8
60706-236/J
INSTALLING LP/NG FUEL LINE
The information in this manual is offered to assist you in
providing the proper vapor fuel supply for your engine. This
information is only provided to advise you of the engine’s
requirements and the decisions you must make. In no case
should this information be interpreted to conflict with any
local, state, or national codes. If in doubt, always follow local
codes.
DANGER: FIRE/PERSONAL INJURY
All fuel lines must be installed by a qualified fuel
supplier.
DANGER: FIRE/PERSONAL INJURY
The LP/NG fuel supply line must always be shut off
when the engine is not running. Failure to do so may
allow fuel to leak at the unit.
DANGER: PERSONAL INJURY
Units that are intended to be run unattended MUST
have an electric fuel solenoid installed. This solenoid
MUST be wired to AUTOMATICALLY turn off the fuel
whenever the engine stops.
The fuel source should be as close as possible to the
outdoor operating location. This will reduce the installation
cost of fuel runs. Connect the fuel supply line to the inlet
of the fuel demand regulator on the unit using a locally
approved flexible fuel line (see table for recommended line
size). The pressure supplied to the demand regulator must
be 4 to 6 ounces or 7 to 11 inches w.c. (water column).
Any lower pressure and the unit will starve for fuel under
load. Any higher and the unit will ‘flood’ when attempting
to start. The primary regulator at the fuel supply must be
capable of delivering the proper volume of fuel at this
pressure.
Have your local fuel supplier install a protected fuel
connection at the outside operating location. They should
also install a lockable fuel shut off valve at the connection
point. An approved flexible fuel line must be installed
between the engine generator set and the supply line. The
fuel line used to connect the supply line to the demand
regulator must be a locally approved flexible fuel line.
Products used will vary in different regions depending on
availability and local codes. Consult with your local fuel
supplier to ensure complete compliance with ALL codes.
1. Remove the plastic cover plug from the demand
regulator.
2. Connect the flex fuel line to the demand regulator or
the optional solenoid.
Size of pipe required for generators operating on NG/LP
gas.
Length of fuel line* Fuel line size
Less than 25 feet
3/4 in black pipe
25-100
Feet
1
in
black
pipe
Over
100
feet Not
recommended**
*Allow an additional 3 feet for each standard elbow. Do not
use ‘street ells’ (restrictive).
**Consult factory for fuel run over 100 feet.
DANGER: FIRE/PERSONAL INJURY
Be careful when sealing gas joints. Excessive sealing
compound can be drawn into the solenoid, regulator,
or carburetor causing an engine malfunction or dan-
gerous fuel leak.
DANGER: PERSONAL INJURY
Do NOT use galvanized pipe in the fuel line runs. The
galvanized coating will become eroded and flake off,
causing possible obstruction or damage to the reg-
ulator or fuel valve. The obstruction could cause an
inoperative engine or an explosive fuel leak.
NATURAL GAS
Correct fuel pressure cannot be stressed enough. The most
common cause for inoperative systems is an inadequate
or incorrect fuel pressure. Power and performance of the
engine is in direct relation to the correctness of the fuel
system. The following diagram is of a typical NG installation.
Reference numbers 2 and 3 in the previous diagram are
system parts supplied by the customer. Reference number 4
is the engine-generator set. The following table is of the fuel
pressure reading at each reference in the system.
Natural Gas Fuel Pressure Table
1
2
3
4
Unit Off
Tank PSI
10-15 lbs
7-11 in
4-6 oz
7-11 in
4-6 oz
Starting
Tank PSI
10-15 lbs
7-11 in
4-6 oz
7-11 in
4-6 oz
No Load
Tank PSI
10-15 lbs
7-11 in
4-6 oz
7-11 in
4-6 oz
Full Load
Tank PSI
10-15 lbs
7-11 in
4-6 oz
7-11 in
4-6 oz
LP VAPOR
LP TANK SIZING
The tank sizes shown below are the smallest recommended
tank sizes based on the outside temperature. Once above
this minimum acceptable size, the size of LP tank used will
generally depend on how long you want the unit to run
without refilling. Keep in mind the colder it gets, the slower
LP will vaporize. This is the reason for the larger tanks at low
temperatures. Minimizing sizing is NOT based on running
time.
Temp (F)
60°
30°
0°
-20°
150 gal
250 gal
500 gal
1000 gal
13240-11
8
60706-236
Natural Gas
2
3
4
UNIT OFF
LINE PSI 7-11 in
7-11 in
4-6 oz
4-6 oz
STARTING
LINE PSI 7-11 in
7-11 in
4-6 oz
4-6 oz
NO LOAD
LINE PSI 7-11 in
7-11 in
4-6 oz
4-6 oz
FULL LOAD
LINE PSI 7-11 in
7-11 in
4-6 oz
4-6 oz
Remember that whichever fuel delivery system or
type of vapor fuel used, the fuel pressure at the
demand regulator installed on the engine generator
must be between 4 and 6 oz. (7-11 inches of water
column). Any lower pressure and the unit will starve
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when attempting to start.
LP TANK SIZING
The tank sizes shown below are the smallest recom-
mended tank sizes based on the outside temperature.
Once above this minimum acceptable size, the size of
L.P. tank used will generally depend on how long you
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the colder it gets the slower L.P. will vaporize. This
is the reason for the larger tanks at low temperature.
Minimum sizing is not based on running time.
Temp f. 60 deg
30 deg
0 deg
-20 deg
150 gal
250 gal
500 gal 1000 gal
CHANGING FUEL TYPES
These engine generator sets are designed to run
on three different fuels; gasoline, natural gas or LP
vapor. They may be easily changed from one fuel to
another.
FROM GASOLINE TO LP/NG
1. With the engine running turn off the gasoline
fuel valve.
2. Run the engine until it runs out of fuel.
3. Remove the plastic insert from the demand
regulator.
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&RQQHFWWKH/31*YDSRUIXHOOLQHWRWKHÀH[
-
ible fuel line. You can’t connect the black iron
pipe dir
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on the top of the demand regulator. One is for
LP and one is for Natural Gas. Make sure the
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picture below.
7. Turn on the vapor fuel.
8. Start the engine.
9 . Apply the load to the generator.
FROM LP/NG TO GASOLINE
1. With the engine running turn off the LP/NG
fuel supply.
2. Run the engine until it runs out of fuel.
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regulator.
4. Reinstall the plastic insert in the regulator.
5. Check to be sure the gasoline fuel valve is off.
6. Fill the gasoline fuel tank.
7. Turn on the gasoline fuel valve.
8. Start the engine.
If the optional FUEL SOLENOID kit has been in
stalled on the unit all vapor fuel connection will be
made at the 12 volt gas valve.
