Riello 20120391, Instructions For The Installer And For The Technical Support Service

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GENERAL INFORMATION
1.3 Description of the device
NXC and NXH are machines designed for commercial applica-
tions such as the air-conditioning of offices and hotels. The
units use the R410A refrigerant gas and are equipped with
scroll type compressors, fitted on anti-vibration supports and
acoustically insulated with specific covers. Moreover, fans fea-
ture helicoidal blades, designed to reduce noise emissions. The
refrigerant block is fully in aluminium and the whole hydron-
ic part is insulated with armaflex. Some models are already
equipped with a circuit with a high head fixed speed pump (1P)
but other configurations are also available as options (for fur-
ther details see the documentation and the catalogue list). All
electric connections are inside the machine that is fully wired
with pins that make electric panel maintenance easier. Power
supply is three-phase with 50 Hz frequency. All control and ad-
justment elements of the machine are controlled and managed
from the touch screen control panel integrated in the machine.
There is also the possibility to manage the machine through
dry contacts.
1.4 Main devices of the equipment
1.4.1 Safety and adjustment devices
Equipment safety and adjustment on the cooling circuit can be
obtained using the following devices:
− high pressure switches with automatic reset devic-
es placed on the high pressure side. These devices are
placed on the drain of each circuit and have a triggering
pressure set to 45 bar;
− two pressure transducers placed on the high and low
pressure line, transmitting the detected value to the
control panel that stops the equipment in case of refrig-
erant anomalous pressure;
− one temperature sensor placed on the low pressure line;
− two discharge valves placed near the plate exchanger
and the heat exchanger.Equipment safety and adjust-
ment on the hydraulic circuit can be obtained instead
using the following devices:
− probes for detecting the delivery and return water tem-
peratures, which intervene on the compressor's opera-
tion;
− two pressure transducers upstream and downstream the
exchanger (if hydronic module is present inside the ma-
chine);
− one flow switch at water inlet of machines that do not
feature the hydronic kit;
− heating element placed at plate exchanger water inlet;
− automatic air vent valve;
− safety valve with triggering pressure set to 4 bar;
− expansion tank;
− water intake and discharge valves;
− integrated mesh filter.
The installer must equip the system with the following:
− an appropriately sized technical water accumulation
tank
− one by-pass valve between device delivery and return
to allow the anti-freeze logics to intervene in case of a
temporary shutdown during winter time.
For further details refer to chapter "Hydraulic connections".
9
Safety device replacement must be carried out by R
Technical Support Service, using only original components.
Please refer to the spare parts catalogue.
0
IT IS FORBIDDEN to operate the device with safety devices
not working.
1.4.2 Other devices
COMPRESSORS
The units use hermetic scroll compressors.
Each compressor is equipped with a heating element for casing
oil. Heating element faults cannot be detected.
Each compressor sub-unit is equipped with:
− anti-vibration supports between unit frame and com-
pressor sub-unit frame;
− one safety pressure switch on the drain line of each cir-
cuit;
− temperature and pressure sensors on the common in-
take line and a pressure sensor on the common drain
line.
The compressors fitted on the units feature an oil charge en-
suring good lubrication in all working conditions. In case of oil
leak, proceed in the following way: find it, repair it and then
refill with refrigerant and oil again.
For oil removal and filling procedures, see the Service Manual.
FANS
Each fan motor is equipped with a high performance impeller
made up of a recyclable composite material. Three-phase mo-
tors with permanent lubrication bearings and insulation class
F (IP55 classification).
For more detailed information, refer to the table below.
Product/Option
Standard
version NXC
(1)
or with mute
Version Option
Standard
version
NXC (2)
Fan overall efficiency 32.90 35.40 %
Measurement category Static -
Efficiency category A A -
Target energy efficiency 40 40 -
Efficiency level at its op-
timal energy efficiency
40 40 -
Frequency converter
NO NO -
Year of manufacture See unit label -
Fan manufacturer ebm-papst -
Motor manufacturer ebm-papst -
Motor rated power 0.75 1.85 kW
Flow rate 12710 17830 cu.m/s
Pressure 69 130 Pa
Rotation speed 695 930 rpm
Specific ratio 1 1 -
Motor type
Asynchronous with double
speed
-
Pole quantity 8 6 no.
Rated frequency at inlet 50 50 Hz
Rated voltage 400 400 V
Number of phases 3 3
Ambient air temperature
(for which the fan motor
is designed)
+70 +65 °C
(1) For NXC size from 044 to 064 and from 096 to 122, only.
(2) For NXC size from 072 to 084 and from 142 to 164, only.