Zoning, Alarm detection and reporting, Sequence of operations – Orion System Modular VAV/Zone Controller User Manual

Page 26: 26 modular zcap technical guide

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Zone Polling & Voting and Alarm Detection & Reporting

Zoning

Description

The Orion system can be configured to operate as a true zoning system

with the addition of a MiniLink Polling Device. The MiniLink Polling

Device acts as a loop manager receiving information from the Modular

VAV/Zone Controller Actuator Packages, interpreting this information,

and then sending a heat, cool, or vent signal to the VCM-X Controller.

Zone Polling

The MiniLink Polling Device must be configured for zoning operation

from the Modular System Manager, System Manager TS, Modular

Service Tool, or Prism computer software. During the setup and program-

ming, the user is required to enter the last VAV/Zone address on the loop.

Once configured, the MiniLink Polling Device begins polling each VAV/

Zone Controller for its temperature and setpoint information. A zone poll

cycles through all configured zones in one pass without interruption.

The following is a list of status information required by the MiniLink

Polling Device to correctly perform its HVAC Mode calculations.

Zone Temperature

Current Cooling Setpoint

Current Heating Setpoint

Current Zone Operating Mode Status & Alarm Conditions

A zone is considered MISSING if it fails to respond to 5 consecutive

polling requests. A Missing Zone alarm can be generated in less than

2 minutes. This alarm can generate an alarm call out to maintenance

or a supervisor if the system has been properly setup. See the “Alarm

Detection And Reporting section for more information.

Zone Voting

If a zone has been configured for the VOTING mode, the MiniLink Poll-

ing Device will perform the following tests based on the data received

during the zone polling operation. These tests insure that only properly

operating zones can have an effect on the HVAC Mode calculation.

The zone has not been reported as MISSING

The zone is not currently undergoing Damper Calibration

The zone damper has not failed driving Open or Closed

and has passed Calibration

The zone temperature readings are between 40 °F and

105 ºF

The Zone Cooling Setpoint is between 55 °F and 105 ºF

The Zone Heating Setpoint is between 48 °F and 99 °F

The zone has not been declared Maverick by the MiniLink

Polling Device

The zone has been configured as a VOTING zone

If all the above tests are passed, the zone temperature and setpoints

are then included in the HVAC Mode decision; otherwise, this zone

is ignored.

Testing for Maverick Zones

During the HVAC Mode decision process, a zone cannot be included

in the Voting if it has been declared as Maverick. A zone is determined

to be a Maverick if it stays 4 ºF below the Space Heating setpoint for 1

hour or 4 ºF above the Space Cooling setpoint for 1 hour. During this 1

hour time period, the zone is still included in the voting, but it generates

a PRIORITY call for heating or cooling to the MiniLink PD. During this

1 hour time period, if the Space Temperature moves to within 2 ºF of its

Space Heating or Space Cooling Setpoint, the PRIORITY is canceled.

If the zone stays in PRIORITY for greater than 1 hour, it then becomes

a Maverick zone. At that point, its PRIORITY is canceled and the zone

is ignored in the voting process until the Space Temperature changes to

within 2 ºF of its Space Heating or Space Cooling Setpoint. If at least

75% of the zones go Maverick simultaneously, the MiniLink Polling

Device assumes an abnormal condition has occurred in the building and

resets all the zones back to normal. It then restarts the 1 hour Maverick

test over again for all zones. Maverick testing can be disabled if your

system is connected to a personal computer with the Prism Computer

Software installed.

Alarm Detection and Reporting

The VAV/Zone Controller continuously performs self diagnostics during

normal operations to determine if any operating failures have occurred.

These failures can be reported to the user in several ways, depending on

the type of system and options installed by the user. If a System Manager,

System Manager TS, or a Modular Service Tool is connected, the alarms

will be reported on the Status Screens. If the Prism computer front end

software is installed, the alarms will be reported on the main screen of

the program and be logged to disk. If the remote communications option

is installed, all alarms except the Damper Feedback Failure condition

can initiate a call out to a pager to alert someone to the alarm condition.

See the Prism Technical Guide for further information on this topic.

26

Modular ZCAP Technical Guide

Sequence of Operations

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