GF - B 1
Induced Draft Motors
Variable Speed Three Phase Induced Draft Motors .................................................................................................. 2
Introduction ........................................................................................................................................... 2
Electrical circuit .................................................................................................................................... 2
Sequence of operations ........................................................................................................................ 2
First stage learning routine ................................................................................................................... 2
Vent pressure switch must be open prior to motor starting .................................................................... 3
Learning routine .................................................................................................................................... 3
Second stage learning routine............................................................................................................... 3
Induced draft blower operation after learning routine .............................................................................. 4
Troubleshooting .................................................................................................................................... 4
Communicating Gas Furnaces
Section B