W
A
TER CONNECTION
WIRING
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3 WATER CONNECTION
3.1 General
The CWP unit has two pair of IN/OUT water connections
(top and front). The unused pair must be securely
capped off. IN/OUT water connections are male BSP
pipe threaded. The unit can be piped directly or using
two temperzone flexible high pressure water hoses
(recommended optional extra) which have tapered
hydraulic female swivel union fittings at each end.
Sediment free water supply is required for correct heat
rejection performance. Ensure water circuit is maintained
and sediment free. Any contaminants may need to be
pre-filtered by external means, particularly where open
cooling towers are used. Unmaintained water quality can
lead to nuisance tripping and premature corrosion.
If a closed loop water system is used, with treatment, it
may be considered unnecessary to have water filtering in
the main supply loop.
Note: Always install isolating valves and a Stat valve
set to ensure the correct CWP design waterflow. It is
recommended that the water supply system be fitted with
a water flow switch and water flow verification circuit.
These items prevent the CWP units from going into fail
safe lockout status due to a loss of water flow.
Failure to install the above items could require the
resetting of all CWP units in the system – by breaking
the power supply to each unit or by Modbus command (if
installed).
3.2 Water Control
A motorised water shut-off valve is supplied built-in and
connected to the UC8 controller; refer wiring diagram.
The valve is closed when the compressor is off.
This valve control system ensures water does not flow
through the unit when it is not operational for a long
period of time, thereby reducing the overall central pump
power usage. The UC8 controller performs a periodic
water-flush-cycle to minimizes the risk of stagnant water
and settling of particulate deposits when the unit is off for
long periods.
3.3 Circuit Balancing Valve
An external circuit balancing valve must be fitted to
maintain water flow at a constant rate. The minimum
water flow rates in litres per second (l/s) are stated in the
supplied Specifications Data sheet.
The CWP unit controller (UC8) will protect the
refrigeration system of the unit under severe operating
conditions. On heating cycle it protects to ensure the
evaporating temperature does not drop below freezing
for an extended period. The extreme lowest leaving water
temperature needs to be such that the unit does not
cut-out on protection and will be above approx. 4°C. This
can be achieved by a combination of the Entering Water
Temperature (EWT) and the reduced flow rate. Water
flow needs to be balanced to suit the system design.
Refer Technical Data for acceptable water flow rates and
pressure drop data.
3.4 Air / Water Flow
Refer to CWP Technical Data pamphlets at
www.temperzone.biz for detailed information on air
handling performance and water flow rates.
3.5 Water Circulating Pump & Flow Verification Options
In order to promote efficiency and avoid running the
water circulation pump unnecessarily, the unit's UC8
Controller can be used to control the activation of the
pump prior to running the compressor. After the activation
signal is sent to the external water circulating pump,
the UC8 waits for the flow verification contact to close
(if present) before starting the compressor (refer wiring
diagram, p.7). The UC8 will also de-activate the pump
when the compressor stops.
3.6 Heating Operation
On heating, the UC8 looks at the entering water
temperature and if this is below 10°C it will activate
the electric standby elements to warm the air stream
and achieve the room thermostat setpoint. If the water
temperature is above 10°C, the CWP will action the
reverse cycle heating and compressor. If the evaporating
temp. consistently stays below -10°C and/or the entering
water temp. drops consistently below 5°C , the UC8 will
stop the compressor and revert to standby electric heat.
4. WIRING
4.1 General
Electrical power wiring must be fitted and certified by
persons with appropriate qualifications and certification
and comply with local and national standards.
Where appllcable, a signed 'Certificate of Compliance'
must be left with the unit for insurance purposes.
4.2 Power to Unit
All power wiring is to be done to the appropriate
electrical standard of the country in which the unit is
being installed.
The person installing the wiring is responsible for the
correct selection of wiring size and auxiliary components.
See the Specification Sheet for supply voltage range,
frequency, phase and maximum operating current .
Wire the unit directly from the Electrical Distribution
Board.
The unit should have its own dedicated circuit breaker
on the Distribution Board and a lockable isolator switch
should be installed in accordance with the applicable
wiring regulations.
4.3 Control
Room Temperature Controller
The thermostat should be set within the recommended
operating range of between 19°C and 30°C.
Various options are available to control the air
conditioning unit operation.
a. Temperzone TZT-100 Wall Thermostat.
Refer to www.temperzone.biz for features and
installation details; model search 'TZT-100'.
Separate 'Installer' and 'User' instructions are
supplied with the TZT-100 for installation and
operation.
b. The Temperzone SAT-3 Wall Thermostat.
Refer to www.temperzone.biz for features and
