York Millennium YCAS 310, Установка, эксплуатация и обслуживание

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YORK INTERNATIONAL
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occurs after a two minute start-up timer has elapsed
from when power is re-applied.
Flow Switch Open:
Closure of the flow switch(es) is monitored to check
that flow is present in the evaporator when a
compressoris running. Any external cycling devices in-
stalled by the customer are also connected in series
with the flow switch(es). YCAS 2 system chillers have
a single flow switch wired to the control panel. YCAS 3
system chillers have two flow switches mounted to-
gether with one wired to each control panel. YDAS chiller
have two flow switches, one mounted in the flow from
each evaporator and wired to the associated control
panel. If the flow switch opens, all systems controlled
by the panel it is connected to will shut down and a NO
RUN PERM (Permissive) message is displayed. Clos-
ing of the flow switch, when flow is present, will cause
the message to disappear and auto-restart to occur.
CAUTION: Never bypass a flow switch. This will
cause damage to the chiller and void
any warranties.
2.5 SYSTEM FAULT STATUS MESSAGES
A System Fault will shut the affected system down
whenever a preset safety threshold is exceeded. Auto-
matic restart will occur after the first 2 shutdowns when
the anti-recycle timer times out and temperature de-
mand exists. After any combination of 3 Manual Reset
Safeties in a 90 minute time period, the affected sys-
tem will shut down and lock out. When one or more
systems are shut down on one of these safeties, a
message will appear on the Status display informing
the operator of the problem.
NOTE: 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 (see Section 1.8 for location of switches).
CAUTION: Before returning a locked out system to ser-
vice, a thorough investigation of the cause
of the fault should be made. Failure to re-
pair the cause of the fault while manually
allowing repetitive restarts may cause fur-
ther expensive damage to the system.
High Discharge Pressure Cutout:
The Discharge Pressure Safety prevents system pres-
sure from exceeding safe working limits. This safety is
a backup for the mechanical High Pressure Cutout in
the system. The Discharge Pressure Safety is program-
mable for a range of values below the system upper
limit (see Section 8.2, High Discharge Pressure Cut-
out for more details, page 40).
High Discharge Temperature Cutout:
This safety 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 separator.
The compressor will not start, or, in the first five sec-
onds of operation, will shut down if the discharge tem-
perature exceeds 225°F. After five seconds of opera-
tion, a warning message will be displayed if discharge
temperature exceeds 225°F. The compressor will shut
down if the discharge temperature exceeds 230°F .
High Oil Differential Pressure Cutout:
The High Oil Pressure Differential Safety protects the
compressors against loss of proper lubrication due to
oil return line blockage. The “differential oil pressure”
for this safety is computed by measuring discharge (oil
separator) pressure and subtracting oil pressure return-
ing to the compressor (Discharge – Oil = Oil PSID). Un-
der typical operation, the oil pressure differential dis-
play will read less than 25 PSID. 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 shut down.
This safety is activated after three minutes of opera-
tion. Oil pressure must be less than 45 PSID for R22
models or 40 PSID for R134a models for as long as
the compressor continues to run.
Low Oil Differential Pressure Cutout:
The Low Oil Pressure Differential Safety assures the
compressor receives proper lubrication by monitoring
the differential between oil pressure returning to the
compressor and suction pressure. Lack of a differen-
tial indicates that the compressor is not pumping and
no oil is being pumped through the compressor to lu-
bricate the bearings and rotors.
S Y S # N O R U N P E R M
S Y S # N O R U N P E R M
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 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 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