Gas Supply - Empire Comfort Systems VFD20MS30N-1 Installation Instructions And Owner's Manual

Check all local codes for requirements, especially for the size and
type of gas supply line required.
RECOMMENDED GAS PIPE DIAMETER
Schedule 40 Pipe
Pipe
Inside Diameter
Length
Natural
0-10 feet 1/2"
0-3 meters 12.7 mm
10-40 feet 1/2"
4-12 meters 12.7 mm
40-100 feet 1/2"
13-30 meters 12.7 mm
100-150 feet 3/4"
31-46 meters 19 mm
NOTICE: Never use plastic pipe. Check to confirm whether your
local codes allow copper tubing or galvanized.
NOTICE: Since some municipalities have additional local codes, it
is always best to consult your local authority and installation code.
Installing a New Main Gas Shut-Off Valve
Each appliance should have its own manual gas shut-off valve.
A manual main gas shut-off valve should be located in the vicinity
of the unit. Where none exists, or where its size or location is not
adequate, contact your local authorized installer for installation
or relocation.
Compounds used on threaded joints of gas piping shall be resistant
to the action of liquefied petroleum gases. The gas lines must be
checked for leaks by the installer. This should be done with a soap
solution watching for bubbles on all exposed connections, and if
unexposed, a pressure test should be made.
Never use an exposed flame to check for leaks. Appliance must
be disconnected from piping at inlet of control valve and pipe
capped or plugged for pressure test. Never pressure test with
appliance connected; control valve will sustain damage!
A gas valve and ground joint union should be installed in the gas
line upstream of the gas control to aid in servicing. It is required by
the National Fuel Gas Code that a drip line be installed near the gas
inlet. This should consist of a vertical length of pipe tee connected
into the gas line that is capped on the bottom in which condensation
and foreign particles may collect.
The use of the following gas connectors is recommended:
— ANS Z21.24 Appliance Connectors of Corrugated Metal Tubing
and Fittings
— ANS Z21.45 Assembled Flexible Appliance Connectors of Other
Than All-Metal Construction
The above connectors may be used if acceptable by the authority
having jurisdiction The Commonwealth of Massachusetts requires
that a flexible appliance connector cannot exceed three feet in length.
Page 8

GAS SUPPLY

Tubing, Type L
Outside Diameter
Propane Natural Propane
3/8" 1/2"
9.5 mm 12.7 mm 9.5 mm
1/2" 5/8"
12.7 mm 15.9 mm 12.7 mm
1/2" 3/4"
12.7 mm 19 mm 12.7 mm
1/2" 7/8"
12.7 mm 22.2 mm 19 mm
3/8"
1/2"
1/2"
3/4"
Pressure Testing of the Gas Supply System
1. To check the inlet pressure to the gas valve, a 1/8" (3 mm) N.P.T.
plugged tapping, accessible for test gauge connection, must
be placed immediately upstream of the gas supply connection
to the appliance.
2. The appliance and its 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
1/2 psig (3.5 kPa).
3. The appliance must be isolated from the gas supply piping
system 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 1/2 psig (3.5 kPa).
If one of the above procedures results in pressures in excess
of 1/2 psig (14" w.c.) (3.5 kPa) on the appliance gas valve, it
will result in a hazardous condition.
Checking Manifold Pressure
Natural Gas will have a manifold pressure of approximately
3.5" w.c. (.871 kPa) for maximum input or 1.7" w.c. (.423 kPa) for
minimum input at the pressure regulator outlet with the inlet pressure
to the pressure regulator from a minimum of 4.5" w.c. (1.245 kPa)
for the purpose of input adjustment to a maximum of 10.5" w.c.
(2.614 kPa). Propane Gas will have a manifold pressure approximately
10.0" w.c. (2.49 kPa) for maximum input or 6.3" w.c. (1.568 kPa) for
minimum input at the pressure regulator outlet with the inlet pressure to
the pressure regulator from a minimum of 11.0" w.c. (2.739 kPa) for the
purpose of input adjustment to a maximum of 13.0" w.c. (3.237 kPa).
NOTICE: The gas control is equipped with a captured screw type
pressure test point, therefore it is not necessary to provide a 1/8"
test point up stream of the control.
A test gauge connection is located downstream of the gas appliance
pressure regulator for measuring gas pressure. The connection is
a 1/8 inch (3 mm) N.P.T. plugged tapping.
Figure 1
WARNING
42605-3-0621