Bryant 580F - Manual (Page 59)

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Maximum Damper Position
Set the maximum EconoMi$er+ position. Normally this is
set at 100%. If using 3-position control or there is a reason
not to use 100% outside air, this can be set using the
EconoMi$er+ Maximum Position (MAX_POS_SP).
Compressor Lockout Temperature
Set the Compressor Lockout Temperature. The Compressor
Lockout Temperature (CMP_LOCK) is used to prevent com-
pressor from running at low ambient conditions when an
EconoMi$er+ can easily satisfy the load.
EconoMi$er+ Changeover Control
Determine the type of EconoMi$er+ changeover control
which will be used to enable and disable free cooling. This is
done using the EconoMi$er+ Changeover Type.
1. Switch — This changeover setting is used when a
remote signal from an energy management system
will enable and disable the EconoMi$er+. This is
done through a remote EconoMi$er+ enable switch.
2. Outdoor Dry Bulb — For this changeover setting, the
EconoMi$er+ will be enabled based on the outdoor-air
temperature. The EconoMi$er+ is shipped with an
outdoor air temperature sensor. The outdoor air tem-
perature set point can be configured by the user. The
EconoMi$er+ will be disabled when the outdoor-air
temperature rises above the set point. The configura-
tion variable is the EconoMi$er+ Changeover set
point (OAT_SP).
3. Differential Dry Bulb — For this changeover setting,
the EconoMi$er+ will be enabled whenever the out-
side-air temperature is lower than the return-air
temperature. No configuration of set points is
required other than to select the differential dry bulb
function.
4. Outdoor Enthalpy — For this changeover setting, the
control will enable the EconoMi$er+ based on the
outdoor-air enthalpy curves as shown in Fig. 29.
Using the EconoMi$er+ Changeover set point
(ENTHALPY_SP), select curves A, B, C or D. The
control will then use the EconoMi$er+ at conditions
below the curve. The control uses the OAT and
optional humidity sensor to calculate the enthalpy
and also has the A, B, C, and D curves stored in
memory.
5. Differential Enthalpy — For this changeover setting,
the EconoMi$er+ will be enabled based on the com-
parison of the enthalpy of the return air and outside
air. If the outside air enthalpy is lower than the
return air, then the EconoMi$er+ will be enabled. To
use this option, an accessory outside air humidity
sensor, a return air dry bulb sensor and a return air
humidity sensor must be ordered and installed. No
configuration of set points is required other than to
select the function.
C. Demand Ventilation Configuration
The EconoMi$er+ control has demand ventilation control
capability when using an IAQ sensor. The indoor air quality
(IAQ) is measured using a CO
2
sensor. The IAQ sensor can
be field-installed in the return duct or the occupied space.
The EconoMi$er+ control algorithm modulates the position
of the EconoMi$er+ damper between two user configurations
depending upon the relationship between the IAQ and the
Outdoor Air Quality (OAQ). The lower of these two positions
is referred to as the Minimum IAQ Minimum EconoMi$er+
Position (IAQMIN_SP).
The higher position is referred to as the Occupied EconoMi$er+
Minimum Position (ECONOMIN_SP). The IAQMIN_SP should
be set to an EconoMi$er+ position that brings in enough fresh
air to remove contaminants and CO
2
generated by sources
other than people. The ECONOMIN_SP should be set to an
EconoMi$er+ position that brings in enough fresh air to remove
contaminants and CO
2
generated by all sources including peo-
ple at the design value for maximum occupancy.
A reference differential CO
2
level above the outside CO
2
level is used as the starting point for IAQ control and
another reference differential level for maximum ventilation
at design occupancy is used for the end of IAQ control.
Between these points the control will modulate the dampers
open from the IAQMIN_SP and the ECONOMIN_SP set-
points. The damper position will never go above
ECONOMIN_SP or below IAQMIN_SP.
The control does not measure the outdoor IAQ reference
level as these levels are relatively constant. The installer
should take a measurement at start-up of the unit and enter
this value into the control using the Outdoor Air IAQ refer-
ence level configuration.
The control is configured for air quality sensors which pro-
vide 4 mA at 0 ppm and 20 mA at 2000 ppm. If a sensor has
a different range, these bounds must be reconfigured.
To configure the control for an IAQ sensor perform the fol-
lowing steps:
1. Determine the Occupied EconoMi$er+ Minimum posi-
tion (ECONOMIN_SP) and enter it into the control.
2. Determine the IAQ minimum EconoMi$er+ position
(IAQMIN_SP) and enter it into the control.
3. Enable IAQ control using IAQ Enable (IAQ_FLG).
4. Determine the Outdoor Air IAQ Reference (OAQ) and
enter it into the control.
NOTE: The value entered into the control will be the CO
2
ppm level divided by 10. For example, 400 ppm would be
entered as 40.
5. Determine the lower control point differential level
(DAQLO) and enter it into the control. This is a dif-
ferential level so if the desired level to start IAQ con-
trol is 500 ppm and the OAQ reference level is 400
then a value of 100 would be used.
NOTE: The value entered into the control will be the CO
2
ppm level divided by 10. For example 100 ppm would be
entered as 10.
6. Determine the upper control point differential level
(DAQHI) and enter it into the control. This is a differ-
ential level so if the desired level to start IAQ control
is 1100 ppm and the OAQ reference level is 400 then
a value of 700 would be used.
NOTE: The value entered into the control will be the CO
2
ppm level divided by 10. For example 700 ppm would be
entered as 70.
D. Power Exhaust Configuration
The EconoMi$er+ can control up to 2 stages of power
exhaust. Power exhaust activation is done through config-
urable damper position set points. The first stage of power is
controlled by relay C4 on the EconoMi$er+ board. The acti-
vation point for the first stage is set using the Power
Exhaust Stage 1 Activation set point (PE_SP1). The second
stage of power exhaust must be set at a value greater than
the first stage. It is configured using the Power Exhaust
Stage 2 Activation set point (PE_SP2).