Economi$Er X (Factory Option) - Bryant 551K 04N Series Service And Maintenance Instructions

Economi$er X (Factory Option)

The EconoMi$er X system is an expandable economizer con-
®
trol system, which includes a W7220 economizer module (con-
troller) with an LCD and keypad (see Fig. 63). The W7220 can
be configured with optional sensors.See Fig. 64 for wiring.
Fig. 63 — W7220 Economizer Module
The W7220 economizer module can be used as a stand-alone
economizer module wired directly to a commercial set-back
space thermostat and sensors to provide outside air dry-bulb
economizer control.
The W7220 economizer module can be connected to optional
sensors for single or differential enthalpy control. The W7220
economizer module provides power and communications for
the sensors.
The W7220 economizer module automatically detects sensors
by polling to determine which sensors are present. If a sensor
loses communications after it has been detected, the W7220
economizer controller indicates a device fail error on its LCD.
SYSTEM COMPONENTS
The EconoMi$er X system includes an economizer module,
20k mixed air sensor, damper actuator, and either a 20k out-
door air temperature sensor or S-Bus enthalpy sensors.
Fig. 64 — Typical EconoMi$er X (W7220 Controller) Wiring
Economizer Module
The module is the core of the EconoMi$er X system. The mod-
ule is mounted in the unit's control box, and includes the user
interface for the system. The W7220 economizer module pro-
vides the basic inputs and outputs to provide simple economiz-
er control. When used with the optional sensors, the economiz-
er module provides more advanced economizer functionality.
S-Bus Enthalpy Control Sensors
The sensor is a combination temperature and humidity sensor
which is powered by and communicates on the S-Bus. Up to
three sensors may be configured with the W7220 economizer
module.
CO Sensor (optional)
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The sensor can be added for Demand Controlled Ventilation
(DCV).
SPECIFICATIONS
W7220 Economizer Module
The module is designed for use with 2 to 10 Vdc or bus com-
municating actuator. The module includes terminals for CO
sensor, Mixed Air sensor, and an Outdoor Dry Bulb sensor. En-
thalpy and other options are available with bus sensors.
User Interface
Provides status for normal operation, setup parameters, check-
out tests, and alarm and error conditions with a 2-line 16 char-
acter 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 48 mA
IMPORTANT: All inputs and outputs must be Class 2
wiring.
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