Check The Refrigerant Charge; Unit Maintenance; Control And Safety Devices - Carrier AQUASNAP JUNIOR 30RHV Installation Manual

30RHV

Check the refrigerant charge

• This check becomes necessary after any refrigerant leak or after
the refrigeration circuit has been switched off to replace a
component.
• The best method to correctly charge refrigerant is to completely
empty the refrigerant circuit using refrigerant recovery
equipment.
Then charge the exact quantity of refrigerant according to the
data shown on the unit nameplate. This can be done with
charging equipment of the "Dial-a-charge" type.
• To empty the refrigerant circuit, the refrigerant recovery
equipment has to be connected to the high pressure side and
low pressure side service ports simultaneously (1/2" UNF,
20 threads/inch).

Unit maintenance

The following maintenance operations must be carried out by
qualified personnel.
Cleaning the coil
When necessary, proceed as follows for more careful cleaning of
the coil:
Switch the mains supply OFF.
Remove unit top cover by losening holding screws and lifting
the cover.

Control and safety devices

1. Compressor winding protection
Automatic reset.
This is activated when the temperature of the winding or the the
compressor power input exceed the set limits.
2. Freeze-up protection
This protection device is controlled by the Pro-Dialog Junior
control using the water heat exchanger leaving temperature.
This safety device interrupts unit operation and shows an alarm
code on the display.
3. Cooling control setpoint
This parameter is regulated by the control and factory set to an
entering water temperature of 12°C.
The second set point default value is 14°C and it can be selected
via the Service Interface.
4. Heating control setpoint
This parameter is regulated by the control and factory set to an
entering water temperature of 43,9°C.
5. High pressure switch HIP
Installed on the supply piping, set to 42 bar, with manual
electric reset.
GB - 12
• R-410A refrigerant cylinders contain a dip tube which allows
liquid refrigerant to flow from the cylinder in an upright
position.
Charge R-410A units with cylinder in upright position and a
commercial-type metering device in the manifold hose in
order to vaporize the liquid refrigerant before it enters the
unit. Charge refrigerant into the suction line.
• The above method must be used for heat pump systems
operating in heating, as operating difficulty in the winter season
(iced outdoor coil) impedes stable operating conditions.
Hence the refrigerant charge must be checked.
In cooling only systems, or heat pumps operating in the cooling
mode, the refrigerant charge check can be carried out using the
superheating method; this is only possible, if the ambient
temperature is above 15°C.
Carefully clean the coil with a vacuum cleaner.
Also clean the inside of the fan compartment with a vacuum
cleaner. Replace the unit cover and tighten the screws.
After long shutdown periods and at commissioning:
Energize the system by putting the main switch to ON without
starting the unit.
(The control must be in the OFF position for at least 12 hours
before the initial start up).
Do not disconnect the main switch during the unit operating
season.
6. Low suction temperature protection
Automatic/manual reset (after 6 automatic cycles) based on the
pressure transducer signal installed on the compressor suction
lines.
7. High pressure protection
Automatic/manual reset (after 6 automatic cycles) based on the
pressure transducer signal installed on the compressor discharge
lines.
8. Water flow switch FS
Installed on the water outlet to the heat-exchanger, does not
permit compressor and pump operation if there is no water
flow.
9. Defrost cycle
This operates only if ice is present on the heat exchanger during
heat pump operation.
This function can be operated by the control.
10. Solid state head pressure controller
Changes the fan speed according to the condensing temperature.
Is controlled by the Pro-Dialog Junior control and permits unit
operation up to the specified temperature limits, optimising the
condensing temperature.