Carrier 50LC 07, Service And Maintenance Instructions, Page: 45 / 100

45
Connections and Applications
W7220 Economizer Module Wiring —
Use Fig. 54 and Tables 10 and 11 to locate the wiring
terminals for the Economizer module.
W7220 Controller
Left Terminal
Block Label
Right Terminal
Block Label
C12014
Fig. 54 -- W7220 Economizer Module Terminal Connection Labels
Table 10 – Economizer Module --
Left Hand Terminal Blocks
Label Type Description
Top Left Terminal Block
MAT
MAT
20k NTC
and
COM
Supply Air Temperature Sensor
(polarity insensitive connection)
OAT
OAT
20k NTC
and
COM
Outdoor Air Temperature Sensor
(polarity insensitive connection)
S---BUS
S---BUS
S---Bus
(Sylk Bus)
Enthalpy Control Sensor
(polarity insensitive connection)
Bottom Left Terminal Block
IAQ 2---10 2---10 Vdc Air Quality Sensor Input
(e.g. CO
2
sensor)
IAQ COM COM Air Quality Sensor Common
IAQ 24V 24 Vac Air Quality Sensor 24 Vac Source
ACT 2---10 2---10 Vdc Damper Actuator Output (2---10 Vdc)
ACT COM COM Damper Actuator Output Common
ACT 24V 24 Vac Damper Actuator 24 Vac Source
Table 11 – Economizer Module --
Right Hand Terminal Blocks
Label Type Description
Top Right Terminal Block
n/a The first terminal is not used
AUX2 I 24 Vac IN Input from Thermostat W1 indicating
base unit is in Heat mode, damper
controls to High Fan Speed
setpoints
OCC 24 Vac IN Occupied / Unoccupied Input
E---GND E---GND Earth Ground --- System Required
EXH1 24 Vac OUT Exhaust Fan 1 Output
AUX1 O 24 Vac OUT Programmable:
Exhaust fan 2 output
or
Erv
or
System Alarm output
Bottom Right Terminal Block
Y2---I 24 Vac IN Y2 in --- Cooling Stage 2 Input from
space thermostat
Y2---O 24 Vac OUT Y2 out --- Cooling Stage 2 Output to
stage 2 mechanical cooling
Y1---I 24 Vac IN Y1 in --- Cooling Stage 2 Input from
space thermostat
Y1---O 24 Vac OUT Y1 out --- Cooling Stage 2 Output to
stage 2 mechanical cooling
C COM 24 Vac Common
R 24 Vac 24 Vac Power (Hot)
Refer to Figs 55 and 56 for sensor and controls connections.