Trane Gas Unit Heaters カタログ
UH-PRC002-EN
11
Application Considerations
as standard equipment. However, for natural gas units, you need to specify on the order
“Natural Gas, 100 percent shutoff.”
“Natural Gas, 100 percent shutoff.”
2. All units require AGA certification or UL “listed” controls. Our units are AGA certified and meet
this requirement.
3. Models with inputs of 150,000 to 400,000 Btu require “mechanical exhaust” and a “safety
interlock.” For our units, this means a power vented or drafter-equipped unit. In both instances,
if the flue vent fan (factory or field installed) does not get up to speed, the unit will not fire,
satisfying the safety interlock portion.
if the flue vent fan (factory or field installed) does not get up to speed, the unit will not fire,
satisfying the safety interlock portion.
FM Requirements
1.
All units must be AGA certified or UL listed. Our units are AGA certified.
2. The high limit control must be in a circuit, the voltage of which does not exceed 120 Vac. All of
our high limits would meet this requirement.
The specific requirement for an “IRI or FM Gas Train,” while it applies to direct and indirect-fired
gas heating equipment as well as oil-fired, comes into play only with units having an input in excess
of 400,000 Btu. This may be one of the reasons why the majority of gas heating equipment
manufacturers (indirect-fired) limit their largest individual furnace to 400,000 Btu.
gas heating equipment as well as oil-fired, comes into play only with units having an input in excess
of 400,000 Btu. This may be one of the reasons why the majority of gas heating equipment
manufacturers (indirect-fired) limit their largest individual furnace to 400,000 Btu.
Minimum/Maximum Gas Inlet Pressures
Gas valves are suitable to a maximum inlet pressure of 0.5 psi (14 inches water column) on natural
gas. If the main gas supply pressure is greater than 14 inches wc, a step-down pressure regulator
must be field-installed ahead of the gas valve. Minimum inlet pressure for natural gas units is
5 inches wc.
gas. If the main gas supply pressure is greater than 14 inches wc, a step-down pressure regulator
must be field-installed ahead of the gas valve. Minimum inlet pressure for natural gas units is
5 inches wc.
For LP (propane) gas, the minimum inlet pressure is 11.0 inches wc and the maximum inlet pressure
is 14.0 inches wc.
is 14.0 inches wc.
High Pressure Regulators—Natural Gas Only
The Trane indoor gas heating products contained in this catalog are designed to operate at a
pressure of 3.5-inch wc (water column) when firing on natural gas. This is the “manifold” pressure
or that which is present at the burner orifices. All five- and six-function valves provide a built-in
pressure regulator which is capable of reducing “supply” pressures from a maximum of 14-inch
wc (1/2 psi) down to 3.5-inch wc on the leaving side of the valve. The valve typically “drops” about
1-1/2 inches so the minimum supply pressure is 5-inch wc.
pressure of 3.5-inch wc (water column) when firing on natural gas. This is the “manifold” pressure
or that which is present at the burner orifices. All five- and six-function valves provide a built-in
pressure regulator which is capable of reducing “supply” pressures from a maximum of 14-inch
wc (1/2 psi) down to 3.5-inch wc on the leaving side of the valve. The valve typically “drops” about
1-1/2 inches so the minimum supply pressure is 5-inch wc.
Whenever supply pressures exceed 14 inches wc, a high pressure regulator should be selected. We
supply a Rockwell regulator which is fitted with pressure springs and capacity orificing to meet the
requirements of each specific job. In order to select the proper spring/orifice combination, we need
to know what the supply pressure is on that particular job and the input size of the unit being
ordered. More than one unit can be run from one regulator; however, we recommend that each unit
have its own regulator.
supply a Rockwell regulator which is fitted with pressure springs and capacity orificing to meet the
requirements of each specific job. In order to select the proper spring/orifice combination, we need
to know what the supply pressure is on that particular job and the input size of the unit being
ordered. More than one unit can be run from one regulator; however, we recommend that each unit
have its own regulator.
We require that the “job” supply pressure be included on all jobs requiring high pressure
regulators along with the unit size.
regulators along with the unit size.
displays the regulators range as it pertains to inlet
pressure and MBh. A dash (
—)
requires the customer to contact a local utility or an industrial supply
house.
These devices are not available from Trane for LP gas. LP accessories must be secured from the
gas supplier/ supply house.
gas supplier/ supply house.