Fulton Alliance (FT-HC) Horizontal Coil Thermal Fluid (hot oil) Heater - Manual (Page 46)

© The Fulton Companies 2012
OPERATION
FTHC-IOM-2012-1001
SECTION 3
3-10
!
WARNING
All information in this manual is for
reference and guidance purposes,
and does not substitute for required
professional training, conduct,
and strict adherence to applicable
jurisdictional/professional codes and
regulations.
Should overheating occur or the gas
supply fails to shut off , manually shut
off the gas supply external to the
equipment .
 SEQUENCE OF OPERATION FOR ON/OFF BURNER
The sequence of operation for the on/off burner is as follows:
1. Beginning with power on, limit switch closed, fuel valves closed, and
temperature controller calling for heat, the fl ame programmer starts the
cycle and the blower motor starts prepurge.
2. The air proving switch must be closed now. Air dampers remain in
maximum position.
3. (Gas Pilot) Provided all safety interlocks are proven, ignition and pilot are
energized and a timed trial for pilot ignition begins. After the pilot fl ame is
proven, the main fuel valve is energized. Ignition is turned off when fl ame
is registered and the main gas valves open.
4. (Spark Ignition) Provided all safety interlocks are proven, the spark is on
and oil valves are opened. When the fl ame is proven, the spark is shut off .
5. When the fl uid temperature reaches the off setting (typically the setpoint
plus 2 to 5 degrees) of the operating temperature controller, all fuel valves
are closed.
The burner motor stops and the entire system is ready for restart on demand.
 MODULATING BURNER
The function of the fl ame programmer must be greatly extended in a modulated
system. Along with limit controls, operating controls and interlock devices, the
programmer automatically controls the operation of the burner, blower motor,
ignition, main fuel valves and modulating motor (or servo motors).
The sequence of operation is as follows:
1. Beginning with power on, limit switch closed, fuel valves closed, and
modulating limit controller closed and calling for heat, the fl ame
programmer begins its cycle and the blower motor starts prepurge.
The modulating circuit closes, driving the air dampers to maximum for
prepurge.
2. The air fl ow proving switch must be closed now. After timed prepurge,
the modulating motor (servo motor) drives the air damper to its low fi re
position. All start interlocks must be proven or the fl ame programmer will
lockout.
3. (Units with Gas Pilot) Ignition and pilot are energized and a timed trial for
pilot ignition begins. After the pilot fl ame is proven, ignition turns off and
the main fuel valve is energized. Pilot fuel is turned off and the modulating
motor (servo motor) is released to automatic.
4. (Units with Spark Ignition) The spark and oil valves are energized and a
timed trial for ignition begins. With the fl ame proven, the control advances
through its main light off sequence, and the ignition shuts off . At this time,
with the fl ame proven, the modulating motor (servo motor) is released to
automatic.