York Sun Select YV28 - Page 76

Table 53: Smart Equipment
™
economizer board - SA bus details
Location Board label
Cover
label
Description Function and comments
C COM Common for SA BUS power and communication circuits
EconCtrlr parameter reports UCB-to-economizer board SA bus communication
status. Negative of the SA BUS communication circuit to the UCB. Through the
unit wiring harness, may continue on to the 4-stage board and/or fault detection
and diagnostics board
– – Communication for SA BUS devices
EconCtrlr parameter reports UCB-to-economizer board SA BUS communication
status. Positive of the VDC (typically, a fluctuating 1.5 to 3.5 V reading to C; at
least 0.25 V lower than +) SA BUS communication circuit to the UCB. Through the
unit wiring harness, may continue on to the 4-stage board and/or fault detection
and diagnostics board
1
C
1
+ + Communication for SA BUS devices
EconCtrlr parameter reports UCB-to-economizer board SA BUS communication
status. Positive of the VDC (typically, a fluctuating 1.5 to 3.5 V reading to C; at
least 0.25 V higher than –) SA BUS communication circuit to the UCB. Through
the unit wiring harness, may continue on to the 4-stage board and/or fault
detection and diagnostics board
1 When wiring the unit and other devices using the SA Bus and FC Bus, see Cable recommendations.
Table 54: Smart Equipment
™
economizer board - analog outputs
Location Board label Cover label Description Function and comments
EX VFD
2-10 VDC positive output for the modulating power
Exhaust fan Variable Frequency Drive/discharge damper
modulating power exhaust actuator
ExFanVFD parameter reports output status (0-100%) when ExFType selection is
Variable Frequency Fan; EAD-O parameter reports output status (0-100%) when
ExFType selection is Modulating Damper. Used to ramp the power exhaust fan
VFD/position the discharge damper actuator.
COM
24 VAC common/0-10 VDC negative for the power exhaust
variable frequency drive/discharge damper modulating
power exhaust actuator
Connects through circuit trace to 24V~ IN pin COM
24V~
24 VAC hot supplied for the discharge damper modulating
power exhaust actuator and economizer actuator
Connects through circuit trace to 24V~ IN pin HOT
ECON 2-10 VDC output for the Economizer actuator
Econ parameter reports output status (0-100%). Used to position the
economizer actuator for minimum position, free cooling, demand ventilation,
cooling economizer loading and purge functions
D J4
COM
24 VAC common/0-10 VDC negative for economizer
actuator
Connects through circuit trace to 24V~ IN pin COM
Table 55: Smart Equipment
™
economizer board - binary outputs
Location Board label
Cover
label
Description Function and comments
24V~
24 VAC hot supplied for an incremental (floating control)
economizer actuator
Connects through circuit trace to 24V~ IN pin HOT
ACT-A
24 VAC hot outputs to position an incremental (floating
control) economizer actuator
Unused in current control revision
ACT-B 24 VAC return Unused in current control revision
COM
24 VAC common for an incremental (floating control)
economizer actuator
Connects through circuit trace to 24V~ IN pin COM
EX-FAN
24 VAC hot output to energize power exhaust fan
contactor coil/VFD enable relay coil
ExFan parameter reports output status (Off-On) when ExFType selection is Non-
Modulating, Modulating Damper or Variable Frequency Fan. Used to turn on/
enable the power exhaust fan motor.
E J3
COM
24 VAC common/0-10 VDC negative for economizer
actuator
Connects through circuit trace to 24V~ IN pin COM
Table 56: Smart Equipment
™
economizer board - 24V~ IN connections
Location Board label
Cover
label
Description Function and comments
C COM 24 VAC transformer Common referenced to cabinet ground
24 VAC common connection to power the economizer board. Connects through
circuit traces to C/COM terminals and pins distributed on the economizer board.
F
R HOT 24 VAC transformer HOT
24 VAC hot connection to power the economizer board. Connects through circuit
traces to R/24V~ terminals and pins distributed on the economizer board.
Installation Manual: YORK
®
Sun
™
Select YV28 to YV50
76
Johnson Controls Ducted Systems