EWWD440~850AAYNNO**
Packaged water-cooled water chillers
4PW25558-1B
Installation and operation manual
33
T
ROUBLESHOOTING
This section provides useful information for diagnosing and
correcting certain troubles which may occur in the unit.
Following cases do not represent an abnormality
Before starting the troubleshooting procedure, carry out a thorough
visual inspection of the unit and look for obvious defects such as
loose connections or defective wiring.
Before contacting your local dealer, read this chapter carefully, it will
save you time and money.
When a safety device was activated, stop the unit and find out why
the safety device was activated before resetting it. Under no
circumstances safety devices may be bridged or changed to a value
other than the factory setting. If the cause of the problem cannot be
found, call your local dealer.
Symptom 1: Pump and compressor do not start at all
Symptom 2: Pump starts but water does not circulate
Symptom 3: Pump starts but compressor does not start
Symptom 4: Water outlet temperature is extremely low or high
Symptom 5: Compressor stops while operating and does not start
automatically
Symptom 6: Remote operation is not available
Symptom 7: Although chilled water temperature is high, one side
compressor only starts
S
YMPTOM
P
OSSIBILE
CAUSES
While stop, compressor is hot.
(Chiller electrified)
Because oil heater is electrified to
warm up compressor for the purpose
of smoothing starting of unit, this is
not abnormality.
When the unit is operating under low
load condition, refrigerant passage
sound is heard from liquid piping
section.
This is because a slight quantity of
refrigerant gas flows from the
condenser to the evaporator under
partial load operation. This is not
abnormality.
When carrying out an inspection on the supply panel or on
the switch box of the unit, always make sure that the circuit
breaker of the unit is switched off.
P
OSSIBILE
CAUSES
C
ORRECTIVE
ACTION
Power failure
For reason of safety, turn OFF power
switch once.
Power switch OFF
Turn ON power switch.
Power fuse burned
Replace power fuse.
Defective bridge wiring between unit
and pump
Check respective bridge wiring of
pump operation command and
interlock signal for omission of
connection and defective contact.
Defective input of operation
command
Check bridge wiring of remote
operation command for omission of
connection and defective
connection.
When instantaneous signal is used,
arrange pulse width to be 200 msec
or more.
"LOCAL"/"REMOTE" of unit Run/
Stop has switched
Make selection "LOCAL" or
"REMOTE" in "OPERATION" screen
of the graphic panel display.
Especially if you cause the unit to
stop by "STOP" button on the switch
box during remote operation,
selection in control screen shifts
from "REMOTE" to "LOCAL"
automatically, so be careful.
P
OSSIBILE
CAUSES
C
ORRECTIVE
ACTION
Lack of water quantity of makeup
water
Pour makeup water sufficiently.
(Pumping is not performed unless
otherwise pump and suction pipe are
filled with water.)
Pump rotates in reverse direction
Correct the direction of rotation of
pump. (Make it to clockwise direction
viewed from motor side).
Valve in piping does not open
sufficiently
Open valve in piping sufficiently.
P
OSSIBILE
CAUSES
C
ORRECTIVE
ACTION
Defective interlock signal
Arrange in a manner that the
interlock signal is returned to the unit
within 180 seconds after input of
operation signal to the unit.
ON-OFF limiting
Compressor starts after ON-OFF
limiting time ends. (See
).
Thermo in stop
Compressor starts if thermo is reset.
(See
P
OSSIBILE
CAUSES
C
ORRECTIVE
ACTION
Water quantity regulating valve has
not opened
Open water quantity valve
moderately.
Input error of target temperature
setting
Input correct target temperature
(See
Erroneous input of operation mode
(Model with 2-temperature setting
option only)
Stop unit once then input correct
operation mode (See
It takes maximum 1 second from
time when unit accepts operation
mode signal to time when mode is
confirmed. Operation signal and
mode signal shall be input with time
difference.
P
OSSIBILE
CAUSES
C
ORRECTIVE
ACTION
Water quantity regulating valve has
not opened
Open water quantity regulating valve
moderately.
Differential set point between thermo
stop and thermo reset is big
Decrease differential set point (See
"Low load stop (Thermo off)" on
page 21
).
Compressor individual error is
occured (Pertinent compressor only
stops)
Check indication on details of error
on graphic panel display and then
contact your dealer.
P
OSSIBILE
CAUSES
C
ORRECTIVE
ACTION
Defective input of operation
command
Check bridge wiring of remote
operation command for omission of
connection and defective contact.
When you use instantaneous signal,
200 msec or more of pulse width is
required.
"LOCAL"/"REMOTE" of unit Run/
Stop has switched
Make selection "LOCAL" or
"REMOTE" in "OPERATION" screen
of the graphic panel display.
Especially if you cause the unit to
stop by "STOP" button on the switch
box during remote operation,
selection in control screen shifts
from "REMOTE" to "LOCAL"
automatically, so be careful.
P
OSSIBILE
CAUSES
C
ORRECTIVE
ACTION
"UNITS TO CONTROL" setting in
graphic panel display is set to
"1UNIT".
Change setting in the left to
"2UNITS". (See
starting order rotation function" on
page 24
)