
Carrier, Bryant, Day & Night, Payne Furnaces use this 3-wire Pilot
740A Electronic Ignition Switch with built-in Safety
Style/Model: 740A
Orifice Size : .017
Differential expansion pilot equipped w/ a 3 lead SPDT switch for use w/ a hot suface Ignitor or spark Ignition
(YELLOW, WHITE, GREEN WIRES WITH MOLEX PLUG ADAPTER)
Replaces Pilot Burner Part Numbers
535740A 535-740A LH680005 1830-620 535-740 535-740A LH680005 P671-1406 CARL38999 CAR1830620 740A 1830-620 535740A
The pilot does have a relay, it is heat activated (warp bar), it is in the bottom of the three-wire pilot module.
The sparker is just a sparker the heat activated relay is how it "senses" flame. Yellow is the common number 2/3 on gas valve.
Green (number 5 on gas valve) open the pilot valve when the pilot module is cold.
White opens the (number 1 on the gas valve) main valve when the module heats up. The warp bar is what makes the switch.
|