36
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
2
Sensor (optional)
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 communi-
cating 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
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 additional Re-
turn Air (RA) bus sensor can be added to the system for differen-
tial enthalpy or dry bulb changeover. For differential dry bulb
changeover a 20k ohm sensor is required in the OA and a bus sen-
sor 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 (0°C/+1°C)
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 page 37 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
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
ECONOMIZER MODULE WIRING DETAILS
Use Fig. 48 and Tables 15 and 16 to locate the wiring terminals for
the Economizer module.
NOTE: The four terminal blocks are removable. Slide out each
terminal block, wire it, and then slide it back into place.
Fig. 48 — W7220 Wiring Terminals
IMPORTANT: All inputs and outputs must be Class 2 wiring.
NA
AUX2-
OCC
E-GND
EXH1
AUX1-O
Y2-
Y1-
Y2-O
Y1-O
C
R
50048848-002
Rev. A
NA
A2
OCC
EX
A1
Y2I
Y2O
Y1I
Y1O
C
R
MAT
MAT
OAT
OAT
S-BUS
S-BUS
IAQ 2-10
IAQCOM
IAQ 24V
ACT 2-10
ACT COM
ACT 24V
MA
MA
OA
OA
SB
SB
SB
SB
SB
SB
V
C
R
V
C
R
NA
50040839-001
Rev. G
HJW10
www.energy.ca.gov
Certified FDD Product
California Title 24, Part 6
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