Daikin DCG Series Installation And Maintenance Manual page 12

INLET GAS PRESSURE
NATURAL Min. 5.0" W.C., Max. 10.0" W.C.
PROPANE Min. 11.0" W.C., Max. 14.0" W.C.
Inlet Gas Pressure Must Not Exceed the Maximum Value Shown in Table Above.
The minimum supply pressure should not vary from that shown in
the table above because this could prevent the unit from having
dependable ignition. In addition, gas input to the burners must
not exceed the rated input shown on the rating plate. Overfiring
of the unit could result in premature heat exchanger failure.
P
IPING
IMPORTANT NOTE: To avoid possible unsatisfactory operation or
equipment damage due to under firing of equipment, do not un-
dersize the natural/propane gas piping from the meter/tank to the
unit. When sizing a trunk line, include all appliances on that line
that could be operated simultaneously.
The rating plate is stamped with the model number, type of gas
and gas input rating. Make sure the unit is equipped to operate on
the type of gas available. The gas line installation must comply
with local codes, or in the absence of local codes, with the latest
edition of the National Fuel Gas Code NFPA 54/ANSI Z223.1.
Natural Gas Connection
Natural Gas Capacity of Pipe
in Cubic Feet of Gas Per Hour (CFH)
Length of
Nominal Black Pipe Size (inches)
Pipe in Feet
1/2
10 132
20 92
30 73
40 63
50 56
60 50
70 46
80 43
90 40
100 38
Pressure= .50 PSIG or less and Pressure Drop of 0.3" W.C.
(Based on 0.60 Specific Gravity Gas)
BTUH Furnace Input
CFH =
Heating Value of Gas (BTU/Cubic Foot
Refer to the Proper Piping Practice drawing for the general layout
at the unit. The following rules apply:
1. Use black iron pipe and fittings for the supply piping. The
use of a flex connector and/or copper piping is permitted
as long as it is in agreement with local codes.
2. Use pipe joint compound on male threads only. Pipe joint
compound must be resistant to the action of the fuel used.
3. Use ground joint unions.
4. Install a drip leg to trap dirt and moisture before it can
enter the gas valve. The drip leg must be a minimum of
three inches long.
3/4 1 1 1/4 1 1 /2
278 520 1050 1600
190 350 730 1100
152 285 590 980
130 245 500 760
115 215 440 670
105 195 400 610
96 180 370 560
90 170 350 530
84 160 320 490
79 150 305 460
5. Use two pipe wrenches when making connection to the
gas valve to keep it from turning.
6. Install a manual shut-off valve in a convenient location
(within six feet of unit) between the meter and the unit.
7. Tighten all joints securely.
8. The unit must be connected to the building piping by one
of the following methods:
• Rigid metallic pipe and fittings
• Semirigid metallic tubing and metallic fittings (Aluminum
alloy tubing must not be used in exterior locations)
• Listed gas appliance connectors used in accordance with
the terms of their listing that are completely in the same
room as the equipment
• In the prior two methods above the connector or tubing
must be protected from physical and thermal damage.
Aluminum alloy tubing and connectors must be coated
to protect against external corrosion when in contact with
masonry, plaster or insulation or are subject to repeated
wettings by liquids (water - not rain water, detergents or
sewage).
GAS INLET LOCATION (3/4" NPT)
46-1/10" 46-1/10" 46-1/10"
74-11/12"
DOOR
PROVIDE
CLEARANCE
FOR REMOVAL OF
ACCESS PANELS
MANUAL
SHUT OFF
VALVE
PROPER PIPING PRACTICE
10
HOOD LOCATED
INSIDE HEAT SECTION
DURING SHIPPING
DRIP LEG
GROUND
JOINT
UNION