Aerco Benchmark G-00-711, Руководство пользователя

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INSTALLATION
2-7
string. It therefore does not need to be closed for
the boiler start sequence to begin but does need
to be closed within 30 seconds for the boiler to
fire. The delayed interlock is usually connected
to the proving device of the auxiliary equipment
started by the auxiliary relay. These interlocks
are labled Delayed Int'lock and their location is
on the inside of the control panel door. The
interlock circuit is 120 VAC, and comes factory
pre-wired closed. See figure 2.12.
2.8.2 REMOTE ENABLE/ DISABLE
An enable/disable circuit is provided for remote
start and stop. The circuit is labeled
Enable/Disable and is located on the inside of
the control panel door. The circuit is 120 VAC,
and comes factory pre-wired closed (jumped).
See figure 2.12.
2.9 FAULT RELAY WIRING
The fault relay contains a set of normally open
dry contacts, rated for 5 amps at 120 VAC and 5
amps at 30 VDC that close on any fault
condition. The relay will remain energized until
the fault is cleared and the CLEAR button is
depressed. The fault relay connections are
shown in Figure 2.11.
Figure 2.12
Interlock Wiring
2.10 FLUE GAS VENT INSTALLATION
The AERCO Venting and Combustion Air Guide,
GF-2050, must be consulted before any flue gas
vent or inlet air venting is designed or installed.
U/L listed, positive pressure, watertight vent
materials as specified in AERCO’s GF-2050,
must be used for safety and code compliance.
Because the unit is capable of discharging low
temperature exhaust gases, the flue must be
pitched back to the unit a minimum of 1/4" per
foot to avoid any condensate pooling and to
allow for proper drainage.
The combined pressure drop of vent and
combustion air systems must not exceed 140
equivalent feet of 8”’ inch ducting. Fittings as
well as pipe lengths must be calculated as part
of the equivalent length.
For a natural draft installation the draft must not
exceed -0.25”/+0.25" W.C. These factors must
be planned into the vent installation. If the
maximum allowable equivalent lengths of piping
are exceeded, the unit will not operate properly
or reliably.
2.11 COMBUSTION AIR
The AERCO Venting and Combustion Air Guide,
GF-2050, MUST be consulted before any flue or
combustion supply air venting is designed or
started. Combustion air supply is a direct
requirement of ANSI 223.1, NFPA-54, 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.
The Benchmark is UL listed for 100% sealed
combustion and can be ordered with a sealed
combustion option, or can be installed using
room air as long as there is an adequate supply.
(See section 2.11.3 for more information
concerning sealed combustion air.)
If the sealed combustion air option is not being
used, an inlet screen will be attached at the
blower suction and the knockout at the top of the
unit will be and should remain in place.
The more common methods of supplying
combustion air are outlined below. For more
information concerning combustion air, consult
the AERCO GF-2050, Venting and Combustion
Air Guide.
2.11.1 COMBUSTION AIR FROM
OUTSIDE THE BUILDING
Air supplied from outside the building must be
provided through two permanent openings. Each
opening must have a free area of not less than
one square inch for each 4000 BTU boiler input.
The free area must take into account restrictions
such as louvers and bird screens.