General; Sensor/Accessory Installation - Carrier 48LCB07 Controls, Start-Up, Operation And Troubleshooting

GENERAL

The VAV-RTU Open controller (see Fig. 2) is an integrated com-
ponent of the Variable Air Volume (VAV) Carrier rooftop unit sys-
tem (see Fig. 1). Its internal application programming provides
optimum performance and energy efficiency. VAV-RTU Open en-
ables the unit to operate with Carrier's i-Vu Open network with i-
Vu VAV zone controllers (Fig. 3 and 4) and monitored by Third
Party BACnet Building Automation System (BAS). VAV-RTU
1
Open operates as part of an Open Air Terminal system using Car-
rier Airside Linkage or as a Standalone air source using BACnet to
communicate with a third party system which is available with the
version 2 or later release. On-board DIP switches allow you to se-
lect your baud rate. (See Fig. 2.) Carrier's i-Vu user interface
Equipment Touch or System Touch and the Field Assistant techni-
cian tool can be used with the VAV-RTU Open controller. Access
is available via a 5-pin J12 access port or Rnet communication
network. Carrier's System Touch interface can be used to config-
ure the VAV rooftop and air terminal controllers when connected
to the BACnet MS/TP network.

SENSOR/ACCESSORY INSTALLATION

There are a variety of sensors and accessories available for the
VAV-RTU Open and VAV zones. Some of these can be factory or
field installed, while others are only field installable. The VAV-
RTU Open controller requires connection to the building zoning
1. BACnet is a registered trademark of ASHRAE (American Society of Heat-
ing, Refrigerating, and Air-Conditioning Engineers).
BACnet MS/TP
(RS-485)
Zone
Controller
Zone sensor Zone sensor
Zone
Controller
Zone sensor
Fig. 1 — Typical VAV-RTU Open System
VAV system. All field control wiring that connects to the VAV-
RTU Open must be routed through the raceway built into the cor-
ner post of the unit or secured to the unit control box with electri-
cal conduit. The unit raceway provides the UL required clearance
between high and low-voltage wiring. Pass the control wires
through the hole provided in the corner post, then feed the wires
thorough the raceway to the VAV-RTU Open. Connect the wires to
the removable Phoenix connectors and then reconnect the connec-
tors to the board. See Fig. 2 and Table 1 for board connections and
Fig. 5 - 10 for Typical Factory VAV-RTU Open wiring.
IMPORTANT: Refer to the specific sensor or accessory
instructions for its proper installation and for rooftop unit
installation refer to base unit installation instructions and the
unit's wiring diagrams.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death and/or equipment damage.
Disconnect electrical power and use lock-out tags before
wiring the VAV-RTU Open controller.
Zone
Controller
Zone
Controller
Zone sensor
3
WARNING
Factory Installed
VAV-RTU Open Controller
PROT485
Surge
Protector