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INXWPY. 1610. 4438880_01
12. OPERATION
CHARACTERISTICS
12.1. COOLING SET POINT
(Default defined) = 7°C, ∆t = 5°C.
12.2. HEATING SET POINT
(Default defined) = 45°C, ∆t = 5°C.
In case of restoring of the unit supplied power after a momentary interruption,
the pre-set mode is maintained in memory.
12.3. COMPRESSOR START-UP DELAY
To prevent the compressor start too close to each other, two functions have
been arranged.
- Minimum time from last turnoff 60 seconds.
- Minimum time from last start 300 seconds.
12.4. CIRCULATION PUMP
The electronic board provides an output to manage the circulation pump.
After the first 10 seconds of pump operation, when the water flow rate is
running, activate the function of water flow rate alarm (flow switch).
12.5. ANTI-FREEZE ALARM
The anti-freeze alarm is active as if the machine is turned-off or if the machine
is in standby mode. In order to prevent breakage of the plate-type exchanger
due to freezing water contained, the compressor is locked (if the machine is
turned on under 4° C) and the heater starts up (if standby below 5° C). If the
temperature detected by the probe in the exchanger output and in the chiller
input is below +4 ° C.
WARNING
THE ANTI-FREEZE SET TEMPERATURE CAN BE VARIED ONLY BY AN
AUTHORISED SERVICE CENTRE AND ONLY AFTER VERIFYING THAT IN THE
WATER CIRCUIT IS AN ANTIFREEZE SOLUTION.
The intervention of this alarm sets the compressor block and not of the pump
block, which remains active, and the heater starts up if installed.
For resetting the normal functions, the water output temperature has to be
over +4 ° C, the reset is manual.
WARNING:
AT ANY INTERVENTIONS OF THIS ALARM IT IS RECOMMENDED TO
IMMEDIATELY CONTACT THE NEAREST TECHNICAL SERVICE ASSISTANCE
12.6. WATER FLOW RATE ALARM
The PGD1 provides the management of a water flow rate alarm commanded
from a flow switch installed on the machine as standard. This safety type can
occur after the first 10 seconds of operation of the pump if the water flow rate
is not sufficient.
This alarm sets the block of the compressor and the pump.
13. REGULAR
MAINTENANCE
Any cleaning operation is forbidden before disconnecting the unit from the
power supply.
Check for voltage before operating.
Periodic maintenance is essential to maintain the unit in perfect working order
under the functional as well as the energetic aspect.
Therefore it is essential to provide yearly controls for the:
13.6.1. Hydraulic circuit
CONTROL:
−
Water circuit filling
−
Water filter cleaning
−
Flow switch control
−
Air in the circuit (leaks)
−
That the water flow rate to the evaporator is always constant
−
The hydraulic piping thermal insulation state
−
Where provided the percentage of glycol
13.6.2. Electric circuit
CONTROL:
−
Efficiency of safety devices
−
Electrical power supply
−
Electrical power consumption
−
Connections tightened
−
Compressor casing heater
operation
13.6.3. Cooling circuit
CONTROL:
−
Compressor conditions
−
Efficiency of the tube core exchanger heater
−
Working pressure
−
Loss test for the control of the the cooling circuit sealing
−
High and low pressure switches operation
−
Perform the necessary checks on the filter-drier to verify their
efficiency.
13.6.4. Mechanical controls
CONTROL:
−
The screws, compressors and the electric box of the unit external panelling
are properly tightened. If they are poorly tightened, they produce abnormal
noise and vibrations
−
The structure conditions.
If necessary, treat oxidised parts with paints suitable for eliminating or
reducing oxidation.
14. EXTRAORDINARY
MAINTENANCE
The NXW are loaded with R410A gas and tested in the factory. In nor-
mal conditions, no Technical Assistance Service operation is needed
for the refrigerant gas check. In the long run, however, small leaks from
the joints may arise. Due to these leaks, the refrigerant comes out and
the circuit is drained, causing the unit to malfunction. In these cases,
the refrigerant leakage points are found and repaired, and the cooling
circuit is recharged, operating in compliance with Law 28 December
1993 no. 549.
14.6.1. Loading procedure
The loading procedure is as follows:
−
Empty and dehydrate the entire cooling circuit using a vacuum pump
connected to both the low and high pressure test points, until the vacuum
gauge reads about 10 Pa. Wait some minutes and check that this value
does not go back again over 50 Pa.
−
Connect the refrigerant gas bomb or a load cylinder to the grip on the low-
pressure line.
−
Charge the amount of refrigerant gas indicated on the characteristics plate
of the machine.
−
After any operation control that the liquid indicator indicates a dry circuit
(dry-green) In case of partial loss the circuit has to be emptied completely
before reloading it.
−
The refrigerant R410A has to be loaded only in liquid phase.
−
Different operating conditions from the normal can result in different
values.
−
Leak testing or leaking research must be carried out only by using
refrigerant gas R410A by checking with a suitable leak detection.
−
It is prohibited to use oxygen or acetylene or other flammable or
poisonous gas in the cooling circuit, because they can cause explosions or
intoxication.
