Fulton Hopkins (HPN) Horizontal Coil Thermal Fluid (hot oil) Heater - Manual (Page 42)

© Fulton Companies 2014
OPERATION
HPN-IOM-2014-0416
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 .
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.
5. When the modulating motor (servo motor) is released to automatic,
it receives its signal from the modulating temperature controller. The
modulating motor (servo motor) then drives the modulating fuel valve and
air damper in proportion to the heat demand.
6. During the initial call for heat, the modulating fuel valve and air damper will
drive to their full-fi re position. As the temperature set point is approached,
the modulating motor (servo motor) will continue to reduce the input until
low-fi re position is reached. Input automatically increases and decreases
according to load demand.
7. When the fl uid temperature reaches the set point of the temperature
controller or of the optional operating limit controller, all fuel valves will
close and the fl ame programmer will advance to the post purge cycle.
When the postpurge cycle begins, the modulating motor will be in the low
fi re position. At the end of postpurge, the burner motor stops and the entire
system is ready for restart on demand.
 OIL FIRED BURNER
The following refers to the design and operation of the on/off burner utilizing
fuel oil which requires no preheating. This burner is of high pressure, mechanical
atomization design.
The sequence of operation is as follows:
1. An oil pump is used to obtain necessary atomizing pressure before the fuel
oil reaches the nozzle. The fuel oil is divided into fi ne particles in the nozzle
and imparted with a rotating motion before escaping from the nozzle as a
cone of fi nely atomized oil.
2. Combustion air is supplied by a centrifugal fan. A damper provides
throttling of the inlet opening. The air from the fan reaches the burner
head after going through a turbulator, accomplishing correct distribution
and mixture of air and atomized fuel oil.
3. An electric spark between two electrodes provides ignition of the
atomized mixture, except where code requires a gas pilot. This spark is
produced by a high voltage transformer.
4. The fl ame programmer circuit controls normal operation of the burner.
The sequence includes purging of the combustion area for a set period,
ignition and opening of magnetic valves on the oil circuit; post-purge of
combustion area and return to re-start position.