59MN7C: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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Gas piping must be installed in accordance with national and local
codes. Refer to current edition of NFGC in the U.S.A. Refer to current
edition of NSCNGPIC in Canada.
Installations must be made in accordance with all authorities having
jurisdiction. If possible, the gas supply line should be a separate line
running directly from meter to furnace.
NOTE: Use a back-up wrench on the inlet of the gas valve when
connecting the gas line to the gas valve.
The gas supply pressure shall be within the maximum and minimum
inlet supply pressures marked on the rating plate with the furnace
burners ON and OFF.
Gas entry can be from left or right side, or top panel. See Fig. 29 and
Fig. 31.
A11338A
Fig. 29 – Gas Entry
A230050
Fig. 30 – Alternate Gas and Electric Entry
NOTE: Top plate may be field drilled for alternate gas and 115 VAC
electric entry.
Refer to Table 8 for recommended gas pipe sizing. Risers must be used
to connect to furnace and to meter. Support all gas piping with
appropriate straps, hangers, etc. Use a minimum of one hanger every 6
ft. (2 M). Joint compound (pipe dope) should be applied sparingly and
only to male threads of joints. Pipe dope must be resistant to the action
of propane gas.
Table 8 – Maximum Capacity of Pipe
NOTE:
*Cubic ft. of natural gas per hr for gas pressures of 0.5 psig
(14-in. w.c.) or less and a pressure drop of 0.5-in. w.c. (based on a 0.60
specific gravity gas). Ref: Chapter 6 current edition of NFPA 54/ANSI
Z223.1.
When a flexible connector is used, black pipe shall be installed at the
furnace gas control valve and extend a minimum of 2-in. (51 mm)
outside the furnace.
For direct vent (2-pipe) applications, seal the gas pipe opening to prevent
air leakage.
Remove the required knockout or plug. Install the grommet in the
opening. Then insert the gas pipe. The grommet is included in the loose
parts bag.
Piping should be pressure and leak tested in accordance with the current
addition of the NFGC in the United States, local, and national plumbing
and gas codes before the furnace has been connected.
Refer to current edition of NSCNGPIC in Canada. After all connections
have been made, purge lines and check for leakage at furnace prior to
operating furnace.
PRESSURE TESTING ABOVE ½ psig:
The furnace and it’s individual shut-off valve must be disconnected from
the gas supply piping system during any pressure testing of that system
at test pressures in excess of ½ psig (3.5 kPa).
PRESSURE TESTING BELOW ½ psig:
The furnace must be isolated from the gas supply piping by closing its
individual manual shut-off valve during any pressure testing of the gas
supply piping system at test pressures equal to or less than ½ psig (3.5
kPa).
An accessible manual equipment shutoff valve MUST be installed
external to furnace casing and within 6 ft. (2 M) of furnace.
Install a sediment trap externally in the riser leading to furnace as shown
in Fig. 31. Connect a capped nipple into lower end of tee. Capped nipple
should extend below level of furnace gas controls. Place a ground joint
CAUTION
!
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in furnace damage.
Connect gas pipe to furnace using a backup wrench to avoid damaging
gas controls and burner misalignment.
NOTICE
!
In the State of Massachusetts:
1. Gas supply connections MUST be performed by a licensed
plumber or gas fitter.
2. When flexible connectors are used, the maximum length shall not
exceed 36 in. (915 mm).
3. When lever handle type manual equipment shutoff valves are
used, they shall be T-handle valves.
4. The use of copper tubing for gas piping is NOT approved by the
State of Massachusetts.
Gas Pipe Grommet Required
For Direct Vent Applications
Left Side Gas Entry. Gas Pipe
Grommet Required For Direct
Vent Applications.
Nominal: 1/2 (12.7) 3/4 (19.0) 1 (25.4)
1-1/4
(31.8)
1-1/2
(38.1)
Actual ID: 0.622 0.824 1.049 1.380 1.610
Length (ft) Capacity in Cubic Feet of Gravity
10 (3.0)
172 360 678 1390 2090
20 (6.0)
118 247 466 957 1430
30 (9.1)
95 199 374 768 1150
40 (12.1)
81 170 320 657 985
50 (15.2)
72 151 284 583 873
Gas Pressure Natural (in W.C.) Propane (in W.C.)
Maximum
13.8
Minimum
4.5” 12”
WARNING
!
FIRE OR EXPLOSION HAZARD
A failure to follow this warning could result in personal injury, death,
and/or property damage.
If local codes allow the use of a flexible gas appliance connector,
always use a new listed connector. Do not use a connector which has
previously served another gas appliance. Black iron pipe shall be
installed at the furnace gas control valve and extend a minimum of 2-in.
(51 mm) outside the furnace.
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