York YK Style H Operation Manual page 183

FORM 160.76-O2
issue date: 6/15/2015
The imbalance is calculated as:
(Ia-Iave) + (Ib-Iave) + (Ic-Iave)
2(Iave)
The Style B Solid State Starter and Variable Speed
Drive detects the unbalance condition and advise the
OptiView Control Center Microboard via serial com-
munications. This safety shutdown is not performed on
Electro-Mechanical Starter applications.
Thrust Bearing – Proximity Probe Clearance
(Chillers with J or H3 compressors)
The clearance between the compressor high speed
thrust collar and the tip of the Proximity Probe has in-
creased more than +10 mils or decreased to less than
-25 mils (for 2 continuous seconds) from the Refer-
ence Position. The minimum allowed clearance is 23
mils. Therefore, if the Reference position is less than
47 mils, the shutdown will occur when the actual clear-
ance is less than 22 mils.
The clearance is only checked during the last 20 sec-
onds of System Prelube, during System Run and dur-
ing coastdown. Therefore, the fault is only detected
during those periods. Also, the +10 mil threshold must
be exceeded for 2 continuous seconds.
This shutdown must be evaluated by a
qualified Service Technician prior to
starting the chiller. Starting the chiller
without this evaluation could result in
severe compressor damage. To prevent the
chiller from starting without the proper
evaluation, restart is inhibited until the
clearance is within acceptable limits and a
special reset procedure is performed by the
Service Technician. The evaluation and
reset procedure are contained in Optiv-
iew Control Center - Service Instructions
(Form 160.76-M1).
Thrust Bearing – Proximity Probe Out Of Range
(Chillers with J or H3 compressors)
The clearance between the compressor high speed
thrust collar and the tip of the Proximity Probe has de-
creased to less than 17 mils.
The clearance is only checked during the last 20 sec-
onds of System Prelube, during System Run and dur-
ing coastdown. Therefore, the fault is only detected
during those periods.
JOHNSON CONTROLS
x 100
Thrust Bearing – Limit Switch Open
(Chillers with P, Q, G or H5-8 compressors)
The High Speed Thrust Bearing Limit Switch contacts,
connected to TB3-81, have opened. This occurs when
the Bearing position decreases to less than the allowed
position.
Watchdog – Software Reboot
The Microboard's software Watchdog initiated a Mi-
croprocessor reset because it detected that a portion of
the chiller operating program was not being executed.
The result of this reset is a safety shutdown and re-ini-
tialization of the program. This is generally indicative
of a severe electrical power disturbance or impending
Microboard Failure. The chiller can be started after the
Clear Fault key is pressed on the display.
Surge Protection – Excess Surge
(Applies only if Surge Protection Shutdown feature is
Enabled)
The Surge Window Count surge events exceeded the
Count Limit Setpoint. If the Surge Protection Extended
Run feature is Disabled, the chiller shuts down as soon
SECTION 3 - DISPLAY MESSAGES
This shutdown must be evaluated by a
qualified Service Technician prior to start-
ing the chiller. Starting the chiller without
this evaluation could result in severe
compressor damage. To prevent the chiller
from starting without the proper evalua-
tion, restart is inhibited until the clearance
is within +10 to -25 mils of the Reference
Position and a special reset procedure
is performed by the Service Technician.
The evaluation and reset procedure are
contained in OptiView Control Center -
Service Instructions (Form 160.76-M1).
This shutdown must be evaluated by a
qualified Service Technician prior to
starting the chiller. Starting the chiller
without this evaluation could result in
severe compressor damage. To prevent
the chiller from starting without the
proper evaluation, restart is inhibited
until the switch contacts have closed and
a special reset procedure is performed
by the Service Technician. The evalua-
tion and reset procedure are contained
in OptiView Control Center - Service
Instructions (Form 160.76-M1).
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