21
18.03. 5719210_03
ANL / 290-650
EN
10. OPERATING CHARACTERISTICS
10.1. COOLING SETPOINT
(Factory default) = 7°C, ∆t = 5K.
10.2. COMPRESSOR DELAY TIMERS
To avoid excessive compressor starts two functions are
provided.
- Minimum time compressor is OFF 180 seconds.
- Minimum time compressor is ON 120 seconds.
10.3. CIRCULATING PUMPS
The wiring schematic provides outputs to control the
circulating pumps. The system pump starts immediate-
ly and after 40 seconds of operation, when the water
flow is stabilised, the pressure differential/flow switch
control function is enabled. If no alarms are present
the unit will start.
10.4. ANTI-FREEZE ALARM
The alarm
11
is always active even in standby mode.
To prevent damage to the plate heat exchanger by
freezing of the water within the unit is stopped and
an alarm raised if the water temperature drops below
the minimum anti-freeze setpoint of 3°C. The unit can
only re-start after a manual reset and if the anti-freeze
sensor reads a water temperature above 4°C
12
. With
the unit in off mode and with a water temperature
below 4°C the factory fitted electric heaters on the
heat exchanger are turned on, and turned off when
the water temperature exceeds 5°C. The water pump
always remains active.
10.5. WATER FLOW ALARM
The unit has a low water flow rate alarm using a fac-
tory fitted differential pressure switch or flow switch.
This safety activates after the first 40 seconds of pump
operation if the water flow rate is not sufficient. The
operation of this alarm stops the compressors and the
pump.
WARNING
11
The anti-freeze setpoint
can only be adjusted by an
authorised service centre and
only after verifying that the
hydraulic circuit has the cor-
rect % of anti-freeze solution.
12
If this alarm occurs immediate-
ly call the authorised technical
service assistance.
11. ROUTINE MAINTENANCE
It is forbidden to carry out any cleaning operation
before isolating from the power supply
1
.
Confirm no voltage is present before commencing
works.
Periodic maintenance is a fundamental requirement to
ensure efficient unit operation both in terms of opera-
tion and energy efficiency.
The fundamental required annual checks are:
11.1. HYDRAULIC CIRCUIT
CHECK:
1.
Water circuit is filled.
2.
Water filter is clean.
3.
Operation of the differential pressure or flow
switch.
4.
Absence of air in the system (vent).
5.
Water flow rate is always constant through the
evaporator.
6.
Condition of the hydraulic piping insulation.
7.
The percentage of anti-freeze liquid, as may be
required
11.2. ELECTRIC CIRCUIT
CHECK:
1.
Operation of safeties.
2.
Power supply voltage.
3.
Electrical power input.
4.
Tightness of connections and terminals.
5.
Operation of the compressor crankcase heater.
11.3. REFRIGERANT CIRCUIT
CHECK:
1.
State of compressors.
2.
Efficiency of the plate heat exchanger.
3.
Operating pressures.
4.
Leaks to confirm the correct operating refriger-
ant charge.
5.
Operation of the high and low pressure pres-
sostats
6.
Efficient operation of the filter drier.
11.4. MECHANICAL CHECKS
CHECK:
1.
Tightness of screws,
of compressors and electri-
cal panel and external panelling of the unit. Poor
fixings cause noise and abnormal vibrations.
2.
The state of the unit structure.
Treat any parts showing signs of corrosion with
the appropriate paints to reduce or eliminate
rust.
12. SPECIAL MAINTENANCE
The ANL units are factory charged with R410A and
tested. In normal operation they therefore do not
require any intervention from the technical assistance
service in relation to the refrigerant charge. Over time
some small leaks can appear, causing discharging the
circuit and causing a malfunction of the unit. In this
case the leaks have to be found and repaired and the
unit recharged in accordance and as required under
current legislation and good working practices.
13. DISPOSAL
Ensure that the disposal of the unit is carried out in
accordance with the current legal requirements.
WARNING
We recommend a service log book is
provided for the unit (responsibility
of the user) to keep records of any
works on the unit, which will aid
maintenance and repair works. Note
in the service log book date, type of
works (routine maintenance, inspec-
tion or repair), describing the event
and the measures taken.
WARNING
I
t is
FORBIDDEN
to charge with
refrigerant circuit with a refrigerant
type different to that indicated. Us-
ing a different refrigerant can cause
serious damage to the unit.
Summary of Contents for Variable Multi Flow ANL 290
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