OPA 330RKT
Packaged Reverse Cycle R410A
Air Cooled Air Conditioner
GENERAL
This OPA 330RKT unit must be installed
in accordance with all national and local
safety codes.
CONFIGURATIONS
The OPA 330RKT is supplied in one of two
standard configurations :
1. Horizontal supply/return air with box
mounting channel (RKTH), or
2. Downward supply air with box mounting
channel (RKTU).
REFRIGERATION SySTEm
General
The refrigeration system has been charged
with 9.7 kg each of HFC-410A (R410A)
refrigerant. Tapping points are provided to
measure discharge and suction operating
pressures.
Compressors
The compressor is 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 compressor must be
checked for correct rotation (refer Start Up
Procedure).
ECONOmISER (Option)
If the outdoor air heat content or
temperature 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. The compressor will then
operate to provide more cooling if required.
INSTALLATION
Unpacking
Units configured with Downward supply air
and mounting rails, have their spigots
shipped loose inside the return air cavity.
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 box mounting channel.
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.
Installation &
maintenance
Flexible duct connections are recommended
between the supply and return ducts and
the unit.
Condensate Drain
The condensate drain should be 'U' trapped
outside the unit. The trap should have a
Downward 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 (see figure 3).
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 330 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 compressor
crank case heater is required, otherwise the
warranty is void.
CHECK TESTS
1. Leave the on/off switch in the off position
and close the mains isolating switch.
A four hour delay period is required to
allow the crankcase heaters to drive any
liquid refrigerant out of the compressor oil.
2. Check that the shipping block beneath the
compressor has been removed and that
the compressor is secure on its mounts.
3. Check that all fan motors are free running.
4. Check that the thermostat is correctly
wired to the unit and is set at the desired
temperature.
5. Check that the air filters have been
correctly installed if fitted.
6. Check air diffuser dampers are open if
appropriate.
START UP PROCEDURE
Use the supplied Commissioning Sheet to
help you complete the following procedure:
1. After the four hour delay period has
expired, switch on the unit.
2. The compressor fitted is 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. Check the supply voltage between each
phase and neutral.
4. Measure the current draw on each phase
to the compressor motor and measure the
current draw of each fan motor. Check all
readings against the specified values in
the wiring diagram.
5. Fit gauges and measure the suction and
discharge pressures of both refrigeration
circuits.
6. Check that the outdoor air fan motors are
running smoothly.
7. Test the operation of the reversing valve
by running the unit in both the heating
and cooling mode.
8. Check the indoor unit's fan belt tension
after 20 mins of operation and adjust if
necessary (refer Commissioning Sheet).
9. Check the supply air flow at each outlet.
10.Check the tightness of all electrical
connections and sign the check label.
11.Touch up any outdoor unit paintwork
damage to prevent corrosion.
SETTING SUPPLy AIR FLOW
Consult OPA 330 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,
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.
Select a fan speed that avoids water carry-
over problems.
In a free blow or low resistance application,
beware of exceeding the fan motor's full
load amp limit (refer wiring diagram).
The indoor air fan motor is fitted with
a factory set adjustable pitch pulley.
Instructions for the adjustment of pulleys is
included on the back page of the supplied
Commissioning Sheet. One revolution of
adjustment is equal to approx. 7% change
in air volume flow rate.
