AAON VCCX2 User Manual

28VCCX2 Controller Technical Guide
INPUTS AND OUTPUTS
VCC-X EM1 Expansion Module Inputs/Outputs Descriptions
Analog Inputs
T1 - Entering Water Temperature Sensor Input
The entering water is used to determine when to initiate waterside
economizer operation. If the unit is in Cooling Mode and the entering
water temperature drops 10˚F (adjustable) below the entering air
temperature, the unit modulates the waterside economizer valve as
part of the Cooling operation.
T2 - Mixed Air Temperature sensor Input
Used for direct re, requires a 10k Type III Sensor. Note the
actual sensor is an array of four sensors wired in a parallel/series
conguration to look like a single sensor.
SIG1 - Return Air Plenum Pressure Sensor Input
The sensor is only required when controlling a motorized exhaust
damper to maintain the Return Air Plenum Pressure Setpoint.
SIG2 – Economizer Damper Midway Switch
On units using Direct Fire, this is the status input of the OA damper
midway switch.
SIG3 - Economizer Feedback
If economizer operation has been congured, this input will be used
for the 2-10 VDC feedback signal from the economizer actuator.
Exhaust Duct Static Pressure Sensor Input
This jack-style input connection accepts a Duct Static Pressure
Sensor modular connector input used for exhaust duct static pressure
control. This static pressure reading is used to control the output
signal (AO4 on the VCCX2 Controller) supplied to the exhaust
fan VFD.
Binary Inputs
BI1 - Return/Exhaust Proof of Flow
A proof of ow switch that provides a wet contact closure whenever
the HVAC unit return fan or exhaust fan is operating can be
connected to this input.
BI2 – Direct Fire Status Signal
Used for direct re. A 24VAC signal from a direct re controller is
sent to indicate direct re is active.
BI3 – Direct Fire Alarm Signal
Used for direct re. A 24VAC signal is sent if there is an active
alarm on the direct re controller.
Analog Outputs
AO1 - Modulating Chilled Water Valve Actuator
This output is used to control a modulating chilled water valve
actuator to maintain the Cooling Supply Air Temperature Setpoint.
This output provides a 0-10 or 2-10 VDC direct acting signal.
AO2 - Return Air Damper Actuator Signal
This output signal is a direct acting 2-10 VDC output signal that is
used to modulate a return air damper actuator in conjunction with a
Return Air Bypass Damper actuator for AAON Precise Air Control
or Digital Precise Air Control applications.
AO3 - Return Air Bypass Damper Actuator Signal
This output signal is a direct acting 2-10 VDC output signal that
is used to modulate a Return Air Bypass Damper actuator in
conjunction with a return air damper actuator for AAON Precise
Air Control or Digital Precise Air Control applications.
AO4 - Motorized Exhaust Damper Actuator Signal
This output signal is a direct acting 2-10 VDC output signal that is
used to modulate the motorized exhaust damper actuator.
Relay Outputs
RLY1-RLY5 - User-Congurable Relays
These relays are congurable by the user. See Table 10, page 29.
12 Relay E-BUS Expansion Module
These relays are congurable by the user. See Table 10, page 29.

AAON VCCX2 Specifications

General

Brand	AAON
Model	VCCX2
Category	Controller
Language	English