York YCWS0313SC, Инструкция по установке, эксплуатации и обслуживанию, Страница: 49 / 104

FORM 201.24-NM2
49
YORK INTERNATIONAL
Never bypass a flow switch. This will
cause damage to the chiller and void
any warranties.
3.6 SYSTEM FAULT STATUS MESSAGES
System faults will shut the affected system down when-
ever a pre-set safety threshold is exceeded for 3 sec-
onds. Automatic restart will occur after the first 2 shut-
downs when the anti-recycle timer times out and tem-
perature demand exists.
After any combination of 3 Manual Reset Safeties in a
90 minute period, the affected system will shutdown
and lock out on the last fault. When one or more sys-
tems are shutdown on one of these safeties, a message
will appear on the ‘STATUS’ display informing the op-
erator of the problem.
The High Motor Current Safety is a
unique safety which will lock-out a
system after only a single fault.
To reset a locked-out system, turn the system switch
for the affected system to the ‘OFF’ position, then back
to the ‘ON’ position.
Before returning a locked-out system
to service, a thorough investigation of
the cause of the fault should be made.
Failure to repair the cause of the fault
while manually allowing repetitive re-
starts may cause further damage to the
system.
High Discharge Pressure Cutout:
This cutout prevents system pressure from exceeding
safe working limits. This safety is a backup for the me-
chanical High Pressure Cutout in each system.
The cutout is programmable for a range of values be-
low the system upper limit.
High Discharge Temperature Cutout:
This cutout protects the compressor rotors from dam-
age due to overheating, expansion, and breakdown of
the oil film seal between the rotors. It also protects
against excessive oil temperature in the discharge oil
separator.
For the first 4 seconds of operation discharge tempera-
ture is ignored. After 4 seconds of operation the com-
pressor will shutdown if the discharge temperature ex-
ceeds 127°C.
High Oil Differential Pressure Cutout:
This cutout protects the compressors against loss of
proper lubrication due to oil return line blockage.
The ‘differential oil pressure’ for this cutout is calcu-
lated by measuring discharge (oil separator) pressure
and subtracting oil pressure returning to the compres-
sor (Discharge - Oil = Oil bar D).
Under typical operation, the oil pressure differential dis-
play will read less than 1.7 bar. If oil pressure at the
compressor drops due to filter blockage, the differential
pressure on the display will increase and when the maxi-
mum limit is reached the compressor will be shutdown.
This cutout is activated after 3 minutes of operation.
Oil pressure must be less than 4.4 bar as long as the
compressor continues to run.
Low Oil Differential Pressure Cutout:
The cutout assures the compressor receives proper lu-
brication by monitoring the differential between oil pres-
sure returning to the compressor and suction pressure.
Lack of a differential indicates that the compressor is
not pumping or low condenser pressure and no oil is
being pumped through the compressor to lubricate the
bearings and rotors.
This type of oil failure will not be picked up by the
High Oil Differential Safety since no flow will cause
the differential through the oil piping to drop to zero.
S Y S # H I G H D S C H T E M P
S Y S # H I G H D S C H T E M P
S Y S # H I G H D S C H P R E S
S Y S # H I G H D S C H P R E S
S Y S # H I G H O I L D I F F
S Y S # H I G H O I L D I F F
S Y S # L O W O I L D I F F
S Y S # L O W O I L D I F F
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