Indoor Air Quality Aq; Gas Heating Operation - York International ZQ Series Installation Manual

Table 58: Smart Equipment™ Economizer Board Details
Board Label Cover Label
IN8
BLDG PRES
C
COM
PURGE
IN9
24V~
EX VFD FLT
IN10
24V~
1 When wiring unit and other devices using the SA Bus and FC Bus, see Table "Cable for FC Buses and SA Buses in Order of
Preference".

Indoor Air Quality AQ

Indoor Air Quality (indoor sensor input): Terminal
AQ accepts a +2 to +10 VDC signal with respect to
the (AQ1) terminal. When the signal is below it's set
point, the actuator is allowed to modulate normally
in accordance with the enthalpy and mixed air
sensor inputs. When the AQ signal exceeds it's set
point setting and there is no call for free cooling, the
actuator is proportionately modulated from the 2
to 10 VDC signal, with 2 VDC corresponding to full
closed and 10 VDC corresponding to full open. When
there is no call for free cooling, the damper position
is limited by the IAQ Max damper position setting.
When the signal exceeds it's set point (Demand
Control Ventilation Set Point) setting and there is a
call for free cooling, the actuator modulates from
the minimum position to the full open position
based on the highest call from either the mixed air
sensor input or the AQ voltage input.
Optional CO Space Sensor Kit Part #
•
2
2AQ04700524B
Optional CO Sensor Kit Part # 2AQ04700624C
•
2
70 INSTALLATION MANUAL ZQ SERIES 3 - 5 ton 60 Hertz R-410A
Description
0-5 VDC positive input from the Building Pressure sensor
24 VAC common/0-5 VDC negative for the building
pressure sensor
BINARY INPUTS at right on lower edge of economizer board
24 VAC hot input from the PURGE dry contact
24 VAC hot supplied for the purge dry contact
24 VAC hot input from the power Exhaust Variable
Frequency Drive Fault contact
24 VAC hot supplied for the power exhaust variable
frequency drive fault contact
Johnson Controls Ducted Systems
Function and Comments
BldgPres parameter reports input status (-.250-.250"/w/-.062-.062kPa). Used
for modulating power exhaust functions when ExFType selection is Modulating
Damper or Variable Frequency Fan.
Connects through circuit trace to 24V~ IN pin COM
Purge parameter reports input status (False with 0 VAC input-True with 24 VAC
input). When Purge status is True, heating and cooling operation is prevented,
the indoor blower and power exhaust fan operate, the economizer actuator is
positioned to 100%.
Connects through circuit trace to 24V~ IN pin HOT
ExFanVFDFlt parameter reports input status (Normal with 0 VAC input-Alarm
with 24 VAC input) when ExFType selection is Variable Frequency Fan. When
ExFanVFDFlt status is Alarm, EX-FAN fan output is prevented.
Connects through circuit trace to 24V~ IN pin HOT
Figure 28: Ignition Control Board

Gas Heating Operation

1. Heating stages are controlled by the W1
through W2 thermostat inputs. A W1 or W2
input energizes a H1 or H1/H2 output.
2. When the pre-ignition process is complete the
ignition module energizes the gas valve and
provides a 24 V input to the MV terminal on
the UCB.
3. The FAN ON HEAT DELAY timer starts as soon
as 24 V is present on MV terminal. When the
timer expires the FAN output for the indoor
fan operation energizes. If 24 V is not received
on the MV terminal within 6 minutes, an
alarm appears and the fan output energizes
immediately and remains On until the alarm
clears.