Gillette Generators SPP-180 User Manual
Page 13

PAGE 13
EXAMPLE 2: A model SPP-180, 16 KW generator is to 
be installed 50 feet from gas meter. In reading the 
charts, Fig. 1 shows this model to require 280 cubic 
feet/hour (or 280,000 BTU/hr) gas volume to be 
delivered to generator. Figure 2 chart show this 
required 280 cu.ft. can not be delivered with a ¾” or 
1” pipe. Only a 1¼” diameter pipe can safely deliver 
the 280 cu.ft. gas requirement, over a 50 foot 
distance. 
 
INSTALLER’S RESPONSIBILITY: Use Figure 1 
chart to learn cubic feet/hour value of generator to 
be installed. Use Figure 2 chart to learn minimum 
pipe size diameter and maximum distance from 
gas meter, to insure sufficient fuel volume from 
natural gas meter to generator set. 
 
CRITICAL POINTS FOR A PROPER
NATURAL GAS INSTALLATION
Before natural gas fuel line plans are made, call
your natural gas supplier, give information on the 
amount of cubic feet/hour and the BTU’s/hour that 
generator will use, and ask if natural gas meter and 
primary regulator, is adequate for your natural gas 
generator. Natural gas companies have different 
meters for increasing BTU gas demands. 
 
Check the natural gas primary regulator,
connected at natural gas meter output. The correct 
primary regulator is set at 6 to 8 inches water column 
(4 to 4½ ounces pressure or 0.19 to 0.26 PSI). The 
existing primary regulator (for other gas appliances) 
may be too small to run your gas driven generator. 
 
A dedicated natural gas fuel line and primary
gas regulator (if required) is mandatory for proper 
operation. 
 
A flexible natural gas fuel line is furnished for
installation between utility gas line and generator for 
input. 
 
CAUTION: Make sure this flexible fuel line is 
installed in horizontal position without bends. A 
bend of any kind in this flexible line could lead to 
an eventual crack in the bend, causing a possible 
leak. See Figure 3 for a recommended installation. 
 
Make sure fuel pipe installation and connection at
generator includes an on/off manual gas valve. 
 
All new installations, plus any future repair or
troubleshooting procedures must include a natural 
gas manometer test. This test should be conducted 
after all other natural gas appliances have been 
turned on. After all appliances are running, start the 
generator. If manometer stays within 6 to 7 inches 
water column with full load applied to a proper 
running generator, it’s a good installation. (See 
Figure 3) 
If manometer reading falls below 5 inches water 
column while generator engine is cranking, or 
running, it may indicate the gas meter or primary 
regulator is too small, or the fuel pressure from gas 
supplier is inadequate. Any of these three problems 
will cause a fault in proper generator operation. 
 
If manometer reading stays within the 6 to 7 inches 
water column, but generator engine still will not start, 
or it runs erratic, it may indicate insufficient fuel 
volume due to long fuel line runs or fuel pipe 
diameter is too small. Check calculations of chart in 
Figure 1 & 2. 
 
Figure 3 
NOTE: After completion of all gas tests, remove 
manometer and replace blank plug, using fresh pipe 
sealant. 
 
For additional precautions, a manual fuel shut-off
valve should also be installed inside the building, for 
those locations with inside gas meters. 
 
Climates that have snow and ice build-up, along
with sub-zero temperatures, should have gas fuel 
piping protection against freezing. The generator 
end of the hard piping installation should include a 
sediment trap to drain any condensation, and a line 
filter. (See Figure 3) 
 
Best installations happen when electric utility
meter and gas meter are close together, as it results 
in short runs for both electric wires and fuel lines. 
When these two utilities are far apart, always choose 
to locate gen-set close to the gas meter, as installation 
Sediment Trap
Dedicated
Natural Gas
Fuel Line
Manometer
Reading
Must Be 6”
to 7” Water
Column
Gas Fuel To
Generator
On/Off Valve
Furnished
Flexible
Gas Pipe
(without
bends or
angles)
Manometer Port: Remove
Blank Plug And Insert
Manometer Plug
Line Filter
