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VII-ACCESSORIES
The accessories section describes the application of most of
the optional accessories which can be factory or field installed.
OPTIONAL ACCESSORIES section (see table of contents)
show specific size per unit.
A-LARMF Mounting Frames
When installing units on a combustible surface for downflow
discharge applications, the Z1CURB roof mounting frame is
used. The roof mounting frames are recommended in all
other applications but not required. If units are not mounted
on a flat (roof) surface, they MUST be supported under all
edges and under the middle of the unit to prevent sagging.
The units MUST be mounted level within 1/16” per linear foot
or 5mm per meter in any direction.
The assembled Z1CURB mounting frame is shown in fig
ure 16. Refer to the roof mounting frame installation instruc
tions for details of proper assembly and mounting. The roof
mounting frame MUST be squared to the roof and level be
fore mounting. Plenum system MUST be installed before
the unit is set on the mounting frame. Typical roof curbing
and flashing is shown in figure 17. Refer to the roof mount
ing frame installation instructions for proper plenum
construction and attachment.
B-Transitions
Transitions are field-provided.
C-Supply and Return Diffusers
Optional flush mount diffuser/return FD11 and extended mount
diffuser/return RTD11 are available. Refer to manufacturer's
instructions included with transition for detailed installa
tion procedures.
FIGURE 16
ASSEMBLED ROOF MOUNTING FRAME
SUPPLY AIR
OPENING
RETURN AIR
OPENING
FIGURE 17
ROOF
MOUNTING FRAME
(Extends around entire
perimeter of unit)
FIBERGLASS
INSULATION
(Furnished)
COUNTER FLASHING
(Field Supplied)
UNIT BASE
BOTTOM
RIGID INSULATION
(Field Supplied)
ROOFING
MATERIAL
CANT STRIP
(Field Supplied)
NAILER STRIP
(Furnished)
UNIT BASE RAIL
TYPICAL FLASHING DETAIL
D-Z1ECON16/20B Economizer
(Field or Factory Installed)
Economizers use outdoor air for free cooling when temper
ature and/or humidity is suitable. See figure 18.
The mixed air temperature sensor (R1) measures the sup
ply air sensible temperature. See figure 19. The outdoor air
sensible control is the default economizer control. An out
door air single sensible sensor, S175, is also provided. See
table 7 for outdoor and return air (OA and RA) sensor op
tions. Refer to instructions provided with sensors for instal
lation.
An IAQ sensor is used when demand control ventilation
(DCV) is specified. Damper minimum position can be set
lower than traditional minimum air requirements resulting in
cost savings. The IAQ sensor allows the A6 to open damp
ers to traditional ventilation requirements as room occu
pancy (CO
2
) increases.
TABLE 7
Sensors
Dampers will modulate to 55°F
discharge air (RT6) when:
Single OA Sensible
OA temperature (S175) is lower
than free cooling setpoint.
Single OA Sensible
OA temperature and humidity (A7)
is lower than free cooling setpoint.
Differential Enthalpy - 1
in OA and 1 in RA
OA temperature and humidity (A7)
is lower than RA temperature and
humidity (A62).
IAQ Sensor
CO
2
sensed (A63 ) is higher than
CO
2
setpoint.
