Gillette Generators SPP-180 - Manual (Page 14)

PAGE 14
LPG GAS FUEL
This home generator system has been set up at the
factory for natural gas fuel, unless it has been
specifically ordered for vapor withdrawal liquid
propane gas (LPG). This installation/operation guide
will explain the factory LPG system. Additional
information is available upon request for field
conversion from one fuel to the other.
LPG fuel is typically at farms or remote areas where
there is no natural gas fuel.
LPG must be a vapor withdrawal system (the
generator will not work on liquid withdrawal
systems). Proper LPG is clean and free of moisture
or particulate matter. It consists of a propane HD5
grade with minimum 2500 BTU’s per cubic foot
energy rating. A typical blend is 5% propylene and
butane plus a minimum 90% propane.
Required LPG vapor withdrawal fuel pressure is
11-14 inches water column at (6-6½ ounces) 2500
BTU’s per cubic feet.
Figure 4
*BTU VALUES BASED ON 2500 BTU’S PER CUBIC FEET GAS
SUPPLIER MAY NEED TO KNOW LPG CONSUMPTION AT FULL
LOAD, IN MEASUREMENTS OF CUBIC FT./HOUR OR BTU/HOUR.
Figure 5
CAUTION: It is critically important to understand,
that as a specific fuel line pipe diameter is extended
in length, its ability to carry the volume of gas,
diminishes in direct proportion.
EXAMPLE 1: In reading the charts: A model SPS-120,
12 KW generator is to be installed 50 feet from LPG
fuel tank. Figure 4 chart shows this model to require
87 cubic feet per hour, gas volume to be delivered to
generator. Figure 5 chart shows the required 87
cubic feet can be delivered over a 50 foot distance
with ¾” diameter fuel pipe.
EXAMPLE 2: A model SPP-180, 18 KW generator set
is to be installed 70 feet from LPG tank. In reading
the charts, fig. 4 chart show this model to require 135
cu.ft./hr. gas volume to be delivered to generator.
Fig. 5 chart shows the required 135 cu.ft. can be
delivered over a 50 ft. distance with a 1” diameter
fuel pipe.
INSTALLER’S RESPONSIBILITY: Use Figure 4
chart to learn cubic feet/hour value of generator to
be installed. Use Figure 5 chart to learn minimum
pipe size diameter and maximum distance from
LPG tank to insure sufficient fuel volume from
LPG tank to generator.
CRITICAL POINTS FOR A PROPER LPG
GAS INSTALLATION
Before LPG fuel line plans are made, call your
LPG supplier, give information on the amount of cubic
feet/hour (Figure 4) and BTU’s/hour (Figure 5) that
your generator will use, and ask about local codes
and regulations concerning LPG fuel connected to
generators.
Only LPG vapor withdrawal (not LPG liquid
withdrawal) will work on these generators. Make
sure the LPG tank has the correct fuel.
LPG fuel pressure must be 6 ounce pressure (11
-14 inches water column) delivered to the generator.
Often new LPG tanks or existing LPG tanks
already located at the installation site, have a pre-
installed, primary regulator set for 250 PSI and
intended for home heating and cooking. This is
wrong for generator fuel.
The LPG fuel tank must have a dedicated primary
LPG fuel regulator mounted at the tank fuel outlet
point, and set for 6 ounce pressure (11-14 inches
water column). A direct, dedicated fuel line
connected to the 6 ounce fuel tank primary regulator,
must be connected directly to the generator mounted,
secondary regulator, also, set at 6 ounce pressure.
LPG FUEL CONSUMPTION AT FULL LOAD
Gen. Model Gen. KW Cubic Ft./Hr BTU/Hr. *
SPS-120 12.0 87 220,000
SPP-180 18.0 135 337,500
LPG FUEL LINE MAXIMUM DIAMETERS & LENGTHS
Pipe Length
In Feet
Allowed Distance From LPG Tank
to Gen-Set
0-
10
11-
20
21-
30
31-
40
41-
50
51-
60
61-
70
71-
80
81-
90
P
ip
e
D
ia
m
e
te
r
In
In
ch
e
s
½ 110 76 61 --- --- --- --- --- ---
¾ 227 157 126 107 95 87 78 70 62
1 428 293 236 201 179 164 151 138 129
1¼ 807 523 445 379 338 309 285 255 242
Cubic feet of LPG (vapor withdrawal) that can
safely be carried in it’s matching pipe diameter.