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© STULZ S.p.A. – all rights reserved EN/06.2016/i09
WSA ExplOrEr OriginAl inStructiOnS
problem
possible cause
recommended action
Low press. group
X
Leaks of refrigerant in the circuit
X
Contact the Stulz service centre
Faulty low pressure switch of
X
circuit
Contact the Stulz service centre
Clogged filter-drier of the
X
circuit
Through the fluid level sight glass of the circuit
X
check for
moisture or bubbles in the refrigerant. Contact the Stulz
service centre
Partially closed tap on the fluid line of
X
circuit
Completely open the tap
Failure to the expansion valve of the
X
circuit
Contact the Stulz service centre
Frozen expansion valve of the x circuit
Check moisture through the fluid level sight glass of the
X
circuit Contact the Stulz service centre
Low flow of fluid to be cooled
Check the fluid level in the storage tank and, if necessary,
top up
Check for hydraulic circuit problems (failure of pumps,
closed taps...). Repair if necessary
High disch. temp.
X
Too high temperature of the compressor refrigerant flow
See the alarm “High press. group
X
”
Wrong calibration of the discharge temperature probe of the
X
circuit
Check with a reference thermometer. Contact the Stulz
service centre for re-calibration
High/max temperature
Insufficient cooling capacity compared to the thermal load
Reduce the thermal load or increase the number of chillers
Dirty filter of the fluid to be cooled
Clean the filter
Dirty evaporator
Contact the Stulz service centre
Poor calibration of the temperature probe on the water flow
Check with a reference thermometer. Contact the Stulz
service centre for re-calibration
Poor refrigerant charge on one or both circuits
Contact the Stulz service centre
Failure of one or more compressors
Check to see if other alarms appear on the display. Contact
the Stulz service centre
Low amount of fluid to be cooled
Check the fluid level in the storage tank and, if necessary,
top up
Low/min temperature
Low flow of fluid to be cooled
Check for hydraulic circuit problems (failure of pumps,
closed taps...). Repair if necessary
Poor calibration of the temperature probe on the water flow
Check with a reference thermometer. Contact the Stulz
service centre for re-calibration
Malfunction of the antifreeze heaters (optional)
Check and repair or replace
Inadequate fluid to be cooled to the minimum outdoor
temperature
Contact the Stulz service centre to defrost the evaporator.
Add glycol in the fluid to be cooled in a proportion suitable
for the outdoor temperature.
Evap. fluid flow
Low flow of fluid to be cooled
Check for hydraulic circuit problems (failure of pumps,
closed taps...). Repair if necessary
Air in the hydraulic circuit
Repair leaks, fill and vent the system
Failure of the differential pressure switch or of the flow
gauge (optional)
Check and if needed repair the wiring or replace the
component
X
probe
X
temperature probe/wrong pressure calibration
Contact the Stulz service centre for re-calibration
X
temperature probe/ disconnected or faulty pressure
Reconnect or replace the probe
S13 comm. error
Abnormal communication between the electronic control
and the expansion board of I/O controls
Contact the Stulz service centre
S13 software version
The software version with which the expansion board of
I/O controls is programmed do not comply with that of the
control
Contact the Stulz service centre
Upd setup S13 failed
Error in writing a parameter on the expansion board of I/O
controls by the electronic control
Contact the Stulz service centre
Wrong phase
Lack of or too low voltage of one or more phases
Check and take appropriate measures to restore the power
supply to the limits permitted
Wrong phase sequence
Invert two phases in the connection of the main power
supply to the chiller
