Johnson Controls YORK YVAM 0350, Operation & Maintenance Manual

Page: 104 / 162

Table 92: Safety shutdown messages
Message Description
MBC – DSP
WATCHDOG
This Safety Shutdown is set when the MBC determines a lapse in internal microprocessor activity on
the Control Board through its Watchdog device. The MBC Fault contacts open. The MBC does not
react to a levitation mode change command through serial comms. The MBC remains in the levitation
mode it was in when the fault occurred until power is removed. Power must be removed from the
UPS to the MBC. The chiller can be started when the condition is released and the Clear Faults button
is pressed on the OptiView panel.
MBC – EXCESSIVE
SHUTDOWNS
This Safety Shutdown is set if three MBC Cycling Shutdowns occur in a 15 minute window. It is
released when the chiller is stopped. The 15 minute window begins with the first MBC fault. The
chiller can be started when the condition is released and the Clear Faults button is pressed on the
OptiView panel.
MBC – HIGH
AMPLIFIER
TEMPERATURE
This Safety Shutdown is set when the MBC amplifier temperature exceeds 158°F (70°C) for 1 seconds
continuous. The MBC Fault contacts open. The MBC remains in Levitation mode with the motor
shaft levitated until the VSD rotation signal indicates less than 10 Hz. Then the MBC de-levitates the
rotor. The shutdown is released when amplifier temperature drops below the trip value. Check the
connection of the board to the heatsink and the response of the temperature sensor on the board.
The chiller can be started when the condition is released and the Clear Faults button is pressed on
the OptiView panel.
MBC – HIGH
BEARING Z1
TEMPERATURE
This Safety Shutdown is set when the MBC detects a temperature is greater than 266ºF (130ºC) on the
impeller end axial magnetic bearing. The MBC Fault contacts open. The MBC remains in Levitation
mode with the motor shaft levitated until the VSD rotation signal indicates is less than 10 Hz. This
shutdown is released when temperature is less than 266ºF (130ºC). The chiller can be started when
the condition is released and the Clear Faults button is pressed on the OptiView panel.
MBC – HIGH
BEARING Z2
TEMPERATURE
This Safety Shutdown is set when the MBC detects a temperature is greater than 266ºF (130ºC) on
the opposite-impeller end axial magnetic bearing. The MBC Fault contacts open. The MBC remains in
Levitation mode with the motor shaft levitated until the VSD rotation signal indicates is less than 10
Hz. This shutdown is released when temperature is less than 266ºF (130ºC). The chiller can be started
when the condition is released and the Clear Faults button is pressed on the OptiView panel.
MBC – HIGH INPUT
VOLTAGE
The main DC supply voltage to the MBC exceeded 165 VDC (150+ 10%).
MBC – NO
LEVITATION
This Safety Shutdown is set when OptiView software is commanding MBC Levitation Mode ON but the
MBC is not reporting Levitated within 15 seconds. This fault is prohibited when the MBC Alive input is
not high, indicating the MBC unavailable. This fault is released when the chiller is stopped. The chiller
can be started when the condition is released and the Clear Faults button is pressed on the OptiView
panel.
WARNING – MBC
– HIGH RADIAL
OSCILLATOR
VOLTAGE
This Safety Shutdown is set when the internal oscillator that drives the radial position sensor coil is
overloaded for one continuous second. This is generally the result of an open in the connection to the
shaft position sensor. It can also be a failure of the MBC control board. The MBC Fault contacts open.
The shutdown is released when the oscillator voltage drop is normal. The chiller can be started when
the condition is released and the Clear Faults button is pressed on the OptiView panel.
MBC – LOW RADIAL
OSCILLATOR
VOLTAGE
This Safety Shutdown is set when the internal oscillator that drives the radial position sensor coil is
low for one continuous second. This is generally the result of a short in the connection to the shaft
position sensor. It can also be a failure of the MBC control board. The MBC Fault contacts open. The
shutdown is released when the oscillator voltage drop is normal. The chiller can be started when the
condition is released and the Clear Faults button is pressed on the OptiView panel.
MBC – HIGH AXIAL
OSCILLATOR
VOLTAGE
This Safety Shutdown is set when the internal oscillator that drives the axial position sensor coil is
overloaded for one continuous second. This is generally the result of an open in the connection to the
shaft position sensor. It can also be a failure of the MBC control board. The MBC Fault contacts open.
The shutdown is released when the oscillator voltage drop is normal. The chiller can be started when
the condition is released and the Clear Faults button is pressed on the OptiView panel.
MBC – LOW AXIAL
OSCILLATOR
VOLTAGE
This Safety Shutdown is set when the internal oscillator that drives the axial position sensor coil is
low for one continuous second. This is generally the result of a short in the connection to the shaft
position sensor. It can also be a failure of the MBC control board. The MBC Fault contacts open. The
shutdown is released when the oscillator voltage drop is normal. The chiller can be started when the
condition is released and the Clear Faults button is pressed on the OptiView panel.
YVAM Control Center 104