AERMEC NYB, Installation Manual

18

20.05 – 4138421_03

COMMISSIONING - WARNINGS

Please note that, on request by the Aermec customer or the legitimate 

owner of the machine, the units in this series can be started up by 

the AERMEC After-Sales Service in your area

 (valid only on ITALIAN 

territory). 

The start of operation must be scheduled in advance based 

on the time frame for the completion of works for the system. Prior to the 

intervention, all other works (electrical and hydraulic hook-ups, priming 

and bleeding of air from the system) must have been completed.

START-UP

OPERATIONS TO BE PERFORMED WITH NO VOLTAGE PRESENT

 ATTENTION 

the unit is not working:

Check:

-  All safety conditions have been respected

-  The unit is correctly fixed to the support surface

-  The minimum technical spaces have been respected 

-  That the main power supply cables have appropriate cross-section, 

which can support the total consumption of the unit. (see electric 

data sections) and that the unit has been duly connected to the 

ground.

-  That all the electrical connections have been made correctly and all 

the terminals adequately tightened.

-   Check for refrigerant gas leaks, especially near the pressure points 

of pressure gauges, pressure transducers and pressure switches. 

(vibrations during transport may have loosened the connections).

OPERATIONS TO BE PERFORMED WITH THE UNIT LIVE

ATTENTION 

the unit is still not working:

-  Supply power to the unit by turning the master switch to the ON 

position.

-  Use a tester to verify that the value of the power supply voltage to 

the phases is equal to 400V ± 10%; also verify that the unbalance 

between phases is no greater than 3%.

-  Check that the connections made by the installer are in compliance 

with the documentation.

-  Verify that the resistor of the compressor sump is working by 

measuring the increase in temperature of the oil pan. The resistance/s 

must function for at least 12 hours before start-up of the compressor 

and in any event, the temperature of the oil pan must be 10-15°C 

higher than room temperature.

HYDRAULIC CIRCUIT CONTROLS

-  Check that all hydraulic connections are made correctly, that the 

plate indications are complied with and that a mechanical filter has 

been installed in each inlet heat exchanger. 

(Mandatory component 

for warranty to be valid).

-  Make sure that the circulation pump/s is operating and that the 

water flow rate is sufficient to close the contact of the flow switch, if 

installed.

-  Check the water flow rate, measuring the pressure difference 

between inlet and outlet of the evaporator and calculate the flow rate 

using the evaporator pressure drop tables present in this manual.

-  Check the correct functioning of the flow meters if installed. Closing 

the cut-off valve at the output of the heat exchanger; the unit control 

panel must show the block. Finally re-open the valve and rearm the 

block

COMMISSIONING

-  Once all the aforementioned checks have been carried out, the unit 

can be commissioned

-  Close the door of the electrical panel.

-  Set the unit main switch to ON, the unit will start after a few minutes

OPERATIONS TO BE PERFORMED WITH MACHINE ON

 ATTENTION 

the unit is working:

Check:

-   That the compressor input current is lower than the maximum 

indicated in the electrical data table.

-   Before starting the unit, check that the compressor rotates in the 

correct direction through a three-phase protection. The spiral 

compressors compress in one direction of rotation only. Therefore, 

it is essential for the phase of the three-phase spiral compressors 

to be correctly connected (the correct direction of rotation can be 

controlled when the pressure on the intake side decreases and that 

on the flow side increases with the compressor in operation). If the 

connection is incorrect, the direction of rotation is reversed: this 

causes a loud noise and the reduction of current consumption. In this 

case, the protection system inside the compressor activated turning 

off the unit. To solve the problem, disconnect and swap the wires 

between two of the phases, then connect the three-phases again.

-   That the voltage value lies within the pre-fixed limits and that 

unbalance between the three phases (three-phase power supply) is 

not above 3%.

If having to take measurements and perform checks that require the 

machine to run, you must:  

-  make sure that any remote control systems are disconnected; 

however, keep in mind that the PLC on the machine controls its 

functions and can enable and disable the components creating 

hazardous situations (e.g. power and rotate the fans and their 

mechanical drive systems). 

-  Operate with the electrical board open the shortest time possible

-  Close the electrical board as soon as the single measurement or 

control is performed  

ATTENTION

The anti-freeze set temperature can only be varied by an authorised 

after-sales centre and only after having checked that there is a suitable 

% of anti-freeze solution in the water circuit.

Whenever this alarm intervenes, call the nearest authorised after-sales 

service immediately

- Control of the water flow rate alarm, the unit provides for the 

management of a flow rate alarm controlled by a differential pressure 

switch or flow switch if provided. This type of safety device intervenes 

after the first 30 seconds of pump functioning, if the water flow rate is 

not sufficient. The intervention stops the compressor and the pump 

itself.

COMMISSIONING - WARNINGS