516 01 3604 04
Specifications subject to change without notice.
27
Economi$er
®
X (Factory Option)
The EconoMi$er X system is an expandable economizer
control system, which includes a W7220 economizer mod
-
ule (controller) with an LCD and keypad (see Fig. 44). The
W7220 can be configured with optional sensors.
Fig. 44 — W7220 Economizer Module
The W7220 economizer module can be used as a stand-
alone economizer module wired directly to a commercial
set-back space thermostat and sensors to provide outside
air dry-bulb economizer control.
The W7220 economizer module can be connected to op
-
tional sensors for single or differential enthalpy control. The
W7220 economizer module provides power and communi
-
cations for the sensors.
The W7220 economizer module automatically detects sen
-
sors by polling to determine which sensors are present. If a
sensor loses communications after it has been detected,
the W7220 economizer controller indicates a device fail er
-
ror on its LCD.
SYSTEM COMPONENTS
The EconoMi$er X system includes an economizer module,
20k mixed air sensor, damper actuator, and either a 20k
outdoor air temperature sensor or S-Bus enthalpy sensors.
Economizer Module
The module is the core of the EconoMi$er X system. The
module is mounted in the unit’s control box, and includes
the user interface for the system. The W7220 economizer
module provides the basic inputs and outputs to provide
simple economizer control. When used with the optional
sensors, the economizer module provides more advanced
economizer functionality.
S-Bus Enthalpy Control Sensors
The sensor is a combination temperature and humidity sen
-
sor which is powered by and communicates on the S-Bus.
Up to three sensors may be configured with the W7220
economizer module.
CO
2
Sensor (optional)
The sensor can be added for Demand Controlled Ventila
-
tion (DCV).
SPECIFICATIONS
W7220 Economizer Module
The module is designed for use with 2 to 10 Vdc or bus
communicating actuator. The module includes terminals for
CO
2
sensor, Mixed Air sensor, and an Outdoor Dry Bulb
sensor. Enthalpy and other options are available with bus
sensors.
User Interface
The interface provides status for normal operation, setup
parameters, checkout tests, and alarm and error conditions
with a 2-line 16 character LCD display and four button
keypad.
Electrical
• Rated Voltage —
20 to 30 Vac RMS, 50/60 Hz
• Transformer — 100 va maximum system input
• Nominal Power Consumption (at 24 Vac, 60 Hz) —
11.5 VA without sensors or actuators
• Relay Digital Output Rating at 30 Vac (maximum
power from Class 2 input only) — 1.5A run:
3.5A inrush at 0.45PF (200,000 cycles) or
7.5A inrush at 0.45PF (100,000 cycles)
• External Sensors Power Output — 21 Vdc ± 5% at
48mA
INPUTS
Sensors
NOTE: A Mixed Air (MA) analog sensor is required on all
W7220 units; either an Outdoor Air (OA) sensor for dry bulb
change over or an OA bus sensor for outdoor enthalpy
change over is required in addition to the MA sensor. An ad
-
ditional Return Air (RA) bus sensor can be added to the sys
-
tem for differential enthalpy or dry bulb changeover. For dif
-
ferential dry bulb changeover a 20k ohm sensor is required
in the OA and a bus sensor in the RA. DIP switch on RA bus
sensor must be set in the RA position.
Dry Bulb Temperature (optional) and Mixed Air
(required), 20k NTC
2-wire (18 to 22 AWG)
Temperature range: –40°F to 150°F (–40°C to 65°C)
Temperature accuracy: –0°F/+2°F
Temperature and Humidity, C7400S1000 (optional)
S-Bus; 2-wire (18 to 22 AWG)
Temperature range: –40°F to 150°F (–40°C to 65°C)
Temperature accuracy –0°F/+2°F
Humidity range: 0 to 100% RH with 5% accuracy.
NOTE: Up to three (3) S-Bus sensors may be connected to
the W7220 economizer module. For outdoor air (OA), return
air (RA) and discharge (supply) air (DA).
4 Binary Inputs
1-wire 24 Vac + common GND (see Fig. 45 for wiring
details).
24 Vac power supply
20 to 30 Vac 50/60Hz; 100 VA Class 2 transformer.
OUTPUTS
Actuator Signal
2 to 10 Vdc; minimum actuator impedance is 2k ohm; bus
two-wire output for bus communicating actuators.
Exhaust fan, Y1, Y2 and AUX1 O
All Relay Outputs (at 30 Vac):
Running: 1.5A maximum
Inrush: 7.5A maximum
IMPORTANT: All inputs and outputs must be Class 2
wiring.
