Roof Top Units
HA / 34 /45 /52 /61 / 75 / 89 / 110 RC
Roof Top Unit
11
Any modifications carried out without the approval of Airwell may void the unit warranty.
Mains supply cables must be sized to ensure adequate voltage at the unit terminals when the unit is starting and
during full load operation.
Selection of supply cables must be determined by the following criteria:
1. Length of run supply cables.
2. Maximum starting current of unit cables must supply adequate voltage at unit terminals for starting.
3. Method of installation of supply cables.
4. Capability of cables to carry unit full load current.
Starting and full load currents are provided on the units circuit diagram.
Short circuit protection must be provided at switchboard using HRC fuses or circuit breakers.
Where the choice of room controls includes either a remote room sensor and/or a set point unit these must be wired
in shielded cable and must not be run in the conduits with the power wiring (240/415 volt) as any induced voltage will
cause unreliable operation of the unit.
PLEASE NOTE
It is essential that the location selection for the thermostat sensor is representative of the space to be controlled and
where it will be readily affected by changes to the general space temperature.
Location adjacent to or in line with supply air outlets, or where its operation may be affected by direct sunlight,
outside doors or other external influences must be avoided.
The wire entry point must also be thoroughly sealed to prevent draughts influencing the operation of the sensor.
Failure to observe the above requirement may result in erratic and unreliable operation of the unit.
REFRIGERANT CHARGE
This heat pump is shipped pre-charged with the correct amount of R22 in the system. At unit start up, the operating
pressures and temperatures should be checked to verify the unit is properly charged by a qualified refrigeration
mechanic.
WWARNING
s.
DEFROST CYCLE DRAINAGE
During the heating cycle ice forms on the surface of the outdoor coil. This ice is periodically removed during the units
defrost cycle and fairly large quantities of water (melted ice) will be dumped onto the area beneath the unit. Where
the unit is mounted on a roof this should not be a problem. However, where the free run off of this water is not
acceptable a drain tray of at least 75 mm deep and extending 75mm outside the units dimensions must be installed
beneath the unit and drain piping connected to it.
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DUCTING REQUIREMENTS
All duct designs and heat loads must be calculated by a qualified air conditioning consultant or contractor in
accordance with normal good ducting practices.
Dimensions of duct connections are shown on the dimension sheet. Connection to the unit must be made via
flexible connections to prevent transmission of vibration and facilitate easy removal of panel work for major service
access. All ductwork must be insulated against noise and heat transmission.
FRESH AIR INTAKE
If required this must be fitted to the return air ducting as no special provision is made within the unit. All fresh air
intakes must be provided with air filters if they are connected to the ductwork between the return air filter and the
unit.
AIR FILTERS
Air filters are not provided and no provision is made for fitting them within the unit as standard. Air filters should
however be provided by the installing contractor and located in an accessible location between the return air grille
and the unit. These filters must be sized for a maximum face velocity of 2.0 m/sec.
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ELECTRICAL INSTALLATION
The electrical installation must be carried out by a competent licensed electrician in accordance with local power
supply authority regulations and the appropriate unit wiring diagram.
PLEASE NOTE
INSTALLATION
