Generac Power Systems PowerPact G0065201 Installation Manuallines page 23

Fuel Line Sizing
Selecting the correct size fuel line is crucial to the proper
operation of the unit. The generator inlet size has no
bearing on the size gas pipe to be used.
For further information refer to NFPA 54 for NG or NFPA
58 for LP.
Measure the distance from the generator to the gas
source.
Natural Gas Pipe Sizing
To properly use this chart, find the kVA rating of the
generator in the left column, and trace to the right. The
number to the right is the maximum length (measured in
feet / meters) allowed for the pipe sizes on top. The pipe
sizes are measured by inside diameter (ID) to include
any fittings, valves (must be full flow), elbows, tees or
angles.
kVA 0.75 in (19 mm)
5 50 ft. (15 m)
For 5–7 in. of water column (9–13 mm mercury).
LP Vapor Pipe Sizing
To determine correct LP Vapor pipe size, find the kVA
rating of the generator in the left column, and trace to the
right. The number to the right is the maximum length
(measured in meters/feet) allowed for the pipe sizes on
top. The pipe sizes are measured by inside diameter (ID)
to include any fittings, valves (must be full flow), elbows,
tees or angles.
kVA
5.6
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. The generator inlet
size has no bearing on the proper gas pipe size.
The gas supply and pipe MUST be sized at 125% Load
BTU / megajoule rating.
Installation Guidelines for 50 Hz PowerPact™
Table 5-1. Natural Gas Pipe Sizing
Pipe Size
1 in (25 mm) 1.25 in (32 mm)
150 ft. (16 m) 600 ft. (183 m)
Table 5-2. LP Vapor Pipe Sizing
Pipe Size
0.75 in (19 mm) 1 in (25 mm)
165 ft. (50 m) 450 ft. (137 m)
Fuel Conversion/Gas Connections
IMPORTANT NOTE: The generator should be plumbed
directly from the source, not off the end of an existing
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.
1.5 in (38 mm)
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NOTE: Pipe sizes are using a second stage regulator.
NOTE: The minimum LP tank size is 250 gallons (946 L),
unless unit calculations dictate use of a larger tank.
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.
1.25 in (32 mm)
2 in (51 mm)
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