- 3 -
Figure 3. Pressurisation bung locations
4. CONTROLS
4.1 Electrical Requirements
Electrical work must be done by a qualified electrician.
DANGER! LIVE ELECTRICAL CONNECTIONS. DISCONNECT MAINS
POWER BEFORE WORKING ON UNIT. ONLY QUALIFIED PERSONS
WHO ARE COMPETENTLY TRAINED SHOULD PERFORM SERVICE AND
MAINTENANCE TASKS.
The outdoor unit must be wired directly from a distribution
board by means of a circuit breaker and a mains isolator
provided – preferably close to the unit.
Note:
DO NOT USE REWIRABLE FUSES.
A 24 hour power supply to the compressor crank case
heaters is required, otherwise the warranty is void.
4.2 Control options
These OPA Econex (-DZ) units are controlled using the
Smart Temp RS-SSD wall control (indoor Smart Sensor).
Other options include the following:
• 24V AC and 0-10V signals from an external controller or
thermostat
• Remote on/off switch and/or time clock
• Modbus RTU serial communications over RS485
connection
• BACnet-IP serial communications over Ethernet
connection (with optional gateway module)
Standard reverse cycle units are suitable for use with
thermostats and controls with manual heating/cooling
selection or automatic change-over.
A unit wiring diagram is supplied alongside the electrical
board and in the Specifications document
.
4.3 Remote on/off
The UC8 has an input for a remote on/off function on
terminal ‘On’, signal return is terminal ‘0V’. When used the
remote on/off terminals should connect to a voltage-free
relay contact. When not used the remote on/off terminals
should be shorted (‘looped’) – refer wiring diagram.
4.4 Capacity control
OPA Econex units offer the following capacity control
options:
• Automatic control when the unit connects to the
RS-SSD
wall control.
• 0-10V compressor control signal via terminal ‘VC’ on the
UC8 circuit board, signal return is terminal ‘0V’.
• 0-10V indoor fan control signal via terminal ‘VF’ on the
UC8 circuit board, signal return is terminal ‘0V’.
• Control by a building management system via Modbus
RTU or BACnet-IP serial communications.
4.5 Unit Controller (UC8)
The unit’s UC8 controller receives requests such as ‘Unit
On/Off’, ‘Start compressors’, ‘Activate HEAT (Reverse
Cycle)’ and transfer the requests to the outputs after
enforcing safety timers.
Figure 4. UC8 Controller
The Unit Controller provides several system protection
functions. These are covered in Appendix I (p.9).
For additional information, refer to the UC8 Controller label
on the unit or www.temperzone.biz for operation & fault
diagnostics information; model search ‘UC8’.
References available:
UC8 Operation Manual : Air-to-Air Units
UC8 Fault & Display Messages (as per unit label)
UC8 Quick Reference and Operation Fault Diagnosis
UC8 Troubleshooting Guide
UC8 Modbus Communications
UC8 BACnet Communications
UC8 Master-Slave Connection
4.6 Viking Controller for Economiser/Economy Cycle
OPA Econex (-DZ) units utilise: (i) Viking SMT-920 HVAC
Controller, (ii) RS-SS outdoor air temp. & humidity sensor,
and (iii) RS-SSD wall control (aka indoor Smart Sensor).
Air Quality (CO
2
) sensors, 0–10V, are available to work with
this Controller.
The controlller is factory set for ‘Enthalpy control’
to comply
with Australian NCC and NZ Building Code.
Refer Section 6.3 Operation for more information.
4.7 Viking/Smart Temp RS-SSD wall control
Connect the RS-SSD to the unit using a shielded twisted
pair type cable, suitable for RS485 communications. Signal
wires 1 and 4 should form one twisted pair.
Note
: The cable shield must be connected to a suitable
Earth. Do not connect at both ends.
RS-SSD has its own DIP switches that are factory preset,
as per OPA unit wiring diagram.
Connect the thermostat as follows:
RS-SSD Connection:
S1 S2 S3 S4
Smart Sensor
Viking HVAC Controller
RS-SSD
1
2
3
4
Shielded twisted
pair 4 core
Shared with
RS-SS outdoor
air sensor
Note: The RS-SSD can not be used simultaneously with a
2-wire remote sensor.
Refer RS-SSD Manual for installer options and use.
LCD Display
Push button
©temperzone Ltd 2021
Standard hand unit
Opposite hand unit
