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High Altitude Derate
Units must be derated when installed at altitudes above
4500 feet (610 m) above sea level. At altitudes above
4500 feet (610 m), units must be derated to match the gas
manifold pressures shown in table 1.
NOTE0This is the only permissible derate for these units.
TABLE 1
Altitude ft (m)
Gas Manifold Pressure−in. w.g. (kPa)
Altitude − ft. (m)
Natural
LP (Propane
)
4501−5500 (1372−1676)
3.4 (0.85)
10.2 (2.54)
5501−6500 (1676−1981)
3.3 (0.82)
9.8 (2.44)
6501−7500 (1981−2286)
3.2 (0.80)
9.5 (2.36)
Factory−Installed Options
A−Economizer
The A56 EM1 economizer board controls economizer
operation and provides potentiometers to control
minimum
damper
position
and
enthalpy
control
adjustments. The economizer board is positioned on the
A55 M1 main control board in the unit control box. See the
Integrated Modular Control Guide for economizer
operation and adjustments.
Intake hood parts and supply air filters are shipped in the
filter section. Remove intake hood package from filter
channels. Remove filters from unit and slide into filter
channels. If the filters have a metal frame, remove the
cardboard shipping pad protecting the evaporator coil.
B−Intake Hood
The intake hood top panel is secured to the unit. The
intake hood sides, filters, and three support brackets are
shipped
unassembled
in
the
filter
compartment.
Assemble hood and install as follows:
1− Remove screws securing side flanges of top hood to
unit. See figure 8.
2− Pivot top hood open and secure sides of intake hood
to top of hood using three sheet metal screws on each
side. See figure 8.
3− Align two holes on intake hood side panel with two
holes on bottom filter bracket. See figure 9. Secure
both sides of bottom filter bracket to hood sides with
sheet metal screws.
4− Secure intake hood sides to unit.
5− Secure top filter bracket to hood top flange as shown
in figure 9. Slide filter into flanges and install spacers
on either side of filter.
FIGURE 8
INTAKE HOOD
HOOD TOP
HOOD
SIDE
UNIT
TOP SEAL
HOOD TOP
NOTE: CAULK EACH SIDE
OF TOP SEAL (FIELD PRO
VIDED)
FIGURE 9
HOOD SIDE VIEW
ALIGN VERTICAL HOLES ON
BRACKET WITH VERTICAL
HOLES ON SIDE OF HOOD
BOTTOM FILTER
BRACKET
HOOD TOP
TOP FILTER
BRACKET
FILTER
HOOD TOP SEAL
