Reznor CAUA Option - Installation - Mixing Box Installation - Manual (Page 4)

Form I-CAUA-MB, P/N170640R2 Page 4
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0514 Form I-CAUA-MB (Version B.1)
Replacement Filters
Mixing
Box Motor
Control
Description Operating
Mode
Application
(NOTE: Cooling mode requires optional cased cooling coil.)
Option Code(s)
GA1,
GA2,
GA3,
GA4,
GA5,
GA6,
GA7,
GA8,
GA9.
GB2
None
2-Position
Damper
Motor
Heating
only or
Heating &
Cooling
When the unit is operating, the outside air damper is open.
GC3C
2-Position
Damper
Motor with
2-Position
Enthalpy
Control
Cooling
only
To minimize cooling energy consumption and equipment cycling, when the
sensor detects a low enthalpy (heat content in a lb of air) in the outside air,
the control will open the outside air damper. When the control senses a
high enthalpy in the outside air, it will close the outside air damper. Factory
setpoint for opening the outside air damper is 75°F/40% humidity.
GC3C &
GC4
Same as above (GC3C only) plus a delay based on return air temperature.
Control delays the opening of the outside air damper to provide faster cool
down of supply air.
GA4,
GA5,
GA6,
GA7,
GA8,
GA9.
GB3
GC1A or
GC1B
Modulating
Damper
Motor with
Manual
Potentiometer
Mounted in
the Mixing
Box (GC1A)
or Remote
(GC1B)
Heating
only or
Heating
and
Cooling
To control mixture of inlet air, manually set the potentiometer to the desired
minimum position of the outside air damper. (See IMPORTANT NOTE
above.)
GC1A or
GC1B w/
GC3A
Same as above (GC1A or GC1B only) plus in heating mode the dampers
are modulated in response to a control sensing the mixed inlet air temper-
ature. Adjustable control has a range of 0-100°F; factory setpoint is 35°F.
See IMPORTANT NOTE above.
GC1A or
GC1B w/
GC4
Same as above (GC1A or GC1B only) plus a delay based on return air
temperature. Control delays the opening of the outside air damper to
provide faster cool down (cooling mode) or warm up (heating mode) of
supply air.
GC1A or
GC1B w/
both GC3A
& GC4
Includes all of the control functions listed in this section - a potentiometer
(GC1A or GC1B) with both the mixed air controller (GC3A) and the delay
(GC4).
GC3A
Modulating
Damper
Motor with
Mixed Air
Controller
Heating
only
Dampers are modulated in response to a control sensing the mixed inlet
air temperature. The adjustable control has a range of 0-100°F; factory
setpoint is 35°F. See IMPORTANT NOTE above.
GC3A &
GC4
Above plus a delay based on return air temperature. Control delays the
opening of the outside air damper to provide faster warm up of supply air.
GB4
GC3B
Modulating
Damper
Motor with a
Logic Module
and Dual
Setpoint
Modulating
Enthalpy
Control
Cooling
and
Heating
In cooling mode, damper modulation is controlled by a modulating
enthalpy control. With one sensor measuring the enthalpy of the outside
air and another sensing he return air, dampers will modulate in response
to the control to maintain the most economic mix in the inlet air (normally
set to maintain between 50-56°F). With two enthalpy setpoints, damper
operation can be interlocked with a time clock or other device to provide
different mix depending on occupancy or other determining factor. In the
heating mode, damper modulation is controlled by a mixed air temperature
sensor. (See IMPORTANT NOTE above.)
GC3B &
GC4
Above (GC3B only) plus a delay based on return air temperature. Control
delays the opening of the outside air damper to provide faster cool down
(cooling mode) or warm up (heating mode) of the supply air.
CAUA Size
2" Pleated, Disposable 2" Pleated, Aluminum
Qty Size P/N Qty Size P/N
150 - 200
2 16x16 104109 2 16x16 104103
2 16x20 104110 2 16x20 101620
250 - 400 6 16x16 104109 6 16x16 104103
IMPORTANT NOTE: The standard Model CAUA is designed for a maximum temperature rise of 75°F. Above 35°F
(2°C) outside air temperature, any percentage of outside air is permitted. For optimum operation and to prevent con-
densation, the mixed air temperature going to the heat exchanger must not be below 35°F (2°C).
This inlet air temperature restriction does not apply to a Model CAUA ordered with makeup air Option AD4. A CAUA
unit equipped with makeup air Option AD4 includes stainless steel components and a flue wrapper condensate drain
to permit inlet air temperature below 35°F (2°C).