Orion System VCM Controller - Manual (Page 4)

Technical Guide
VCM Controller 4
Features
The VCM Controller Board is designed with 7 analog inputs, 2 analog
outputs and 5 relay outputs. The controllers input and output capabili-
ties can be expanded by use of either 2 slot or 4 slot expansion boards
that plug into the VCM Controller by means of a modular cable. The
VCM Controller can be configured for control of VAV Units (with or
without VAV/Zone Controllers), Constant Volume Units and Make-up
Air Units. Features include the following:
• Up to a Combined Total of 20 Stages of Heating & Cooling
• Modulating Cooling Output (Digital Compressor or Chilled
Water Valve Control)
• Modulating Heating Output (Hot Water Valve, Steam Valve,
SCR Electric Heat Control)
•
Full Integration with the AAON ®
MODGAS II Modulating Natural Gas Controller
•
Full Integration with the AAON ® MHGRV II Modulating
Hot Gas Reheat Controller
• Configurable for Air to Air Heat Pump Applications
• Advanced Dehumidification Capabilities
•
Primary/Secondary Heating Control
• Automatic Supply Air Reset
• Selectable Control Sensor
• Fan Proving Interlock
• Dirty Filter Alarm
•
Smoke Detector Input
•
Drybulb/Wetbulb Control of Economizer Operation
• Building Pressure Control
• Remote Override Capabilities
• I.A.Q. Economizer Reset
• 7 Day, 2 Event per Day Scheduling
• 14 Holiday Event Scheduling
• Optimal Start Scheduling
• Trend Logging Capability
• Static Pressure Control For Filter Loading Applications
•
Accepts Remote HVAC Mode Selection Via Contact
Closure On Expansion Input Board
• Configurable for PAC and DPAC Applications
Controller Overview
Most common HVAC unit control applications can be configured using
only the VCM Controller board. If the application requires more inputs
and/or outputs, optional expansion boards are available to provide for
additional analog, binary or digital inputs and outputs as required. These
expansion boards are installed on either a 2 slot or 4 slot expansion base
board that connects to the VCM Controller board via a modular cable
connection.
The available expansion board configurations allow for (8) additional
binary inputs, 4 additional analog inputs, 1 additional analog output,
and up to 16 additional binary (relay) outputs. The various expansion
boards connect to the 2 slot or 4 slot expansion base boards. Jumpers
located on the base boards near each expansion board socket must be
set according to the board type installed on that socket.
Applications
Variable Air Volume Unit
The VCM can be configured to control a VFD Supply Fan for Duct
Static Pressure control. If the unit is not equipped with a VFD, but Duct
Static Pressure control is needed, a modulating Zoning Bypass Damper
can be controlled by the VCM.
VAV units are typically designed for occupied Cooling with Morning
Warm-up Heating. This option is available with the VCM. The VCM
can also be used for a Zoning System that needs Duct Static Pressure
control and Occupied Cooling and Heating. The VCM also has the abil-
ity to be configured for Duct Static Pressure Control by controlling the
Supply Fan VFD for the purpose of maintaining proper Duct Static
Pressure in response to varying filter loading conditions.
The VCM allows Dehumidification Priority on a VAV unit. This could
be useful on a building with very low internal sensible load, but has a
high internal and/or external latent load. During VAV Dehumidification
the VCM activates Cooling based on the Evaporator Coil Temperature
and activates Modulating Hot Gas Reheat to warm the Supply Air Tem-
perature to the Active Supply Air Temperature Setpoint.
Constant Air Volume Unit
The VCM can be configured to activate a Constant Volume Supply
Fan. In most cases, this is a very basic unit with Space Temperature
control. The VCM can be used for kitchen, restaurant or lab environ-
ments that are 100% Outdoor Air part of the time and return air part of
the time. The Hood On input allows the VCM to know when to switch
to 100% Outdoor Air control based on an exhaust hood activating. The
VCM requires Outdoor and Indoor Air Temperature Sensors to accom-
plish this application.
Make-up Air Unit
The VCM can be configured for 100% Outdoor Air control for Make-
up Air. All HVAC Modes are determined from the Outdoor Air Sensors.
The Outdoor Air Volume must always be at least 50% or higher to be
configured for Outdoor Air control.