Daikin DC97MC, Руководство по установке

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32
G
AS
P
IPING
C
ONNECTIONS
T
O AVOID POSSIBLE UNSATISFACTORY OPERATION OF EQUIPMENT
DAMAGE DUE TO UNDERFIRING OR EQUIPMENT
,
USE THE PROPER SIZE
OF NATURAL
/
PROPANE GAS PIPING NEEDED WHEN RUNNING PIPE FROM
THE METER
/
TANK TO THE FURNACE
.
WARNING
The gas piping supplying the furnace must be properly sized
based on the gas flow required, specific gravity of the gas,
and length of the run. The gas line installation must comply
with local codes, or in their absence, with the latest edition
of the National Fuel Gas Code, NFPA 54/ANSI Z223.1 or CAN/
CSA B149.1-15 in Canada.
Natural Gas Capacity of Pipe In Cubic Feet of Gas Per Hour (CFH)
Nominal
½ ¾ 1 1¼ 1½ 2 2½
Actual ID:
0.622 0.824 1.049 1.380 1.610 2.067 2.469
Length (ft)
10 170 360 678 1390 2090 4020 6400
20 118 247 466 957 1430 2760 4400
30 95 199 374 768 1150 2220 3530
40 81 170 320 657 985 1900 3020
50 72 151 284 583 873 1680 2680
60 65 137 257 528 791 1520 2430
70 60 126 237 486 728 1400 2230
80 56 117 220 452 677 1300 2080
90 52 110 207 424 635 1220 1950
100 50 104 195 400 600 1160 1840
125 44 92 173 355 532 1020 1630
150 40 83 157 322 482 928 1480
175 37 77 144 296 443 854 1360
200 34 71 134 275 412 794 1270
250 30 63 119 244 366 704 1120
Capacity in Cubic Feet of Gas per Hour
This chart refers to natural gas w ith an inlet pressure of less than 2 psi and a
pressure drop of 0.5" W.C. Specific gravity is 0.60.
Pipe Size (in.)
CFH = BTUH Furnace Input
Heating Valve of Gas (BTU/Cubic Foot)
To connect the furnace to the building’s gas piping, the in-
staller must supply a ground joint union, drip leg, manual
shutoff valve, and line and fittings to connect to gas valve. In
some cases, the installer may also need to supply a transition
piece from 1/2" pipe to a larger pipe size.
The following stipulations apply when connecting gas piping.
Refer to
Gas Piping Connections figure for typical gas line
connections to the furnace.
•
Gas piping must be supported external to the furnace
cabinet so that the weight of the gas line does not
distort the burner rack, manifold or gas valve.
•
Use black iron or steel pipe and fittings for building
piping. Where possible, use new pipe that is properly
chamfered, reamed, and free of burrs and chips. If old
pipe is used, be sure it is clean and free of rust, scale,
burrs, chips, and old pipe joint compound.
•
Use pipe joint compound on male threads ONLY. Always
use pipe joint compound (pipe dope) that is APPROVED
FOR ALL GASES. DO NOT apply compound to the first
two threads.
•
Use ground joint unions.
•
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.
•
A line pressure test port is provided on the gas
valve. If desired, install a 1/8" NPT pipe plug fitting,
accessible for test gage connection, immediately
upstream of the gas supply connection to the furnace.
•
Always use a back-up wrench when making the
connection to the gas valve to keep it from turning.
The orientation of the gas valve on the manifold must
be maintained as shipped from the factory. Maximum
torque for the gas valve connection is 375 in-lbs;
excessive over-tightening may damage the gas valve.
•
Install a manual shutoff valve between the gas meter
and unit within six feet of the unit. If a union is installed,
the union must be downstream of the manual shutoff
valve, between the shutoff valve and the furnace.
•
Tighten all joints securely.
•
Connection method must be in compliance with all
local and national codes. US: National Fuel Gas Code
(NFGC) NFPA 54-2012/ANSI Z223.1-2012 and the
Installation Standards, Warm Air Heating and Air
Conditioning Systems ANSI/NFPA 90B.
In Canada, CANADA: National Standard of Canada,
Natural Gas and Propane Installation Code
(NSCNGPIC) CSA B149.1-15.
Connect the furnace to the building piping by one of the
following methods:
–
Rigid metallic pipe and fittings.
–
Semi-rigid metallic tubing and metallic fittings.
Aluminum alloy tubing must not be used in exterior
locations. In order to seal the grommet cabinet
penetration, rigid pipe must be used to reach the
outside of the cabinet. A semi-rigid connector to
the gas piping may be used from there.
•
Use listed gas appliance connectors in accordance with
their instructions. Connectors must be fully in the same
room as the furnace.
•
Protect connectors and semirigid tubing against physical
and thermal damage when installed. Ensure aluminum-
alloy tubing and connectors are coated to protect
against external corrosion when in contact with masonry,
plaster, or insulation, or subjected to repeated wetting
by liquids such as water (except rain water), detergents,
or sewage.