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GENERAL W7220 CONTROLLER AND SENSOR
INFORMATION
W7220 Economizer
The economizer controller used on electromechanical units is the
Honeywell W7220 which is to be located in the RTU base unit's
control box. See Fig. 35 for button descriptions of the W7220
controller. The W7220 controller provides the following:
•
2-line LCD interface screen for setup, configuration, and
troubleshooting.
•
On-board fault detection and diagnostics
•
Sensor failure loss of communications identification
•
Automatic sensor detection
•
Capabilities for use with multiple-speed indoor fan systems
Fig. 35 — W7220 Controller
User Interface
The user interface consists of a LCD display and a 4-button
keypad on the front of the economizer controller.
Keypad
The four navigation buttons (see Fig. 35) are used to scroll
through the menus and menu items, select menu items, and
change parameter and configuration settings.
Using the Keypad with Menus
To use the keypad when working with menus:
•
Press ▲ (Up arrow) button to move to the previous menu.
•
Press the ▼ (Down arrow) button to move to the next menu.
•
Press the
(Enter) button to display the first item in the
currently displayed menu.
•
Press the
(Menu Up/Exit) button to exit a menu's item
and return to the list of menus.
Using the Keypad with Settings and Parameters
To use the keypad when working with Setpoints, System Setup
Advanced Settings, Checkout Tests and Alarms:
1.
Navigate to the desire menu.
2.
Press the
(Enter) button to display the first item in the
currently displayed menu.
3.
Use the ▲ and ▼ buttons to scroll to the desired parameter.
4.
Press the
(Enter) button to display the value of the
currently displayed item.
5.
Press the ▲ button to increase (change) the displayed
parameter value.
6.
Press the ▼ button to decrease (change) the displayed
parameter value.
NOTE: When values are displayed, pressing and holding the ▲ or
▼ button causes the display to automatically increment.
7.
Press the
(Enter) button to accept the displayed value and
store it in nonvolatile RAM (Random Access Memory).
8.
"CHANGE STORED" displays.
9.
Press the
(Enter) button to return to the current menu
parameter.
10. Press the
(Menu Up/Exit) button to return to the previous
menu.
Menu Structure
Refer to Table 10 for summarized standard settings. Table 11
illustrates the complete hierarchy of menus and parameters for the
EconoMi$er X system.
The menus in display order are:
•
STATUS
•
SETPOINTS
•
SYSTEM SETUP
•
ADVANCED SETUP
•
CHECKOUT
•
ALARMS
IMPORTANT: The default setting on the W7220 controller is
for a Fan Type" with 2 speed. For a 1 (single) speed unit, the
setting under SYSTEM SETUP > FAN TYPE must be changed
to 1 speed.
PROGRAMMING W7220 CONTROLLER
The next several pages detail the different status displays, set-
points, setup, and alarms available on the controller. This list
below and Table 10 summarizes the inputs required for a standard
application with a single outside air sensor.
NOTE: Default settings already set in the controller may be used
instead of setting the SETPOINTS; see default settings below. See
Table 10 for summarized standard settings or for more detail see
Table 11.
Setpoints
•
MAT SET: this sets the mixed air temperature (MAT)
setting. The controller has a default of 53°F, but the range
is anywhere from 38°F to 70°F.
•
LOW T LOCK: This setting locks out the compressor (or
mechanical cooling) at a given temperature. The default is
32°F, but the controller's range is from –45°F to 80°F.
•
DRYBULB SET: for an economizer with a dry bulb
outside air sensor, set the DRYBULB SET. The default
setting is 63°F but the controller's range is 48°F to 80°F.
•
ENTH CURVE: for a single enthalpy outside air sensor
instead of a dry bulb, set the ENTH CURVE setting. There
are 5 setting options: ES1 through ES5. Check the
economizer literature for the limits for each of these
settings. ES3 is the default setting.
•
MIN POS: The minimum position allows for ventilation
even when not in the free-cooling mode. A single speed unit
has only one minimum position setting. The default is 4.4
volts, but the range is 2-10Vdc.
•
MIN POS H and MIN POS L: A 2 speed unit has 2
minimum position settings that show up on the menu. The
first is MIN POS H (for high speed) which has a default of
4.4 volts. The second is MIN POS L (for low speed), which
has a default of 6.0. Note that MIN POS H and MIN POS L
are only displayed if under SYSTEM SETUP: AUX2 IN is
set to "W1" and FAN TYPE is set to 2 speed.
16
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