BTR TANK TYPE HEATERS

SERVICE HANDBOOK

A.O. Smith Water Products Service Handbook
Irving, Texas ©2000 Training Department

18

BTR ELECTRICAL SEQUENCE OF OPERATION
MotorOpens
Damper
Powerto Damper
#2 Interrupted
Series 110 and 111
Effikal
Series110 and 111
Effikal
IIDM odule
(24V) Receives Voltage
Module(PV)Teminal
Sends 24V to PilotCoil
Module(Spark)Sends
10,000V Spark toPilot
SparkStops
Damper Motor Energized
and Damp er Closed
Powerto Damper
Relay(4) Interupted
Themostat Opens
Main Burner Heats Tan k
Module(MV)
Terminal Sends 24V
To Main Gas C oil
90 Second Trial /
5 Minute Delay Between
Trials - C o n tin u ou sly
PilotIgn itesand P rovesF lame
Cam On Damper Blade
Closes Proving End Switch
Damper SpringOpens
Damper Blade
Motor Re lay Interrupts
Power to Motor
Thermostat Closed
HighLimit Closed
Tank Temp erature
Motor Closes
Damper
High Limit(ECO)
Closed
Tank Temp erature
Satisfied
24V Transformer
On / OFFSwitch "ON"
120 Vac to Junction Box