MicroScan Variable Air Volume (VAV) Controller

The MicroScan VAV is a highly accurate, compact solution for VAV applications. Designed for a single platform that combines external sensors and devices, it has the ability to set occupancy override and adjust the user set point from the zone thermostat.

Technical Specifications

Part No.

MS-VAV-AO

Physical

Dimensions: 8.87” W x 4.88” H x 2.4” D [0.225 x 0.124 x 0.609 m]
Weight: 1.42 lb [0.644 kg]

Environmental

Operating Temperature: 0°C to 50°C
Storage Temperature: -25°C to 80°C

Processor

25 MHz, 8-bit microcontroller

Memory

4 kB high-speed RAM
64 kB non-volatile FLASH EEPROM for storing code and VAV configuration settings

Supply Voltage

24VAC ±10% 60 Hz or
30–38VDC

Communications

EIA-485 Bus, MS/TP
Speeds: 1200, 9600, 19200, 38400 baud

Digital Inputs

(2) Dry-contact:

  • Occupancy override input
  • Occupancy status input

Analog Inputs

(5) 12-bit ADC:

  • Room temperature input: 500–1500 resistive input or 4–20mA loop power
  • Setpoint adjust input: 1000 resistive input maximum
  • Supply air (box discharge input): 500–1500 resistive input
  • Auxiliary input (jumper selectable): 0–5V/0–10V/4–20mA loop power
  • CFM sensor input: fully integrated on-board sensor: 0–2″ standard, optional 0–5″ or 0–1″

Digital Outputs

High-current digital output triacs @ 24VAC

  • Lights on (12VA)
  • Lights off (12VA)
  • Fan control (12VA)
  • Digital heat 1 (12VA)
  • Digital heat 2 (12VA)
  • Digital heat 3 (12VA)

Analog Outputs

  • Damper Control
  • Reheat valve control

Utilizes 12-bit DAC for excellent control resolution. 4–20mA or 0–10VDC selectable, 24VAC, 3-wire configuration

Actuator

Integrated tray actuator featuring brushless action capable of delivering up to 35 IN-lb (4 Nm), modulating action

Specifications subject to change without notice

Versatile

Pressure-independent control over a broad range of pressures and the entire operating temperature range. Compatible with all industry-standard sensors and controls, including damper actuators and valves.

  • One stage of proportional/integral heating control
  • Two types of cooling control: proportional/integral
  • Up to three stages of digital heat control: control several different terminal VAV applications with the same electronics
  • Four constant-speed fan control strategies

Easy to Install

Installation requires only a single mounting screw and the attachment to the VAV damper actuator.

Features + Benefits

  • Lightning control
  • Precise analog and integral 24VAC actuators
  • Velocity pressure sensor
  • Surface-mount integrated circuit technology
  • Flash memory
  • InfoScan system integration for VAV terminal unit control