Internal trend logging, Force modes or overrides, Internal trend logging & force modes – Orion System Modular VAV/Zone Controller User Manual

Page 27: Sequence of operations, 27 modular zcap technical guide

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Internal Trend Logging & Force Modes

Internal Trend Logging

The VAV/Zone Controller continuously maintains an Internal Trend

Log, which records a fixed set of values at an interval programmed by

the user. These values can be retrieved only with the graphical front-end

program. In order to utilize these logs, a computer with Prism computer

software installed must be connected to the Orion system.

There are 120 log positions available. Once the last (120th) position

has been recorded, the log jumps back to the first position and begins

overwriting the old data. This means the user is required to retrieve the

logs at an interval that is shorter than the duration of the last 120 logs.

Shown below are some log intervals and the duration of 120 logs.

1 Minute Interval ............................2 Hour Duration

15 Minute Interval ..........................30 Hour Duration

30 Minute Interval ..........................60 Hour Duration

60 Minute Interval ..........................120 Hour Duration

The fixed items in the log are listed below with the column header in

parentheses:

Date (Date)

Time (Time)

Space Temperature (Space)

Active Cooling Setpoint (CoolSP)

Active Heating Setpoint (HeatSP

Supply Air Temperature (SAT)

Discharge Air Temperature (DAT)

Airflow (Airflow) [P.I. Units Only]

Damper Position (Damper)

Proportional Heat (Heat)

Current Operating Mode (Mode)

Space Temperature Mode (SPCMode)

SAT Mode (SATMode)

Fan Status (Fan)

Box Heat Stages

Auxiliary Heat Stages (Aux Ht)

Note:

For proper time and date stamping of the tenant log, you

must configure the VCM-X Controller to broadcast the

time so that the VAV/Zone Controllers can read it and

use it in their tenant and trend logs.

Caution:

These logs are subject to loss if a power outage

occurs because there is no battery-backed

memory on the VAV/Zone Controllers.

Force Modes or Overrides

The VAV/Zone Controller damper can be forced to one of several po-

sitions. These force modes aid the user during troubleshooting or air

balancing, etc.

Force Damper Full Open (Ignores Airflow Reading )

Force Damper Full Closed (Ignores Airflow Reading )

Force to Maximum Airflow/Damper Setpoint

Force to Minimum Airflow/Damper Setpoint

Force to Fixed Airflow/Damper Setpoint

Force Damper to Re-Calibrate

The Force to Fixed Airflow/Damper mode also has a setpoint associated

with it. This allows the user to provide a non-changing fixed amount

of air into the space that doesn’t affect the Minimum or Maximum set-

points. That means the user doesn’t have to disturb the real minimum

and maximum setpoints to achieve a nonstandard setting during their

troubleshooting or air balancing modes.

The Force to Minimum mode uses the currently active minimum set-

ting based on the Vent, Cooling, or Heating modes. Whatever mode

the VAV/Zone Controller is in determines the minimum used by the

force mode.

The damper force modes will remain in effect until cancelled by the user

or until the power is removed. Unlike the VCM-X Controllers which

require the initiating device to be present at all times during a force

mode, the damper force modes are more permanent since they are less

likely to damage any equipment. There are no force commands available

for the auxiliary relays.

27

Modular ZCAP Technical Guide

Sequence of Operations

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