Major System Components; Compressors; Lubricant; Air Heat Exchangers (Condensers In Cooling Mode, Evaporators In Heating Mode) - Carrier AQUASNAP 30RQ Installation, Operation And Maintenance Instructions

10 - MajOR sYsTEM COMPONENTs

10.1 - Compressors

30RQ units use hermetic scroll compressors.
Each compressor is equipped with a crankcase oil heater, as
standard, complete with a safety device that prevents compressor
start-up if there is a fault at the heater.
As standard, each compressor is equipped with a discharge
valve. As an option each compressor can be equipped with a
suction valve (option No. 92).
Each compressor sub-function is equipped with:
• Anti-vibration mountings between the unit chassis and the
chassis of the compressor sub-function.
• Suction piping equipped with openings (not visible) to
ensure an even oil level between all compressors.
• A non-return valve at the discharge of all compressors.
• A pressure safety switch at the discharge of all compressors,
located between the compressor and the valve.

10.2 - lubricant

The compressors installed in these units have an oil charge of
6.7 l to ensure their correct operation.
The oil level check must be done with the unit switched off,
when then suction and discharge pressures are equalised. The
oil level must not be visible in the sight glass (level below the
sight glass). If this is not the case, there is an oil leak in the
circuit. Search and repair the leak, then recharge oil, so that it
reaches a high sight glass level, when the unit is recharged with
refrigerant. The refrigerant dissolved in the oil raises the level -
do not add any more oil.
ATTENTION: Too much oil in the circuit can cause a unit
defect.
NOTE: Use only oils which have been approved for the
compressors. Never use oils which have been exposed to air.
CAUTION: R22 oils are absolutely not compatible with
R410A oils and vice versa.
10.3 - air heat exchangers (condensers in cooling
mode, evaporators in heating mode)
The 30RQ air heat exchangers are air-cooled condensers in
cooling mode with integrated sub-coolers and internally finned
copper tubes with aluminium fins.

10.4 - Fans

The fans are axial Flying Bird fans equipped with rotating
shroud and made of composite recyclable material. Each motor
is fixed with transverse supports. The motors are three-phase,
with permanently lubricated bearings and insulation class F.

10.5 - Electronic expansion valve (EXv)

The EXV is equipped with a stepper motor (2785 to 3690
steps, depending on the model) that is controlled via the EXV
board.
The EXV is also equipped with a sightglass that permits verifi-
cation of the mechanism movement and the presence of the
liquid gasket.

10.6 - Moisture indicator

Located on the EXV, permits control of the unit charge and
indicates moisture in the circuit. The presence of bubbles in the
sight-glass indicates an insufficient charge or non-condensables
in the system. The presence of moisture changes the colour of
the indicator paper in the sight-glass.
10.7 - Refrigerant storage tank with integrated filter
drier
This component has three system functions. It permits storing
the excess refrigerant in the heating mode of heat pumps. The
optimised maximum unit charge volume for 30RQ units is
determined in the cooling mode (see physical data table).
The refrigerant storage tank prevents flooding of the shell-and-
tube heat exchanger in the heating mode.
A metallic filter and a removable dehydrating filter element
keep the refrigerant circuit dry and clean by retaining solid
polluting particles.
The moisture indicator integrated into the EXV indicates when
it is necessary to change the removable filter element.

10.8 - Water heat exchanger

The water heat exchanger is a shell-and-tube type with two
refrigerant circuits. It has been tested and stamped in
accordance with applicable pressure codes for a maximum
operating pressure of 4500 kPa refrigerant-side and 1000 kPa
water-side. The seamless copper tubes are finned on the
refrigerant side and expanded into the tube sheets. The water
connection of the heat exchanger is a Victaulic connection.
The heat exchanger has a thermal insulation of 19 mm thick
rubber foam, and is equipped with a water drain and purge. An
option with an aluminium jacket is also available.
As an option the heat exchanger is available with frost protec-
tion ('water heat exchanger frost protection' option).
The products that may be added for thermal insulation of the
containers during the water piping connection procedure must
be chemically neutral in relation to the materials and coatings
to which they are applied. This is also the case for the products
originally supplied by Carrier.
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