WattMaster MG331-21-VAVCAV - Manual (Page 3)

Form: WMS-OE322-3Relay-1AnOutExpBrd-1C.doc
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VAV System
Description
The OE322 - 3 Relay with Analog Out-
put Expansion board is used in conjunc-
tion with the MG320–00-VAVZ control-
ler board to allow for control of VAV
terminal units, including series and par-
allel fan terminal units with up to 3
stages of electric heat, SCR electric
heat or with modulating hot water heat.
The OE322 Analog Output Expansion
board provides 3 relay outputs for pilot
duty switching control, and 1 Analog
output for control of a 0-10V modulating
hot water valve or SCR controlled elec-
tric heating coil. The expansion board is
also equipped with 24 VDC (+V and
GND) output terminals for powering a
24 VDC hot water valve actuator if de-
sired. A 24 VAC hot water valve actua-
tor can also be used but will require the
use of a separate field supplied 24 VAC
transformer to power the valve actuator.
The OE322 - 3 Relay W/ Analog Output
Expansion board connects to the
MG320–00-VAVZ controller board by
means of a modular cable provided with
the OE322 board. Power is supplied to
the board by means of this modular ca-
ble. Screw terminals are provided for
connection of field wiring to the relay
and analog outputs.
The relay outputs are N.O. contacts with one common terminal. 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. The 24 VDC (+V and GND) output terminals are rated for control of a 24 VDC
valve actuator with a maximum load rating of 12 Watts or less.
Mounting
The OE322 - 3 Relay W/ Analog Output Expansion Board is supplied mounted on a plastic Snap Track channel.
The Snap Track channel has two mounting holes which are used to field mount the board with the provided
screws. The board should be mounted in close proximity to the MG320–00-VAV controller board to allow for con-
nection of the modular cable.
Technical Data OE322- 3 Relay W/ Analog Output Expansion board
Operating Temp 10
°F to 149°F Operating Humidity 90% RH Non-Condensing
Weight 4 oz Connection to Controller: Modular Cable
Outputs:
Analog Output Qty. 1 Analog Output Rating 0-10 VDC @ 1k Ohm minimum load
Relay Output Qty. 3 – Electrically Isolated Relay Contact Rating 2 Amp @ 24 VAC
Valve Actuator Power
Terminals Voltage 24 VDC 24 VDC Valve Actuator
Maximum Load
12 Watts
Three Year Warranty WattMaster reserves the right to change specifications without notice
OE322 - 3 Relay W/ Analog Output
Expansion Board
4.18"
3.00"