Viconics VZ7260 5 00B Series Application Manual Download Page 1

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Viconics BACnet Zoning System

Application Guide

VZ7260X5x00B and VZ7656X5000B Controllers

VBZS_Rel2_Application_Guide-E04

(R1 Issue Date: January 10

, 2012)

Summary of Contents for VZ7260 5 00B Series

Page 1: ...1 Viconics BACnet Zoning System Application Guide VZ7260X5x00B and VZ7656X5000B Controllers VBZS_Rel2_Application_Guide E04 R1 Issue Date January 10th 2012 ...

Page 2: ...nd cooling system B Overrides and user zone interface lockouts C Zone set point limits D Heating and cooling weight zone selection E Minimum maximum and max heat flow adjustments F Terminal reheat lockout G Passive infra red motion detector cover PIR H AI4 CO2 Other Sensor Input Operation I Disable Minimum Position parameter J Heating and Cooling Performances 3 RTU controllers VZ7656X1000B operati...

Page 3: ...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 ...

Page 4: ...2 x Tri state floating 1 x Auxiliary reheat contact PIR Cover PIR cover ready PIR cover factory installed PIR cover ready PIR cover factory installed Master Controllers Available Models Features Viconics Part Number VZ7656R1000B VZ7656H1000B VZ7656F1000B VZ7656E1000B Controlled Equipment Rooftop Unit Heat Pump Unit Rooftop Unit Rooftop Unit Main Control Outputs 2H 2C 3H 2C 0 10VDC Analog Heat 2C 2...

Page 5: ...Z72xx Product Guide Installation and commissioning information is available on document LIT VZ7260X_B Exx For detailed information on the Viconics VZ76xx RTU controller please refer and read the VZ76 Product Guide Installation and commissioning information is available on document LIT VZ7656X_B Exx PIR cover installation information is available on document PIR Cover Installation Exx Information o...

Page 6: ...If the equipment is undersized for the required peak loads the control system will distribute the available capacity according to the priorities requested hence making most of the areas comfortable Proper planning and design will ensure that a job site will be up and running faster with less service calls during the initial occupancy period 1B Scalability and Limitations The system is fully scalab...

Page 7: ...fficient with air delivery close to the outside walls In certain problematic cases where air delivery may be an issue the use of fan powered VAV units may reduce the occupant discomfort by providing constant airflow to the zone and maximizing the air delivery process 1 D Special Considerations A typical office installation may require that a single unit service areas being used for different appli...

Page 8: ...rollers VZ7260X5x00B Operation The following information needs to be carefully read and properly understood if proper system commissioning is to be achieved Contrary to low end commercial and residential zoning controllers which use a two positions open close actuator Viconics VZ7260X5x00B uses proportional analog 0 to 10 VDC modulating damper actuator This enables performances and control sequenc...

Page 9: ...emand Current heat demand Current heat demand Highest Average of 3 highest 50 0 0 Heat weight set Heat weight set Heat weight set 50 100 100 Resulting heat weight to RTU Resulting heat weight to RTU Resulting heat weight to RTU 25 0 0 25 8 3 Current cool demand Current cool demand Current cool demand 0 100 100 Cool weight set Cool weight set Cool weight set 100 100 50 Resulting cool weight to RTU ...

Page 10: ...r for the five master voting zones are different and will result in different heating action simply based on the RTU configuration Please note that the heating or cooling action delivered to the zones is also dependent on heating and cooling lockout functions based on the outdoor and supply air temperature Please see the next section for more information 2B Overrides and User Zone Interface Lockou...

Page 11: ...be in unoccupied mode and using their unoccupied set points Pressing local keys that have their function locked out will display a keypad lock message on the zone controller display If a global override is required for the whole system and all zones return to occupied mode then the override needs to be enabled at the RTU controller itself This can be accomplished by using the local user menu at th...

Page 12: ...nded Settings Heat max Maximum local heating set point limit Default 90 F 32 C 75 F 24 C Cool min Minimum local cooling set point limit Default 54 F 12 C 68 F 20 C 2D Heating and Cooling Weight Zone Selection For any system to operate properly care must be taken to select which zones will be driving the system as well as their weight attached to the calculations The values below are provided as an...

