York YST Operation Manual page 142

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
"Compr oil – high Temperature"
The oil temperature, as sensed by the Oil Temperature
Thermistor, has increased to > 180.0°F. The chiller can
be started after the temperature decreases to < 180.0°F
and the START/STOP control switch is placed in the
STOP-RESET (O) position.
" Compr oil – low differential pressure"
The differential oil pressure decreased to < 15.0 PSID
while the chiller was running or failed to achieve 25.0
PSID by the last 5 seconds of the "System Prelube" pe-
riod. The differential oil pressure is the difference be-
tween the output of the Sump Oil Pressure Transducer
(system low pressure) and the output of the Pump Oil
Pressure Transducer (system high pressure). The chill-
er can be started after the START/STOP control switch
is placed in the STOP-RESET (O) position.
" Compr oil - high differential pressure"
The differential oil Pressure increased to >120.0 PSID
while the oil pump was running. The differential oil
pressure is the difference between the output of the
Sump Oil Pressure Transducer (system low pressure)
and the output of the Pump Oil Pressure Transducer
(system high pressure). The chiller can be started after
the differential oil pressure decreases to <120.0 PSID
and the START/STOP control switch is placed in the
STOP-RESET (O) position.
" Compr oil – pump pressure Transducer out
of range"
The Pump Oil Pressure Transducer (system high pres-
sure) is indicating a pressure that is <0.0 PSIG or
>315.0 PSIG. This is outside the normal operating
range of the transducer. This generally indicates a de-
fective transducer. The chiller can be started after the
transducer is indicating a pressure that is within range
and the START/STOP control switch is placed in the
STOP-RESET (O) position.
" Compr oil – Sump pressure Transducer out
of range"
The Sump Oil Pressure Transducer (system low pres-
sure) is indicating a pressure that is outside the normal
operating range of the transducer as follows: R134a -
<0.0 PSIG or >315.0 PSIG, R22 - <23.2 PSIG or >271.8
PSIG. This generally indicates a defective transducer.
The chiller can be started after the transducer is indi-
cating a pressure that is within range and the START/
STOP control switch is placed in the STOP-RESET
(O) position.
142
" Compr oil - differential pressure
Calibration"
The Sump and Pump oil pressure Transducers indicated a dif-
ferential oil pressure of >15.0 PSID during the oil pressure
transducer Auto-Zeroing period that begins 10 seconds into
"System Pre-lube" and lasts for 3 seconds. This is indicative
of a defective Sump or Pump Transducer, since the oil pump
is not running during this period and the actual differential
oil pressure is 0 PSID. The transducers are sensing the same
pressure during this period and their outputs should be simi-
lar. The chiller can be started after the START/STOP control
switch is placed in the STOP-RESET (O) position.
" Compr oil – variable Speed pump – Setpoint
not achieved"
This is only applicable to chillers equipped with the
Oil Pump Variable Speed Drive. One of the following
conditions have occurred while in "System Prelube",
"System Run" or "System Coastdown". The chiller
can be started after the START/STOP control switch is
placed in the STOP-RESET (O) position.
1. The differential oil pressure was <35.0 PSID; for
5 continuous seconds during the last 10 seconds
of the "System Prelube" period or during the first
15 seconds of "System Run".
-OR-
2. Anytime after the first 30 seconds of "System
run", the differential oil pressure was < the Oil
Pressure Setpoint with the speed command from
the Microboard at 60 Hz for 5 continuous seconds.
"Compr Thrust bearing – proximity probe
Clearance"
The clearance between the compressor high speed
thrust collar and the tip of the Proximity Probe has
increased > +10 mils or decreased > -25 mils (for 2
continuous seconds) from the Reference Position. The
minimum allowed clearance is 23 mils. Therefore, if
the Reference position is <47 mils, the shutdown will
occur when the actual clearance is < 22 mils.
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.
FORM 160.67-O1
ISSUE DATE: 4/1/2015
JOHNSON CONTROLS