Carrier AquaForce 30XAV 1050, Installation, Operation And Maintenance Instructions

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9.7.5 - Corrosion allowances

Gas side: 0 mm

Heat exchange fluid side: 1 mm for tubular plates in lightly 

alloyed steels, 0 mm for stainless steel plates or plates with 
copper-nickel or stainless steel protection.

9.7.6 - Evaporator

30XAV chillers use a flooded multi-tube evaporator. The water 

circulates in the tubes and the refrigerant is on the outside 
in the shell. One vessel is used to serve both refrigerant 
circuits. There is a centre tube sheet which separates the two 
refrigerant circuits. The tubes are 3/4” diameter copper with 
an enhanced surface inside and out. There is just one water 
circuit with two water passes (one pass when 100C is 
selected).

The evaporator has been tested and stamped in accordance 
with the applicable pressure code. The maximum maximum 
standard relative operating pressure is 2100 kPa for  refrigerant 
side and 1000 kPa for water side. These pressures can be 
different depending on the regulation and the code applied.

The evaporator has a thermal insulation of 19 mm thick 

polyurethane foam, aluminium cladding may be fitted as an 

option and is equipped with a water vent and purge. 

The water connection of the heat exchanger is a Victaulic 
connection. As an option the evaporator is available with 
freeze protection (evaporator freeze 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.

9.7.7 - Oil separator

In these units, the oil separator is a pressure vessel that is 
mounted under the outside vertical condenser coils. 
Discharge gas at the compressor outlet is directed towards 
the bottom of the oil separator and most of the oil separates 
from the gas by strong deceleration and by gravity. The gas 

then flows through a wire mesh screen where the remaining 
oil is separated by coalescence and flows to the bottom of 

the vessel. The gas is now free from oil and leaves the vessel 
at the top towards the condenser.

The oil separator is equipped with a trace heater regulated 
by the unit controls.

9.7.8 - Assembly function

The assembly function includes a liquid line valve, a filter 

drier, two EXVs, a plate heat exchanger as well as protection 
devices (seal or valve).

At the condenser outlet a part of the liquid is expanded via 
the secondary EXV in one of the heat exchanger port and 
then returns as gas at the compressor economiser. This 
expansion increases the sub-cooling of the bulk of the liquid 

refrigerant which then flows into the evaporator via the main 
EXV.  This increases both the capacity and efficiency of the 

system.

9.8 - High-pressure safety switch

30XAV units are equipped with high-pressure safety switches.

In accordance with the applicable code the high-pressure 
switches with manual reset, called PZH (former DBK), may 
be backed up by high-pressure switches that require resetting 
with a tool. The high-pressure switches that require resetting 
with a tool are called PZHH (former SDBK). If a PZHH 
cuts out,  the corresponding PZH in the same compressor is 
faulty and must be replaced. The PZHH must be reset with 
a blunt tool with a diameter of less than 6 mm. Insert this 
tool into the opening on the pressure switch and push the 
reset. 

These pressure switches are located at the discharge of each 
compressor.

9.9 - Condensers

30XAV coils are all-aluminium micro-channel condensers. 

9.10 - 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 (level IP55).

All fans in the same refrigerant circuit are controlled by one 
or two variable speed drives. Therefore, they operate together 
at the same rotational speed. The rotational speed at full load 
or partial load of each circuit is controlled by an algorithm 
that continuously optimises the condensing temperature to 
obtain the best energy efficiency (EER) whatever the 
operating conditions.

9.10.1 - Fan motor electrical protection

The motors of a same circuit are electrically protected by the 
variable frequency drive in case of short-circuit, locked rotor 
or general overload. Each variable frequency drive follows 
a variable current characteristic, based on the frequency from 
5 to 50 Hz and the number of fans controlled.

In case of fan failure (in open circuit), the variable frequency 
drive will automatically detect the problem and send an alert 
to the user interface. Refer to the 30XAV control manual for 

the list of alarms specific to this option.