CO
2
NNEXT
rev.01
EN
116 / 293
POSSIBLE CAUSE
SOLUTI
F
Compressor works continuously or for long periods
x
System not sufficiently sized according to the
load.
x
Replace the system with a more powerful one.
x
Excessive load to cool or insufficient insulation
x
Reduce the load and improve insulation, if
possible.
x
Evaporator covered with ice.
x
Defrost.
x
Limited thermal exchange on clogged gas-
x
Check function of the gas-cooler
G
High pressure in main circuit supply
x
Gas-cooler malfunction
x
Clean and check the gas-cooler and the
relative fans
x
Check the temperature probes for the STH2
and STA gas cooler output
x
HPV high pressure valve not working properly.
x
Check valve check alarms and reset.
x
Check the
correct
operation of the HPV valve.
x
Check the minimum set-point.
x
Clean entire mechanism and filter if provided
for the HPV valve.
x
Replace the HPV valve.
H
High pressure liquid receiver
x
VFL gas
flash
valve
not
working
properly.
x
Check valve check alarms and reset.
x
Check the
correct
operation of the VFL valve.
x
Clean the entire mechanism and filter if
required of the VFL valve.
x
Replace the VFL valve.
x
Parallel compressor (if present).
x
Check set-point.
x
Check correct
compressor
operation, related alarms and reset
I
Frosted or wet drain pipes - low overheating
x
Thermostatic valve functioning.
x
Possible liquid return to the compressor. Check
thermostatic
valve
overheating and related parameters.
x
Expansion valve blocked in opening.
x
Clean the valve from foreign substances or
replace it if necessary.
x
Incorrect parameters for management of utilities
and/or related defrosts, utilities management
and defrost management.
x
Check the parameters and optimise them to
achieve overheating of at least 15K.
