TemperZone OPA 550RKTB Maintenance and service guide





This OPA 550RKTB Outdoor Unit must be
installed in accordance with all national and
local safety codes.

The OPA 550RKTB is supplied in one of
two standard congurations :
1. Horizontal supply/return air with box
mounting channel (RKTBH), or
2. Downward supply/return air with box
mounting channel (RKTBU).


The OPA 550 has two independent
refrigeration circuits and two compressors
to provide the exibility 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
specication table for amount. Tapping
points are provided to measure discharge
and suction operating pressures.

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.

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
rst 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. A low limit
thermostat is tted to prevent compressors
operating with a mixed air-on coil
temperature below 18°C; resets at 20°C.
This is by-passed during heating mode.


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.



The unit should be fastened to a rm at
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.

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 (refer Fig. 3).

Electrical work must be done by a qualied
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.
: DO NOT USE REWIRABLE FUSES.
The OPA 550 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 heaters is required, otherwise the
warranty is void.

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.
Bypass the crankcase heater thermostat
(CCHT) for this period only
2. Check that the shipping blocks beneath
each compressor have been removed
and that each 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 lters have been
correctly installed if tted.
6. Check air diffuser dampers are open if
appropriate.

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. Ensure the
crankcase heater thermostat has been
reconnected.
2. Check the supply voltage between each
phase and neutral.
3. Compressors tted 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 on each phase
to the compressor motors and measure
the current draw of each fan motor.
Check all readings against the specied
values in the wiring diagram.
5. Fit R410A compatible 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 ow 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.

Consult OPA 550 Technical Data pamphlet
for details of airow/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 tted 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 ow rate.

The Outdoor Unit Controller (OUC)
includes a temperature sensing head
pressure control which enables the system
to compensate for outdoor ambient
temperatures below 20°C on cooling cycle,
and above 15°C on heating cycle. The OUC
also has features which protect against icing
or overheating of coils, rapid cycling of the
compressor and loss of refrigerant charge.
If the outdoor air fans take some time
to begin rotating when the system is
powered on, or they don't appear to be
rotating appropriately while the compressor
is running, consult the OUC label on
the electrical box. If necessary, refer
to for further diagnostic
information.


Not to Scale
535
SUPPLY
AIR
RETURN
AIR
190 483 497
130
MOUNTING CENTRES 1879
MOUNTING CENTRES
310
2225
1950
1750
OVERALL
OUTDOOR
AIR FLOW
OUTDOOR
AIR FLOW
OPTIONAL
WEATHER
HOOD
1000 MIN. CLEARANCE
500 MIN. CLEARANCE
OPTIONAL
WEATHER
HOOD
695
955
ACCESS
PANEL
735
UVW
X
Y
Z
DRAIN
1" BSP
FEMALE
1000 MIN.
CLEARANCE
FOR FILTER
ACCESS
500 MIN. CLEARANCE
FILTER
ACCESS
60
2335 O/A
35
ACCESS
PANEL
1080 1080
 
PROJECTION
POINT LOads (kg)
U V W X Y Z
160 136 111 132 148 164
 A 2 m clearance
is required above the
exhaust air fans
Net Weight 851 kg


1. Check air lters, if tted, and vacuum or
wash clean as necessary.
2. Check condensate drain for free
drainage.
3. Check compressor compartment for oil
stains indicating refrigerant leaks.
 (or every 1200 hrs of operation)
Check the indoor unit's fan belt tension and
adjust if necessary.

1. Check the tightness of electrical
connections.
2. Check the tightness of all fans, motor
mountings, pulleys and belt tension.
3. Check suction and discharge operating
pressures.
4. Replace indoor air lters (if tted).
5. Check condensate drain for free
drainage.

1. Check all refrigerant piping for chang
and vibration.
2. Check the operation of electric heaters,
if tted.
3. Check air supply at all diffusers.
4. Check for excessive noise and vibration
and correct as necessary.
5. Check outdoor air fan and motor bearings
and lubricate or replace as necessary.
Note: Indoor air fan bearings are sealed
and lubed for life.
6. Check for insulation and duct damage
and repair as necessary.
7. Remove lint and dust accumulation from
outdoor coil ns.
8. Touch up any paintwork damage to
prevent corrosion.

The manufacturer reserves the right to
make changes in specications at any time
without notice or obligation. Certied data is
available on request.
This pamphlet replaces the previous
issue no. 3711 dated 12/13.
Wiring revision C.


Not to Scale
PROJECTION

The manufacturer reserves the right to make
changes in specications at any time without
notice or obligation. Certied data is available
on request.
 
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
OUTDOOR
AIR FLOW 185
215
475
608
435
930
205
120
483
OUTDOOR
AIR FLOW
60
 

04/14 Pamphlet No. 3711 © temperzone limited 2014