OPA 2000RKTM01
Packaged Reverse Cycle R410A
Air Cooled Air Conditioner
GENERAL
This OPA 2000RKTM Outdoor Unit must be
installed in accordance with all national and
local safety codes.
REFRIGERATION SYSTEM
General
The OPA 2000 has four independent
refrigeration circuits and four compressors
to provide the flexibility and economy of
four stage operation, i.e. utilising one or
more circuits as conditions vary, plus the
advantage of staggered starting.
Each refrigeration system has been charged
with HFC-410A (R410A) refrigerant; refer
wiring diagram specification table for
amount. Tapping points are provided to
measure discharge and suction operating
pressures.
Compressors
The compressors are directional scroll
type. The compressor lubricant is polyol
ester oil (POE). Note, this oil absorbs
moisture quickly if exposed to open air.
On commissioning, the compressors must
be checked for correct rotation (refer Start
Up Procedure). A time delay prevents
simultaneous starting of the compressors.
ECONOMISER (Option)
If the outdoor air temperature or heat
content preferably, is below that of the return
air the fresh air damper opens and the return
air damper closes to provide the first stage
of cooling. A spill air facility in the building
may be necessary for when the return air
damper is closed. The fresh air damper
should return to minimum setting and the
return air damper open before compressors
are allowed to operate to provide further
cooling.
INSTALLATION
Positioning
Refer to dimension diagrams for minimum
clearances. If multiple units are to be placed
side-by-side then allow at least 2 m between
coil faces.
Mounting
The unit should be fastened to a firm flat
horizontal base using the holes supplied in
the mounting channels.
When the unit is being installed on a roof it
is recommended that the unit is installed on
a substantial structure with vibration isolating
springs beneath the unit. These springs are
not supplied with the unit.
Flexible duct connections are recommended
between the supply and return ducts and
the unit.
Installation &
Maintenance
Condensate Drain
The condensate drain should be 'U' trapped
outside the unit. The trap should have a
vertical height of at least 100 mm. The drain
should have a slope of at least 1 in 50 and
must not be piped to a level above the unit
drain pipe.
Electrical Requirements
Electrical work must be done by a qualified
electrician. The outdoor unit must be wired
directly from a distribution board by means
of a circuit breaker or H.R.C. fuse, and a
mains isolator provided - preferably close to
the unit.
Note: DO NOT USE REWIRABLE FUSES.
The OPA 2000 is provided with a 24V AC
control circuit for a thermostat, on/off switch
and/or time clock.
The control transformer 240V primary
voltage is used for countries with 230-240V
power supply. For countries with supply
voltages 200-220V, change the primary
voltage on the transformer to 208V.
Standard units are suitable for use with
thermostats with either manual Heat/Cool
selection or automatic changeover subject
to the contact ratings of the thermostats.
A 24 hour power supply to the control circuit
is required, otherwise the warranty is void.
CHECK TESTS
1. Check that the shipping block beneath the
compressor has been removed and that
the compressor is secure on its mounts.
2. Check by hand that all fan motors can
turn freely.
3. Check that the air filters have been
correctly installed, if fitted.
4. Check air diffuser dampers are open if
appropriate.
5. Check that the thermostat, or external
24V controller, is correctly wired to the
unit and is set at the desired temperature.
6. Check the tightness of all electrical
connections and sign the check label.
7. Leave the thermostat, or external 24V
controller, in the off position and close the
mains isolating switch. (A four hour delay
period is required to allow the crankcase
heater to drive any liquid refrigerant out of
the compressor oil.)
8. Check the supply voltage between each
phase and neutral.
START UP PROCEDURE
After the four hour delay for the crankcase
heater has expired, use the supplied
Commissioning Sheet (Form NS 228) to
record results when completing the following
‘Start-up’ procedure. A UC6 Service
Interface tool is supplied to read, pressures,
superheat and its set-point, compressor
amps etc.
1. Select a sensible Fan speed (or Auto Fan
mode), operating cycle (cool or heat), and
room temperature set point, depending on
the time of year, such that the compressor
will start and run at a high capacity.
2. Turn ON the thermostat / External
controller. Wait for the compressors to
start.
3. Compressors fitted are directional. Check
for correct rotation. If rotation is incorrect
the compressor will not pump, be noisy,
and will draw minimal current. To correct
motor rotation, change the phasing at
the main power terminal. If changing the
phasing, check the indoor air fan then
runs in the correct direction also.
3. Measure the current draw on each phase
to the compressor motors and measure
the current draw of each fan motor.
Check all readings against the specified
values in the wiring diagram.
4. Use the UC6 Service Interface tool to
check operating pressures and status. If
the UC6 Service Interface is not available,
fit gauges and measure the suction and
discharge pressures of both refrigeration
circuits.
5. Check that the outdoor air fan motors are
running smoothly and drawing less than
the full load amps specified.
6. Test the operation of the reversing valve
by running the unit in both the heating
and cooling mode.
7. Check the supply air flow at each outlet.
8. Touch up any outdoor unit paintwork
damage to prevent corrosion.
SETTING SUPPLY AIR FLOW
Consult OPA 2000 Technical Data pamphlet
at www.temperzone.biz for details of airflow/
duct static pressure, if required.
If the indoor air returning to the unit is
regularly expected to be above 50%RH,
then the coil face velocity should be limited
to be 2.5 m/s or less (refer Air Handling
graph in Technical Data pamphlet).
High humidity levels can occur in tropical or
subtropical conditions, and/or when heavily
moisture laden fresh air is introduced.
OPEN
DRAIN
MINIMUM
SLOPE
20 mm PER m
(1 IN 50)
100 mm
MINIMUM
200 mm
APPROX.
'U' TRAP
100 mm
APPROX.
VENT PIPE
FOR LONG
CONDENSATE
DRAIN RUNS