Page 13: ...ossible for an internal zone to be slightly overheated during peak winter heating loads because of the dampers minimum position During occupied periods the RTU is providing its maximum heating capacity and the amount of hot air provided by the dampers minimum position will provide more heat to the internal zone than necessary o External zones considered of primary importance should have both their...

Page 14: ... set to any value except None None No local reheat An example of this is a local reheat configuration using a duct mounted reheat coil device Type of reheat configured RehtConf BO5 reheat output time base BO5 Time MaxHTPos value function and adjustment 0 None N A Leave default of 30 or any adjustment MaxHTPos is not used in scenario 1 Analog Duct Rht Only N A Set to any value superior to the curre...

Page 15: ... configuration parameter to the desired value as required by balancing Balancing Maximum Air Flow 1 Be sure local system heating is allowed by setting the outdoor heating lockout value at the RTU controller H Lock 2 Be sure the system is currently in heating mode As viewed locally at the RTU controller by pressing the manual scroll button and displaying the local Zone Sequence Heat message prompt ...

Page 16: ...ow Oversized VAV Undersized VAV Effective Control Area Effective Control Area Be sure the VAV actuator is properly installed and set up so the VAV damper blade is able to rotate from the fully opened to fully closed position with no restriction to its mechanical rotation 2F Terminal Reheat Lockout It is possible to lockout out the local terminal reheat function of the zones during hot seasons or w...

Page 17: ...or the system to recover quickly and be within the occupants comfort zone in as short a time as possible If the span Delta Temperature from occupied to stand by setpoints is too large the zone will not be able to recover quickly and the occupants will be left uncomfortable for the duration of the occupied periods initiated by the PIR In order for the PIR logic function to be enabled the following ...

Page 18: ... for control purposes the AI4 parameter should be then set to CO2 In this case a CO2 value will be displayed at the end of the configuration parameters list showing the CO2 level measured by the sensor in ppm particles per minute The value of the AI4 input will also be displayed at the network level under Room CO2 Value BACnet object in ppm AI4 value BACnet object in VDC When AI4 parameter is conf...

Page 19: ...the zone demand are different here s the table showing when this parameter is effective Zone Sequence Zone Demand DisMinPo effectiveness Damper Position Cool Cool Effective Minimum Position Cool Heat Not Effective Closed Cool No Demand Effective Minimum Position Heat Cool Effective Minimum Position Heat Heat Not Effective Closed Heat No Demand Effective Minimum Position 2 J Heating and Cooling Per...

Page 20: ... output value is based on PI cooling weight configuration Each voting controller will also calculate its demand values based on the current occupancy mode and set points in use Unoccupied Stand By or Occupied Based on the control type function setting CntrlTyp the RTU controller will calculate the resulting heating and cooling zone demands See section 2A Demand Based Heating and Cooling System Pro...

Page 21: ...prevent unwanted inputs to the system as a whole when the RTU controllers are installed in public areas or when certain local user interface functions of the RTU controllers are to be prevented Lock level is access through the Lockout configuration parameter Please set the appropriate level for each individual zone in the system according to their requirements VZ76 Controller Lockout Level Configu...

Page 22: ...tside Air Temperature It is also possible to set the system to completely eliminate heating and cooling equipment cycling based on outdoor air limitations if this type of operation is required This of will have an impact on specific zone performances 3F Critical Mid Season Changeover Heating and cooling RTU equipment cycling during mid seasons is inevitable with a zoning VAV system if any degree o...

Page 23: ...ability of the set point is 0 to 2 in WC 0 Pa to 500 Pa increments 0 1 WC or 25 Pa Please note that the static pressure scale will automatically change from inches of WC to PA Pascals when the local units configuration parameter is changed 0 SI for Celsius Pa pressure scale 1 Imp for Fahrenheit in WC pressure scale Operation of the static pressure control loop is dependent on the fan running or no...

Page 24: ...from dropping below the Min SH Minimum Supply Heat Temperature parameter value This control sequence is only available in the VZ7656F1000B modulating heat rooftop controller An outdoor temperature supply air lockout is also one of the VZ7656F1000B features This lockout only affects the minimum supply heat control sequence Room temperature control is not affected The SH Lock is the parameter used t...

