WattMaster WM-WCC3-TGD-01B - Manual (Page 771)

3
VAV/Zone Controller Technical Guide
Operator Interface
Features
VAV/Zone Controller
This manual applies to the VAV/Zone Controller that is included in the
following WCC III products:
OE742-XX-VAVZ VAV/Zone Package
Pressure Dependent
OE744-XX-VAVZ VAV/Zone Package
Pressure Independent
OE520-XX VAV/Zone Round Damper
Assembly - Pressure Dependent
OE521-XX VAV/Zone Round Damper
Assembly - Pressure Independent
OE736-XX VAV/Zone Rectangular Damper Kit
The VAV/Zone Controller is used for controlling airfl ow and operation
of VAV or Zoning terminal units. It is a programmable digital controller
which allows for program setpoints to be stored in non-volatile memory.
The controller is connected to a room sensor via a 2- or 3-wire cable
assembly which monitors space temperature allowing the VAV/Zone
Controller to modulate a damper in response to space temperature, duct
temperature, and airfl ow requirements in the controlled space.
The VAV/Zone Controller has three integral modular jacks for con-
nection to the actuator, airfl ow sensor (for pressure independent ap-
plications), and relay/analog Expansion Board via modular cables.
Terminal connections are provided for the 24 VDC power and system
communications. The controller has an on-board dip switch provided
for board addressing.
Controller Overview
The VAV/Zone Controller is provided with two relays for tri-state control
of the damper actuator. All outputs and the relay common are electri-
cally isolated from all other circuitry on the board. All relay outputs are
supplied with transient suppression devices across each set of contacts
to reduce EMI and arcing. The relay output contacts are rated for pilot
duty control of a maximum of 2 Amps @ 24 VAC or 24 VDC. The
actuator connects via a modular cable to the board and provides the
VAV/Zone Controller with feedback monitoring for precise positioning
of the actuator.
OE322 Output Expansion Boards
The OE322, 3 Relay with Analog Output Expansion Board is used in
conjunction with the VAV/Zone Controller board to allow for control of
VAV and Zone terminal units, including series and parallel fan terminal
units with up to 3 stages of electric heat or modulating hot water heat.
The OE322, 3 Relay with Analog Output Expansion Board provides 3
relay outputs for pilot duty switching control, and 1 Analog output for
control of a 0-10 V modulating hot water valve.
The OE322 Output Expansion Board connects to the VAV/Zone
Controller board by means of a modular cable provided with the
Expansion Board. Power is supplied to the board by means of this
modular cable. Screw terminals are provided for connection of fi eld
wiring to the relay and analog outputs.
The relay outputs are N.O. contacts with one common terminal. Relay
#3 also has an N.C. contact that shares the same common terminal as the
N.O. contacts. All outputs and the relay common are electrically isolated
from all other circuitry on the board. All relay outputs are supplied with
transient suppression devices across each set of contacts to reduce EMI
and arcing. The relay output contacts are rated for pilot duty control of a
maximum of 2 Amps @ 24 VAC or 24 VDC. The analog output provides
a 0 – 10 VDC modulating signal output into a 1K ohm minimum load.
Figure 1: VAV/Zone Controller Dimensions