16
Maintenance
Fuel Control System
The HS-3000 utilizes a fuel solenoid valve located on
the fuel pump to control the flow of fuel to the combus-
tion chamber. This solenoid, which is normally closed,
is activated by a flow switch when water is flowing
through it. When an operator releases the trigger on the
spray gun, the flow of water through the flow switch
stops, turning off the current to the fuel solenoid. The
solenoid then closes, shutting off the supply of fuel to
the combustion chamber. Controlling the flow of fuel in
this way gives an instantaneous burn or no burn situa-
tion, thereby eliminating high and low water tempera-
tures, and combustion smoke normally associated with
machines incorporating a spray gun. Periodic inspec-
tion is recommended to insure that the fuel solenoid
valve functions properly. This can be done by
operating the machine and checking to see that when
the trigger on the spray gun is in the off position, the
burner is not firing.
Fuel Pressure Adjustment
To adjust fuel pressure, first install a pressure gage into
the port just after the pump fuel exit. Turn the adjusting
screw (located at the regulator port) clockwise to
increase, and counterclockwise to decrease. Do not
exceed 200 psi or lower the pressure below 130 PSI,
when checked at the post-pump pressure port.
The fuel pressure may need to be adjusted due to
altitude. For every 500 ft altitude above sea level, the
boiling point of water goes down 1 °F. At high altitude
environments, this boiling point change may require the
heat input to be lowered so the water input does not
turn to steam earlier than at the factory settings and
activate the pressure sensors and pressure relief
equipment when the unit is operated and much higher
altitudes from factory settings or local dealer site
settings. Check with your dealer before making local
site fuel pressure adjustments.
Also, as ambient temperature changes seasonally, the
fuel temperature in the feed tank and air temperature
inlet can impact fuel flow. In more extreme tempera-
tures, this local-site adjustment may also require
different fuel nozzles for fuel inlet temperatures that are
at seasonal extremes (higher or lower) in locations
where the temperature changes are beyond moderate
temperatures of between 40°F and 90°F. Colder
temperatures will make for a thicker flow and less fine a
fuel spray while hotter temperatures will make for a
thinner flow a more fine spray with the same nozzle.
Consider alternate nozzle configurations from the
baseline factory-supplied nozzle for operating in such
temperature extremes if performance is not meeting
needs with air band and fuel pressure settings alone.
NOTE: When changing fuel pump, a by-pass plug
must be installed in return line port or fuel pump will
not prime.
Air Adjustment
The oil burner on this machine is preset for operation at
altitudes near 500 feet. If operated at higher altitudes, it
may be necessary to adjust the air band for a #1 or #2
smoke spot on the Bacharach scale.
To adjust, Loosen locking screw found on the air band.
Start machine and turn burner ON and close air band
until black smoke appears from burner exhaust vent.
Note air band position. Next, slowly open the air band
until white smoke just starts to appear and note air
band position, again. Rotate the air band halfway
between to the previously noted positions. Tighten
locking screws. Typical distance from the 'black smoke'
position is roughly 3/8"-1/2" more open from the point of
visible black smoke, but may vary based upon local
operating conditions.
•
For higher altitudes, the air band opening may
need to be increased; for lower altitude, the air
band may need to be decreased.
•
For higher humidity, the air band opening may
need to be increased; for lower relative
humidity, the air band may need to be
decreased.
•
For higher ambient temperatures the air band
opening may need to be increased; for lower
ambient temperatures, the air band opening
may need to be decreased.
Adjust the burner to your operating location's environ-
ment as-needed for best smoke spot and performance
compliant with local, state, and federal regulations.
Example: a unit preset at a factory at 1700 feet altitude
with an air band of 1.1" and fuel pressure of 190 PSI
with Ambient temperature of 72 °F and a relative
humidity of 84% using #2 Diesel fuel oil. The unit is
shipped to a location at 5300 feet altitude with ambient
air temperature of 59 °F and a relative humidity of 25%.
The air band required adjustment to 1.8" opening and
fuel pressure lowered to 150 PSI for a high altitude
adjustment for both heat input adjustments and
combustion air intake with the same fuel type.
.
Landa HS Operator’s Manual 8.913-943.0 - P