Page 25: ...ive The FA Range parameter should be set to 0 CFM Default Value 0 CFM Set the Chngstpt parameter to desired value which free cooling is enabled Default Value 55 F If the outside air temperature is greater than the changeover setpoint then normal mechanical cooling will be used If the outside air temperature is less than or equal to the changeover setpoint then free cooling will be enabled and mech...

Page 26: ...e FA Range parameter should be set to a value higher than 0 CFM 0 CFM disables the fresh air control Min FA minimum fresh air parameter should be set to the desired level The FA Range parameter value should be set to the maximum capacity of the fresh air measurement station Therefore the relationship between air volumes and input signals can be established For example if the fresh air station capa...

Page 27: ...l as the free cooling sequence will be active The FA Range parameter should be set to 0 CFM Set AI4 parameter to CO2 0 VDC 0ppm 10VDC 2000ppm Min Pos Max Pos Min CO2 and Max CO2 parameters should be set according to the required setting Min Pos Max Pos Min CO2 Max CO2 Current Fresh Air Damper Position Current CO2 Level The higher value between free cooling output and interpolation output between t...

Page 28: ...ould be set to something other than 0 CFM Use an air flow transmitter to read fresh air level with AI2 input 0 5 VDC input Min FA Max FA Min CO2 and Max CO2 parameters should be set according to the required setting Min FA Setpoint Max FA Setpoint Min CO2 Max CO2 Current Fresh Air Setpoint Current CO2 Level The higher value between free cooling output and interpolation output based on the above gr...

Page 29: ...e current master and will answer or acknowledge any request from the current master When the current controller is done with the token it will pass it to the next controller in the network and so on Baud Rate All controllers in the network need to communicate at the same speed in order to properly exchange information The speed rate is called baud rate Each individual controller can be assigned a ...

Page 30: ...sy chain configuration Figure 3 Three different network configurations star bus and daisy chain Only the daisy chain configuration is correct for an EIA 485 network A daisy chain wiring scheme does not allow for T connections I E the network wire needs to be wired down to each controller communication terminals before going to the next device No junctions of any kind are recommended to be installe...

Page 31: ... represent the lowest and highest MAC addresses given to the controllers Shield The purpose of the shield is to protect the communication network from external radio noise sources DO NOT WIRE THE SHIELD s TO THE Ref COMMUNICATION TERMINAL The shield for the first and the last devices located behind the controller must be fully protected to prevent accidental shorting to the ground The shields for ...

Page 32: ... Commissioning It cannot be stressed enough that if proper system operation is expected then proper system commissioning should be done at all levels A zoning system has a huge dependency on demand and response being fully functional both at the RTU and the zone level 5A Proper Commissioning of Zone Controllers At the zone level care should be applied to insure the following have been properly set...

Page 33: ...O operation including the RTU on board economizer operation 5C Operational System Checklist It is recommended to keep a checklist of all milestones and configuration settings during start up This list should be kept as a reference with the system when it is fully commissioned The following is only provided as a guideline template but can be extremely helpful for servicing issues and questions RTU ...

Page 34: ...e Pressure Communication with zones is active Status LED manual scroll display Local time clock set Local schedule set Local system mode set to Auto System On Outdoor air sensor properly connected and displaying value manual scroll display Supply air sensor properly connected and displaying value manual scroll display Return air sensor properly connected and displaying value manual scroll display ...

Page 35: ...ny zone controllers If using a single 24 VAC for each zone controller Use a 20 VA or more Class2 self protected transformer to power all components attached to the zone controller Be sure to respect the polarity of all components in the circuit analog VAV actuator analog reheat etc Be sure that if a ground is required the common side of the circuit is the one connected to earth 0 V Com Grounding i...

Page 36: ...g are mandatory 6C Balancing and Capacity It is not the mandate of a zoning control system to correct for an incorrect mechanical layout or for improper load calculations of the mechanical zoning equipment The control system will deliver the loads required by the master demanding zones by appropriately distributing the total available capacity of the installed equipment to the required demanding z...

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