Troubleshooting - TEXA EMO Series Installation, Operation And Maintenance Manual

tact with one another and are treated sepa rately.
The compressor (CP) compresses the refrig­
erant and takes it to a high pressure and high
tempera ture. The compressor then pushes the
refrigerant through a heat ex changer coil, called
condenser (C), where it is cooled by am bient air
thus passing from the gas to the liquid state. At
the liquid state it then passes through the capil­
lary (EXP) and as it is at a much lower pressure,
nebulizes at the out let. It is then re ceived by the
heat exchanger coil, called evaporator (E), by
means of which it ab sorbs heat from the enclo­
sure air and passes from a liquid state to gas.
The enclosure is cooled down in this manner.
The gas is then drawn back into the compressor
and the above de scribed cycle is re peated.
11.2 Safety devices.
The refrigeration circuit is fitted with a high pres­
sure safety switch HP (figure F.12) set at maxi­
mum cooling unit working pressure. If the thresh­
old is exceeded, the pressure switch stops the
com pressor working. It is the auto matically re­

12. Troubleshooting

Malfunction Conditions
It fails to cool The internal fan works, the external fan and com­
pressor do not work.
No component works
Compressor, external and internal fan work
Compressor and external fan work, internal fan
does not work
External and internal fan work, compressor does
not work
It is not cooling enough External and internal fans work, compressor works
all the time
Inside fan works, external fan and compressor
work irregularly
External and internal fans work, compressor works
irregularly
Too much condensate forming Enclosure door open
Enclosure door closed
settable type. The low pressure safety switch LP
stop the compressor when the suction pressure
decrease under the fixed threshold. Also the low
pressure safety switch is automatucally resetta­
ble. The fans and com pressor have a thermal
cut­out switch inside that stops them in the case
of anomalous over temperatures. A condensa­
tion control pressure switch (FSD) is mounted
on condenser fan; it controls the condenser fan
speed to keep the condensing temperature con­
stant.
11.3 Disposal.
Caution! The cooling unit contains R134a (or
R407C) re frigerant and small quantities of
lubricating oil. These substances pollute and
must not be dumped. Replacement, repairs and
final dis posal must be seen to by experts.
NOTE
Keep the documentation in a dry place.
Causes
The temperature inside the enclosure is lower than what
is set on the adjustment thermostat.
The adjustment thermostat has failed
No electricity getting to the unit.
Cooling unit empty of fluid
Compressor mechanical failure
Internal fan capacitor failed
Internal fan failed
Compressor's amperometric protector failed (external to
the compressor, where present)
Relay or PTC for compressor starting failed
Capacitor for compressor starting failed (where present)
Compressor motor electrical failure
High pressure safety switch failed
Compressor contactor failed (where present)
Cooling unit under sized for the heat dissipated inside
the enclosure
Insufficient gas in the cooling unit
Thermostat set point incorrect
High pressure safety switch triggered:
• Ambient temperature over the maximum work­
ing limit
•
Heat exchanger coil (condenser) either dirty or
clogged
Thermal protector inside the compressor triggered:
•
Ambient temperature over the maximum work­
ing limit
•
Heat exchanger coil (condenser) either dirty or
clogged
Too much ambient air inside the enclosure
Enclosure protection level is below IP54
The enclosure/cooling unit connecting seal has been
fitted incorrectly
5
Remedy
This is not a malfunction of the cooling unit. To verify functioning
when testing, lower the thermostat setting until the compressor and
external fan start working and then reset the thermostat.
Change the adjustment thermostat
This is not a malfunction of the cooling unit.
• Make sure the power cable has been connected well to the
terminals.
•
Check that the cubicle doors and switches are closed
Call a refrigeration expert or the Manufacturer's Technical Assist­
ance Service
Call a refrigeration expert or the Manufacturer's Technical Assist­
ance Service
Change the internal fan's capacitor
Change the internal fan
Change the amperometric protector
Change the relay or PTC for compressor starting
Change the capacitor for compressor starting
Call a refrigeration expert or the Manufacturer's Technical Assist­
ance Service
Call a refrigeration expert or the Manufacturer's Technical Assist­
ance Service
Change the contactor
Change the cooling unit with another of greater capacity
Call a refrigeration expert or the Manufacturer's Technical Assist­
ance Service
Check thermostat setpoint
• Ventilate the premises where the enclosure is installed to keep
ambient temperature lower.
•
Clean the exchanger with compressed air and detergent
•
Ventilate the premises where the enclosure is installed to keep
ambient temperature lower.
•
Clean the coil with compressed air and detergent
This is not a malfunction of the cooling unit. Close the enclosure
door or disable the cooling unit
This is not a malfunction of the cooling unit. Seal enclosure open­
ings, e.g. for passage and upward path of wires
Check seal and remedy