49
Aermec cod. 5806715_00 12.01
NRP 0200-0750
EN
ATTENTION
Commissioning must be performed
with standard settings. Only when
the inspection has been completed
can the functioning Set Point
values be changed.
Before start-up, power the unit for
at least 12-24 hours positioning
the protection magnet circuit
breaker switch and the door lock
isolating switch at ON.
Make sure that the control
panel is off in order to allow the
compressor oil sump to heat.
ATTENTION
11
This anti-freeze set
temperature can only be
varied by an authorised after-
sales centre and only after
having checked that there
is anti-freeze solution in the
water system.
12
Whenever this alarm
intervenes, call the
nearest after-sales service
immediately.
27.4.1. WITH THE MACHINE ON, CHECK
COOLING CIRCUIT
CHECK:
- That the compressor input current is lower than the
maximum indicated in the technical data table.
- That in models with three-phase power supply, the
compressor noise level is not abnormal. If this is the
case, invert a phase.
- 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%.
- The presence of any refrigerant GAS leaks
par cularly with reference to pressure gauge,
pressure transducers and pressure switches plugs.
(VIBRATIONS DURING TRANSPORTATION MAY
LOOSEN CONNECTIONS).
- Overheating.
Comparing the temperature read using a contact
thermostat positioned on the compressor intake
with the temperature shown on the low pressure
gauge (saturation temperature corresponding to
the evaporation pressure). The difference between
these two temperatures gives the overheating
value. Optimal values are between 4 and 8°C.
- Pressing line temperature If the subcooling and
overheating values are regular, the temperature
measured in the pressing line pipe at the outlet
of the compressor must be 30/40°C above the
condensation temperature.
CONTROL AND SAFETY DEVICES
CHECK
:
-
The manually reset high pressure switch.
That stops the compressor, generating the
respective alarm, when the flow pressure exceeds
the setpoint value. The control of its correct
functioning can be performed by closing the air
intake to the exchanger (in cooling mode) and
keeping the high pressure manometer under
control, check the intervention in correspondence
of the calibration value. Attention: In the event of
failure to intervene at the calibration value, stop the
compressor immediately and check the cause. The
reset is manual and can only be performed when
the pressure falls below the differential value (For
the set and differential values, consult the technical
manual).
- The anti-freeze control
The anti-freeze control managed by the electronic
regulation and by the temperature probe located
at the outlet of the evaporator is to prevent the
formation of ice when the water flow rate is
too low. Correct operation can be checked by
progressively increasingly the anti-freeze set-point
until it passes the outlet water temperature and
keeping the water temperature controlled with a
high precision thermometer, verify that the unit is
off and generates the respective alarm. After this
operation, take the antifreeze setpoint back to its
original value.
30. FUNCTIONING FEATURES
30.1. SET
POINT IN COOLING MODE
(Factory set) = 7°C,
∆
t = 5°C.
30.2. SET POINT IN HEATING MODE
(Factory set) = 45°C,
∆
t = 5°C.
If the unit power supply is restored a er a temporary
interrup on, the set mode will be kept in the memory.
30.3. COMPRESSOR START UP DELAY
Two func ons have been prepared to prevent
compressor start-ups that are too close.
- Minimum time from last switch-off 60 seconds in
cooling mode.
- Minimum time from last switch-on 300 seconds in
heating mode.
30.4. CIRCULATION PUMPS
NOT SUPPLIED
The circuit board envisions outputs for the
management of the circula on pumps.
The pump side u li es start immediately a er the
fi
rst
30 seconds of func oning. When the water
fl
ow rate
has gone into normal working condi ons, the
fl
ow
meter control func ons are ac vated (if envisioned).
Below
fi
nd the compressor start-up procedure, by
switching the source side pump on with
fl
ow meter
check if enabled a er 20 seconds.
Whenever alarms do not occur, the compressor starts.
30.5. ANTI FREEZE ALARM
The an -freeze alarm is ac ve if the machine is o
ff
or in stand-by mode. In order to prevent the heat
exchanger from breaking due to the water it contains
freezing, envision compressor block (if the machine
is on below 3.5°C) and igni on of the resistance (if
standby below 5°C). If the temperature detected by the
probe posi oned in output of the heat exchanger and
in inlet to the chiller is less than +3.8°C.
The interven on of this alarm determines
compressor block and not pump block, which remains
ac ve along with the switch-on of the resistance if
installed.
To restore normal func ons the temperature of the
outlet water must rise above +4°C. Rearm is manual.
30.6. WATER FLOW RATE ALARM
The unit manages a water
fl
ow rate alarm controlled
by a pressure switch or
fl
ow switch installed as
per standard on the machine. This type of safety
device intervenes a er the
fi
rst 30 seconds of pump
func oning, if the water
fl
ow rate is not su
ffi
cient.
The interven on of this alarm determines compressor
and pump block.