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Benchmark 5000-6000 Boiler Installation & Startup Manual
SECTION 2: INSTALLATION
2.13 COMBUSTION AIR
The Benchmark Venting and Combustion Air Guide, TAG-0022 (GF-2050) MUST be consulted
before any flue or inlet air venting is designed or installed. Air supply is a direct requirement of
ANSI 223.1, NFPA-54, CSA B149.1 and local codes. These codes should be consulted before a
permanent design is determined.
The combustion air must be free of chlorine, halogenated hydrocarbons or other chemicals that
can become hazardous when used in gas-fired equipment. Common sources of these
compounds are swimming pools, degreasing compounds, plastic processing, and refrigerants.
Whenever the environment contains these types of chemicals, combustion air MUST be
supplied from a clean area outdoors for the protection and longevity of the equipment and
warranty validation.
If combustion air is supplied directly to the unit(s) though air duct(s), see section 2.13.1 below.
If combustion air is not supplied through air ducts, it must be supplied to the unit(s) through two
permanent openings. These two openings must have a free area of not less than one square
2
inch (6.5 cm
) for each 4000 BTUs (1.17 kW) input for each unit, or 1,500 square inches
2
(0.96 m
) of free area for the BMK 6000, or 1,250 square inches (0.81 m
BMK 5000. The free area must take into account restrictions such as louvers and bird screens.
For Canada installations, refer to the requirements specified in CSA B149.1-10, sections 8.4.1
and 8.4.3.
NOTE:
The source of internal combustion air must be positive or neutral in pressure. Negative
pressure inside a boiler room may have an adverse effect on combustion equipment.
2.13.1 DUCTED COMBUSTION AIR
For ducted combustion air installations, the air ductwork must be attached directly to the air inlet
connection on the sheet metal enclosure. Consult the Benchmark Venting and Combustion Air
Guide, TAG-0022 (GF-2050) when designing combustion air ducting.
In a ducted combustion air application, the combustion air ducting pressure losses must be
taken into account when calculating the total maximum allowable venting run. When using the
unit in a ducted combustion air configuration, each unit must have a minimum 14 inch (35.56
cm) diameter connection at the unit.
2.14 BENCHMARK PUMP RELAY
All Benchmark units ship with a pump relay (P/N 69102-3) as standard equipment. The pump
relay allows the user to turn a pump on/off and open/close a motorized valve as the boiler
cycles on and off on demand. The Pump Delay Timer feature allows the user to keep the pump
running and keep the motorized valve open for up to 30 minutes after the boiler has shut down
and the demand is satisfied. See Figures 2-16 and 2-17 for wiring details.
The pump relay is attached to the outside of the power box, as shown below. Boilers equipped
with the pump relay have a label on the power box cover adjacent to the relay.
OMM-0123_E • GF-207 • 12/17/2019
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
2
) of free area for the
Page 32 of 95
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