OPA 1370RKTM01
Packaged Reverse Cycle R410A
Air Cooled Air Conditioner
GENERAL
This OPA 1370RKTM Outdoor Unit must be
installed in accordance with all national and
local safety codes.
REFRIGERATION SYSTEM
General
The OPA 1370 has four independent
refrigeration circuits and four compressors
to provide the flexibility and economy of
two stage operation, i.e. utilising one or
two 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 mounts or pads beneath 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 1370 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 all the shipping bolts on the
back of the compressor frame have 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.
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 compressor to
start. Measure the current for each
phase feeding into the compressor’s.
Compare against the compressor amps
specified on the unit’s wiring diagram.
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.
4. Measure the current draw of each fan
motor. Check all readings against the
specified values in the wiring diagram.
5. 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.
6. Check that the outdoor air fan motors are
running smoothly and drawing less than
the full load amps specified.
7. Check the indoor unit's fan belt tension
after 20 mins of operation and adjust if
necessary (refer Commissioning Sheet).
8. Test the operation of the reversing valve
by running the unit in both the heating
and cooling mode.
9. Check the supply air flow at each outlet.
10. Touch up any outdoor unit paintwork
damage to prevent corrosion.
SETTING SUPPLY AIR FLOW
Consult OPA 1370 Technical Data pamphlet
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,
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
