VCB-X Controller Field Technical Guide
INSTALLATION & WIRING
19
WARNING:
When using a single transformer to power more
than one controller or expansion module, the
correct polarity must always be maintained be-
tween the boards. Failure to observe correct
polarity will result in damage to the VCB-X
Controller and expansion modules.
Please carefully read and apply the following information when
wiring the VCB-X Controller or the Expansion Modules. See
Figures
6 & 7
for VCB-X input and output wiring. See
Figures 22 & 23
for
the VCB-X EM1 Expansion Module wiring,
Figures 34 & 35
for
VCB-X EM2 Expansion wiring, and
Figure 36
for the VCB-X 12
Relay Expansion Module wiring.
1. All wiring is to be in accordance with local and national
electrical codes and speci
fi
cations.
2. 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.
3. Minimum wire size for 24 VAC wiring should be
18-gauge.
4. Minimum wire size for all sensors should be 24-gauge.
Some sensors require 2-conductor wire and some require
3-or 4-conductor wire.
5. Minimum wire size for 24 VAC thermostat wiring
should be 22 gauge.
6. Be sure that 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.
7. When communication wiring is to be used to intercon-
nect VCB-X Controllers together or to connect to other
communication devices, all wiring must be plenum-
rated, minimum 18-gauge, 2-conductor, twisted pair with
shield. WattMaster can supply communication wire that
meets this speci
fi
cation and is color coded for the
network or local loop. Please consult your WattMaster
distributor for information. If desired, Belden #82760 or
equivalent wire may also be used.
8. Before applying power to the VCB-X Controller,
be sure to recheck all wiring connections and
terminations
thoroughly.
Important Wiring Considerations
General
Correct wiring of the VCB-X Controller is the most important
factor in the overall success of the controller installation process. In
general, most VCB-X Controllers are factory installed and wired at
the AAON
®
factory. It is also possible to purchase these controllers
through your local AAON
®
/Orion representative for installation in
the
fi
eld. Some of the following information pertains to
fi
eld wiring
and may not apply to your 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
fi
eld wired.
Controller Mounting
When the controller is to be
fi
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
for a list of
the required operating conditions for the VCB-X Controller and
associated expansion modules.
The VCB-X Controller is housed in a plastic enclosure. It is designed
to be mounted by using the 3 mounting holes in the enclosure base.
The VCB-X Controller needs to be installed in an environment
which can maintain a temperature range between -30°F and 150°F
not to exceed 90% RH levels (non-condensing). Be careful not to
damage the electronic components when mounting the controller.
Considerations
The VCB-X 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
.
Contr
ol
De
vice
V
olta
ge
V
A
Load
Temper
atur
e
Humidity
(Non-
Condensing)
OE335-26B-VCB-X-A
VCB-X Controller
24VAC
8
-30°F to
150°F
90% RH
OE336-23-EM1-A
24VAC
5
-30°F to
150°F
90% RH
OE336-23-EM2-A
24VAC
5
-30°F to
150°F
90% RH
OE358-23E-12R-A
24VAC
15
-30°F to
150°F
90% RH
Table 1: Voltage and Environment Requirements
