York YST Operation Manual page 134

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
" Warning – Condenser or evaporator xder
error"
The Evaporator pressure Transducer is indicating a
higher pressure than the Condenser Pressure Trans-
ducer after the chiller has been running for 10 minutes.
This is indicative of a Condenser or Evaporator Trans-
ducer failure. This message will be displayed until the
condition clears and the WARNING RESET Keypad
key is pressed in OPERATOR (or higher) access mode.
Condition not checked in Brine mode.
" Warning – refrigerant level out of range"
The output of the Subcooler Refrigerant Level Sensor
is > 5.1VDC. This is indicative of a Level Sensor fail-
ure. While this condition exists, the Subcooler Level
Control Valve is driven to the full open position. This
message automatically clears when the Refrigerant
Level sensor output is within range.
" Warning – Condenser – high pressure
limit"
The Condenser Pressure exceeds the High Pressure
Warning Setpoint threshold, programmed by a Service
technician logged in at SERVICE access level. This
message automatically clears when the Condenser
pressure decreases to 5 PSIG below the Setpoint.
"Warning - Mpu failure"
The difference between MPU#1 and MPU#2 analog
input signals is greater than 3% and generally indicates
a defective magnetic pickup or frequency to analog
converter. The panel logic selects the higher of the two
analog input signals for the speed control algorithm
and display, so a failure of one magnetic pickup will
not prevent the chiller from being started or operating.
This message will automatically clear when the mag-
netic pickup problem has been resolved.
" Warning - evaporator low pressure
override"
The evaporator pressure is below the setpoint of the
Evaporator Pressure Controller and the lower signal se-
lector relay is selecting its output to control the chiller
capacity. This message will automatically clear when
the evaporator pressure has returned to normal and the
Leaving Chilled Liquid Temperature Controller is con-
trolling the capacity of the chiller. Refer to the Capac-
ity Controls Screen descriptions for additional details.
134
" Warning - Condenser high pressure
override"
The condenser pressure is above the setpoint of the
Condenser Pressure Controller and the lower signal
selector relay is selecting its output to control the
chiller capacity. This message will automatically clear
when the condenser pressure has returned to normal
and the Leaving Chilled Liquid Temperature Controller
is controlling the capacity of the chiller. Refer to the
Capacity Controls Screen descriptions for additional
details.
" Warning - Turbine power limiter override"
Depending on the MSSP8-Power Limiting Mode
setpoint on Capacity Control Setpoints Screen 1, the
capacity of the chiller is being limited by either the
Governor Valve Position Limit Controller or the Tur-
bine Horsepower Limit Controller to control the tur-
bine power output. This message will automatically
clear when the load returns to normal and the Leaving
Chilled Liquid Temperature Controller is controlling
the capacity of the chiller. Refer to the Capacity Con-
trols Screen descriptions for additional details.
" Warning – automatic Capacity Control is not
available"
The chiller is running with all capacity control devices
in the Manual mode.
" Warning – hotwell Condensate low level"
The condensate level in the steam condenser hotwell
has been below the low-level switch actuation point
causing the input to the Digital I/O Expansion Board
to be open for 5 continuous seconds. This message
will automatically clear when the level rises above the
actuation point of the switch closing the input to the
Digital I/O Expansion Board.
" Warning – hotwell Condensate high level"
The condensate level in the steam condenser hotwell
has been above the high-level switch actuation point
causing the input to the York I/O board to be open for
5 continuous seconds. This message will automatically
clear when the level drops below the actuation point of
the switch closing the input to the York I/O board.
FORM 160.67-O1
ISSUE DATE: 4/1/2015
JOHNSON CONTROLS