FIGURE 5 - Gas
connection is at the
pipe nipple that extends
outside the cabinet
Illustration shows
both a vertical and
horizontal gas supply;
requirements are the
same.
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Install a ground joint union and manual shutoff valve upstream of the unit
control system, as shown in
FIGURE 5
. Installation of a trap with a mini-
mum 3” (76mm) drip leg is required.
7.1.2
Gas Connections
Leak-test all connections by brushing on a leak-detecting solution.
WARNING: All components of a gas supply system must
be leak tested prior to placing equipment in service.
NEVER TEST FOR LEAKS WITH AN OPEN FLAME. Failure
to comply could result in personal injury, property damage
or death.
Gas Connection
Size
inches
130,180
1/2
260, 310
3/4
7.1.3 Valve Outlet or
Orifice Pressure Setting
Measuring valve outlet gas pressure cannot be done until the heater is in
operation. It is included in the steps of the “Check-Test-Start” procedure in
Paragraph 11. The following warnings and instructions apply.
WARNING: Valve outlet gas pressure must never exceed
3.5” w.c. for natural gas and 10” w.c. for propane gas.
For Natural Gas
:
When the heater leaves the factory, the combination gas
valve is set so that the valve outlet gas pressure for a single-stage valve
is regulated to 3.5” w.c. Inlet supply pressure to the valve for natural gas
must be a minimum of 5” w.c. or as noted on the rating plate and a maxi
-
mum of 14” w.c.
For Propane:
The heater is shipped factory equipped for use with natural
gas. A propane conversion kit is included. Follow the instructions in Para-
graph 7.1.4 to convert for use with propane.
At startup, measure the valve outlet pressure. Refer to the pressure chart
on page 12 for correct outlet pressure.
When using propane, the inlet supply pressure to the valve must be a mini-
mum of 11” w.c. and a maximum of 14” w.c.
NOTE:
A gas conversion kit
for changing from natural gas
to propane is included with
each heater. See Paragraph
7.1.4 for conversion instruc-
tions.
7. Mechanical
(cont’d)
7.1 Gas Piping and
Pressure (cont’d)
The unit is equipped with a nipple
that extends outside the cabinet.
The gas connection is either 1/2”
or 3/4”.
Form I-UEAS, Page 10