NANO Precision NPC 015, Service Manual

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The data inside this manual are not binding and they can be modified by the manufacturer without notice. All rights reserved.
NPC 015 TO 230
C
HAPTER
10
T
ROUBLE SHOOTING
PROBLEM CAUSE SYMPTOM REMEDY
A
Tank water outlet
temperature
BTWOT
higher than the expected
value.
A1
Thermal load too high.
A1.1
Temperature BTWOT
greater than expected
value.
Restore the thermal load to
within the preset limits.
A2
Ambient temperature too
high.
A2.1
See A1.1
In the event of installation in a
closed place, if it is possible,
increase the change air flow
into the installation location, to
restore the ambient
temperature to within the
preset limits.
A3
Condenser fins are dirty.
A3.1
See A1.1
Clean the condenser fins.
A4
Front surface of the
condenser obstructed.
A4.1
See A1.1
Free the front surface of the
condenser.
A5
Lack of refrigerant in the
plant.
A5.1
• See A1.1 ;
• evaporating pressure too
low;
• a lot of bubbles in the liquid
indicator.
Get a refrigerator technician to
check for leaks and eliminate
them.
Fill the plant.
A6
Compressor protection
trips.
A6.1
• The head and the body of
the compressor are very
hot;
• the compressor stops and
try to start up again after
few seconds.
Get a refrigerator technician to
check for leaks and eliminate
them.
Fill the plant.
B
Low pressure drop (water
pressure) at pump outlet.
B1
Water flow too high.
Wrong working of the
pump (high flow, low
discharge head, high
absorption).
B1.1
• Possible increase in the
outlet temperature BTWOT
(see A1.1);
• with pump installed on the
machine: pressure
difference, read on the
machine pressure gauge,
too low with pump stopped
and pump running;
• possible tripping of pump
thermal protection.
Reduce water flow to within
the preset limits, for example
by closing partially a pump
outlet cock.
Reset the pump thermal
protection and check the
electrical absorption.
B2
See point C.
B2.1
See point C.
See point C.
B3
Evaporator obstructed
because of dirt transported
by the utilization water.
B3.1
High water temperature
difference between
input and outlet.
Depending on the type of dirt:
• clean the evaporator by
running a detergent
solution which is not
aggressive for steel,
aluminium and copper;
• run a high water flow
against the stream.
Install a filter upstream from
the unit.
C
Water differential pressure
switch FLOW alarm trips.
Alarm displayed:
A08
C1
The filter upstream from
the unit is obstructed, if
installed.
C1.1
• Water does not flow.
Pressure difference
between inlet and outlet
lower than 25mbar.
• Alarm displayed: A08.
• main alarm relay tripped.
Clean the upstream filter, if
installed.
Follow the alarm reset
procedure to star up the unit
again (chapter Electronic
Board).
C2
The pump is defective or
rotate in the wrong
direction. (three-phases
supply).
C2.1
• See C1.1 ;
• main alarm relay tripped.
Check the pump electrical
supply and, if it is necessary,
invert the two phases.
Follow the alarm reset
procedure to star up the unit
again (chapter Electronic
Board).
C3
Water inlet-outlet inverted
(units without hydraulic
kit).
C3.1
• See C1.1 ;
• main alarm relay tripped.
Invert the water inlet-outlet.
Follow the alarm reset
procedure to star up the unit
again (chapter Electronic
Board).