Viconics VBZS Application Guide - Manual (Page 3)

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1) System Overview and Architecture
The Viconics Zoning System product is comprised of two controller types.
• The VZ7260X5x00B Zoning controller
• The VZ7656X1000B RTU / HP controller
When combined, they deliver a simple and efficient demand based system implementation which controls
pressure dependent VAV zones with roof top units (RTU). The system is designed to work with small to
medium sized RTU staged heating and cooling equipment (2 to 20 tons).
A local BACnet RS485 MS-TP communication bus between all devices insures proper communication and
data exchange of all required information between the zones and the RTUs. They can be seamlessly
integrated into any 3
rd party BACnet supervision system.
The Viconics VZ7260X5x00B BACnet zone controller family is specifically designed for local pressure
dependent VAV zone control within Viconics zoning system product family. The primary damper output
uses a common 0 to 10 VDC VAV actuator for control.
The product features a backlit LCD display with dedicated function menu buttons for simple user operation.
Accurate temperature control is achieved due to the product’s PI proportional control algorithm, which
virtually eliminates temperature offset associated with traditional, differential-based controllers.
The zone controllers also feature a 0-10VDC sensor input that can be used for CO2 level monitoring and/or
control via the VZ7656E1000B RTU controller, or with any other 0-10VDC sensor.
The Zone controllers are also compatible with the new Viconics PIR cover accessories. Controller is
equipped with a PIR cover which provides advanced active occupancy logic. The system will automatically
switch occupancy levels from occupied to stand-by and unoccupied as required when activity is detected or
not detected by the unit. This advanced occupancy functionality provides valuable energy savings during
occupied hours without sacrificing occupant comfort. All zone controllers can be ordered with or without a
factory installed PIR cover.
The following hardware is required for operation of the zone controllers but not included:
• 24 VAC power supply. Dedicated to a single zone or many zones
• An analog 0 to 10 VDC pressure dependent actuator
• Terminal reheat if required by the design
• Proper wiring of all components as per the installation manual
• Proper network wires pulled through all devices communication connections
The Viconics VZ7656X1000B BACnet Roof Top Unit (RTU) controller has been specifically designed for
equipment control based on the zone demands..
The product also features a backlit LCD display with dedicated function menu buttons for simple operation.
Accurate temperature control is achieved through to the product’s PI proportional control algorithm, which
virtually eliminates temperature offset associated with traditional, differential-based controllers.
These controllers also contain extra digital inputs, which can be set by the user to monitor filter status or
can be used as a general purpose service indicator. Some models contain a SPST auxiliary switch, which
can be used to control lighting or disable the RTU economizer function during unoccupied periods. They
also features a discharge air sensor input. Particularly, the VZ7656E1000B features a 0-10VDC fresh air
damper output that can be used to for free cooling (economizer function) and/or for CO2 level control.
Proportional static pressure logic (input and output) has been integrated onto the controller to provide a
complete single packaged unit for most small to medium size jobs.
The following hardware is required for operation of the RTU controllers, but not included:
• 24 VAC power supply. Typically taken directly from the RTU power supply (C & RC)
• An outdoor air sensor (Viconics S2020E1000)
• A supply air duct sensor (Viconics S2000D1000)
• A return air duct sensor (Viconics S2000D1000)
• A 0 to 5 VDC static pressure sensor and transducer
• An analog 0 to 10 VDC by-pass damper actuator (spring-return or not)