Winco PSS20000 - Manual (Page 8)

PAGE 6
LP LIQUID WITHDRAWAL
The following is a block diagram of a typical L/P Liquid
Withdrawal fuel system for the PSS20000.
Tank Fuel Solenoid Converter Engine
1 2 3 4
Reference number 1 is the fuel tank. No regulator is
required but the tank must have a liquid withdrawal
drop tube installed in it and a liquid valve on the tank.
Reference number 2 through 4 are installed on the engine
generator set.
Liquid fuel is delivered from the tank directly to the fuel
solenoid on the generator at full tank pressure. This
system requires no pressure regulator be installed
any where in the system. The converter mounted on
the engine generator set will take the liquid fuel at tank
pressure and convert it to vapor at the proper delivery
rate.
LP/NG FUEL ADJUSTMENTS
**** CAUTION ****
Do not make any fuel adjustments or governor adjust-
ments until all pressure readings are in compliance
with specification. See fuel pressure charts (tables 1,
2, and 3).
NATURAL GAS (NG)
Due to variations in NG fuel characteristics and BTU
levels throughout the country, it may be necessary to
readjust the fuel mixture once the engine has been
installed and serviced.
**** CAUTION ****
Never make a fuel mixture adjustment on a unit when it is
stopped or running no load. A mixture adjustment is
only effective when the engine is operating under load.
ADJUSTMENT PROCEDURE
1. Insure the unit is operating with an 80 to 100% load or
at the highest anticipated load.
2. Attach a frequency meter to monitor Hz.
Note: The fuel mixture adjustment on the PSS8000 &
PSS12000 is the brass load block located on top of the
demand regulator. This load block is a multi-turn
needle valve. On the PSS20000 it is located on the
carburetor just behind the fuel inlet hose. This mixture
adjustment is a partial turn, lean to rich, load block.
3. Begin making a mixture adjustment, observing the Hz
meter. If the meter begins to drop you have the mixture
set too lean or to rich . Adjust the valve in the opposite
direction. Adjustments should be made very slowly.
Adjust back and forth until the highest Hz is achieved.
Do not turn the valve richer after the Hz quits rising,
this would cause the engine to run rich. If the Hz is out
of upper or lower limits, a governor adjustment will be
necessary.
4. On the PSS8000 & PSS12000 see your engine
manual for governor adjustment procedures. The
PSS20000 is equipped with an electronic governor
which requires no adjustment.
**** CAUTION ****
Under full load do not adjust the Hz above 60. If a higher
Hz reading is used, as the load is decreased the Hz
will go out of upper limits (61 to 62 Hz).
PROPANE (LP)
A generator set factory tested on LP will normally require
no adjustment. If for some unforeseen reason the
machine should require adjustment, follow the NG
procedure.
FUEL TYPE CONVERSION
If it should be necessary to change the type of fuel used
after a unit is received, the following procedures are
provided.
PSS8000
These units require no changes to the regulator. After
plumbing in the fuel lines the only thing necessary is to
reset your mixture as detailed in the adjustment
section above.
PSS12000 & PSS20000
NATURAL GAS TO PROPANE
1. Turn off fuel supply.
2. Remove the fuel line from the carburetor at the
demand regulator.
3. Remove the cap on the upright column of the regula-
tor. This will expose the pressure spring adjusting
screw. Back off the spring adjusting screw so there is
just enough room to replace the cover. Replace the
cover
4. Invert the regulator so it is positioned with the column
pointing down.
5. Reconnect the fuel line at the regulator.
6. Remove the 1/8 NPT plug (the one closest to fuel
solenoid) located on what is now the top of the
regulator. Connect a fuel pressure meter or a manom-
eter where the plug has been removed. Move the
generator control switch to the run position. As the unit
starts to crank the fuel solenoid will open and you
should get a pressure reading of between 4 to 6
ounces (7 to 11 inches of water column).