Fuel Line Sizing; Natural Gas Pipe Sizing; Lp Vapor Pipe Sizing; Summary - Generac Power Systems PowerPact 7.5 kW Installation Manuallines

Fuel Line Sizing

Selecting the correct size fuel line is crucial to the proper
operation of the unit.
For further information on LP and NG installation
requirements, refer to NFPA 54 or ICC IFGC.
Measure the distance from the generator to the gas source.

Natural Gas Pipe Sizing

See Table 5-1. To determine correct NG pipe size, find
the desired pipe size in the first row of the table. The
number below is the maximum length, or run, (measured
in meters/feet) allowed for the selected pipe size. The
pipe sizes are measured by inside diameter (ID) to
include any fittings, valves (must be full flow), elbows,
tees or angles.
Pipe Size 0.5 in (13 mm)
Maximum Run
For 5–7 in. of water column (9–13 mm mercury).

LP Vapor Pipe Sizing

IMPORTANT NOTE: The generator inlet size does not
dictate the size of gas pipe to be used!
See Table 5-2. To determine correct LP Vapor pipe size,
find the desired pipe size in the first row of the table. The
number below is the maximum length, or run, (measured
in meters/feet) allowed for the selected pipe size.
Pipe Size 0.5 in (13 mm)
Maximum Run
NOTE: Pipe sizes are using a second stage regulator.
NOTE: Consult with the LP fuel provider to determine
the minimum tank size required for the installation.
Vertical tanks, which are measured in pounds (or
kilograms), will not usually meet the minimum tank size
requirement. A 1050 lb (476 kg) vertical tank size
minimum is required.
Installation Guidelines for 60 Hz PowerPact™
Table 5-1. Natural Gas Pipe Sizing
NG Pipe Size: 7.5 kW Units
0.75 in (19 mm)
10 ft. (3 m) 60 ft. (15 m)
Table 5-2. LP Vapor Pipe Sizing
LP Vapor Pipe Size: 7.5 kW Units
0.75 in (19 mm)
35 ft. (11 m) 175 ft. (53 m)
Fuel Conversion/Gas Connections
IMPORTANT NOTE: The generator should be plumbed
directly from the source, not off the end of an existing low
pressure system.
NOTE: When measuring the pipe length, add 2.5 ft (0.76
m) for every angle or bend in the pipe to the overall
required length of pipe needed.
1 in (25 mm) 1.25 in (32 mm)
200 ft. (16 m) 750 ft. (183 m)
The pipe sizes are measured by inside diameter (ID) to
include any fittings, valves (must be full flow), elbows,
tees or angles.
1 in (25 mm) 1.25 in (32 mm)
600 ft. (183 m)

Summary

Incorrect gas pipe sizing is one of the most commonly
made mistakes. A properly sized gas pipe is critical to the
proper operation of the generator. Generator inlet size
cannot compensate for improper gas pipe size.
The gas supply and pipe MUST be sized at 100% Load
BTU / megajoule rating.
1.5 in (38 mm)
—
1.5 in (38 mm)
— —
19