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VCCX2 Controller Technical Guide
R1 - Supply Fan (Enable)
This is a non-configurable output.
R2-R8 - User-Configurable Relays
These relays are configurable by the user. For all the available
configuration options, see
Table 4, page 69
.
VCC-X EM1 Expansion Module
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 (adj.) below the
Entering Air Temperature, the unit will begin to modulate the
Waterside Economizer Valve as part of the cooling operation.
See Waterside Economizer (
page 87
) for a full description of
this operation.
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.
SIG3 - Economizer Feedback
If Title 24 Economizer operation has been configured, 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.
BIN 1 - Return/Exhaust Proof of Flow
A Proof of Flow Switch that provides a wet contact closure
whenever the HVAC unit Return Fan or Exhaust Fan is operating
can be connected to this input.
AOUT1 - 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.
AOUT2 - 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 (PAC) or Digital Precise Air Control (D-PAC)
applications.
AOUT3 - 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 (PAC) or Digital Precise Air Control (D-PAC)
applications.
AOUT4 - 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.
R1-R5 - User-Configurable Relays
These relays are configurable by the user. For all the available
configuration options, see
Table 4, page 69.
12 Relay E-BUS Expansion Module
Please refer to the user-configurable relays in
Table 4, page 69
for relay definitions.
NOTE:
For Reverse Acting Building Pressure Control
using the Outdoor Air Damper or Supply Fan
VFD, the VCCX2 Controller will use the outputs
specific to those devices. On the main VCCX2
Controller, AO2 would control the Outdoor Air
Damper and AO1 would control the Supply Fan
VFD to maintain the Building Pressure Setpoint.
Alternatively, this AO4 output will mirror those
outputs and can be used as well.
INPUTS AND OUTPUTS
VCC-X EM1 Expansion Module
