8VCCX-454 Controller Technical Guide
SAFETY
Important Wiring Considerations
General
Correct wiring of the VCCX-454 Controller is the most important
factor in the overall success of the controller installation process.
In general, most VCCX-454 Controllers are installed and wired at
the AAON factory. It is also possible to purchase these controllers
through a local AAON representative for installation in the eld.
Some of the following information pertains to eld wiring and
may not apply to the installation if it was pre-wired at the factory.
However, if troubleshooting of the controller is required, it is a
good idea to be familiar with the system wiring, no matter if it was
factory or eld wired.
Controller Mounting
When the controller is to be eld mounted, it is important to mount
the controller in a location that is free from extreme high or low
temperatures, moisture, dust, and dirt. See Table 1, this page,
for a list of the required operating conditions for the VCCX-454
Controller and associated expansion modules.
The VCCX-454 Controller is housed in a plastic enclosure. It is
designed to be mounted by using the three mounting holes in the
enclosure base. The VCCX-454 Controller needs to be installed in
an environment which can maintain a temperature range between
-22°F and 158°F not to exceed 95% relative humidity levels (non-
condensing). Be careful not to damage the electronic components
when mounting the controller.
Wiring
The VCCX-454 Controller and expansion modules must be
connected to a 24 VAC power source of the proper size for the
calculated VA load requirements. All transformer sizing should be
based on the VA rating listed in Table 1, this page.
WARNING: When using a single transformer to power
multiple controllers or expansion modules,
the correct polarity must always be maintained
between the boards. Failure to observe correct
polarity will result in damage to the controller
and expansion modules.
Please carefully read and apply the following information when
wiring the VCCX-454 Controller, refrigeration modules, and
expansion modules.
• Auxiliary Power Out electrical ratings:
+VDC is 28-31 VDC at 200mA, +5V is 5 VDC at 100mA.
• All wiring is to be in accordance with local and national
electrical codes and specications.
• All 24 VAC wiring must be connected so that all ground
wires remain common. Failure to follow this procedure can
result in damage to the controller and connected devices.
• The minimum wire size for 24 VAC wiring is 18-gauge.
• The minimum wire size for all sensors is 24-gauge. Some
sensors require two-conductor wire, and some require
three-or four-conductor wire.
• The minimum wire size for 24 VAC thermostat wiring is
22-gauge.
• Be sure all wiring connections are properly inserted and
tightened into the terminal blocks. Do not allow wire
strands to stick out and touch adjoining terminals which
could potentially cause a short circuit.
• When communication wiring is to be used to connect
VCCX-454 Controllers together or to connect to other
communication devices, all wiring must be plenum-rated,
minimum 18-gauge, two-conductor, twisted pair with
shield. AAON can supply communication wire that meets
this specication and is color coded for the network or
local loop. If desired, Belden #82760 or equivalent wire
may also be used.
• Before applying power to the VCCX-454 Controller,
recheck all wiring connections and terminations thoroughly.
Powering Up
When the VCCX-454 and connected modules are rst powered up,
the POWER LED should light up and stay on continuously. If it
does not light up, verify the 24 VAC is connected to the controller,
the wiring connections are tight, and they are wired for the correct
polarity. The 24 VAC power must be connected so all ground wires
remain common. If after making all these checks, the POWER
LED does not light up, please contact AAON Controls Support
for assistance.
WIRING DETAILS
Control Device Voltage VA
Load
Temp Humidity
(Non-Condensing)
VCCX-454 Controller 18-30 VAC 15 -22°F to 158°F 0-95% RH
Evaporative Condenser, RM-454-D, RM-454-V, RM-454-Z, and
RM-454-SC
18-30 VAC 18 -22°F to 158°F 0-95% RH
EM1 Expansion Module 18-30 VAC 5 -22°F to 158°F 0-95% RH
12 Relay E-BUS Expansion Module 18-30 VAC 15 -22°F to 158°F 0-95% RH
Table 1: Voltage and Environment Requirements
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