Carrier WeatherMaster Puron 48HC D17 Service And Maintenance Instructions page 55

Fig. 70 — 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$er X system includes an economizer module,
20k mixed air sensor, damper actuator, and either a 20k out-
door air temperature sensor or S-Bus enthalpy sensors.
Economizer Module
The module is the core of the EconoMi$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 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)
2
The CO sensor can be added for Demand Controlled Ventila-
2
tion (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 48mA
IMPORTANT: All inputs and outputs must be Class 2 wiring.
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 additional
Return Air (RA) bus sensor can be added to the system for dif-
ferential enthalpy or dry bulb changeover. For differential 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 66°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 (-18°C/-17°C)
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 page 56 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
ENVIRONMENTAL
Operating Temperature
–40°F to 150°F (–40°C to 65°C).
Exception of display operation down to –4°F (–20°C) with full
2
recovery at –4°F (–20°C) from exposure to –40°F (–40°C)
Storage Temperature
–40°F to 150°F (–40°C to 65°C)
Shipping Temperature
–40°F to 150°F (–40°C to 65°C)
Relative Humidity
5% to 95% RH non-condensing
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