Johnson Controls YORK YVAM 0350, Operation & Maintenance Manual

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Table 92: Safety shutdown messages
Message Description
MBC – OVERSPEED
FAULT
This Safety Shutdown is set when the MBC determines the rotor speed exceeds the programmed
setpoint of 360 Hz for 0.1 seconds continuous. Rotor speed is transmitted to the MBC from the VSD.
The MBC Fault contacts open. The MBC remains in Levitation mode with the motor shaft levitated
until commanded to de-levitate over serial comms. This shutdown is released when the speed signal
no longer exceeds the setpoint, which occurs 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.
MBC – POWER FAIL
LANDING
This Safety Shutdown is set when the panel boots up after a power loss has occurred and the buffer
data before the shutdown showed motor speed > 0, indicating the motor was rotating when the
UPS power was lost. If the Power Fail Landing Counter on the MBC Details Screen is < 5, the chiller
can be restarted after the cause of a loss of UPS power is determined and remedied and the Clear
Faults button is pressed on the OptiView panel. If the Power Fail Landing Counter is => 5, lockout
occurs and must be reset by a service technician according to the procedure in the Calibration and
Troubleshooting section of Form 160.88-M2 .
MBC – ROTOR
CONTRACTION
This Safety Shutdown is set when the MBC has calculated the algebraic difference between the
displacement at shaft impeller end axial position sensor and the shaft opposite-impeller end axial
position sensor is less than -100 µm (-100 micron). The MBC fault contacts open. The MBC remains
in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms.
This shutdown is released when the difference in displacements is over -100 µm (-100 micron). The
chiller can be started when the condition is released and the Clear Faults button is pressed on the
OptiView panel.
MBC – ROTOR
ELONGATION
This Safety Shutdown is set when the MBC has calculated the algebraic difference between the
displacement at shaft impeller end axial position sensor and the shaft opposite-impeller end axial
position sensor is greater than 700 µm (700 micron). The MBC Fault contacts open. The MBC remains
in Levitation mode with the motor shaft levitated until commanded to de-levitate over serial comms.
This shutdown is released when the difference in displacements no longer exceeds 700 µm (700
micron). The chiller can be started when the condition is released and the Clear Faults button is
pressed on the OptiView panel.
MBC – SPEED
SIGNAL FAULT
This Safety Shutdown is set when the MBC has the speed signal cycling fault three times in a 90-
minute window. The window is started when not currently in a window and a MBC Speed Signal
cycling fault is received. The MBC Fault contacts open. The MBC remains in Levitation mode with the
motor shaft levitated until commanded to de-levitate over serial comms. This shutdown is released
when a valid speed signal over 10 Hz is presented or the MBC is not in Rotation mode. The chiller
can be started when the condition is released and the Clear Faults button is pressed on the OptiView
panel.
SAFETY STOP
This is set when the panel safety stop hardware pushbutton is depressed, removing input from
the I/O Board terminal TB3-28 for > 500 msec. continuous. It also sets the local command to STOP.
The chiller can be started when the button is released and the Clear Faults button is pressed on the
OptiView panel.
MBC – STARTUP
FAILURE
This Safety Shutdown is set when the chiller initiates three MBC-STARTUP FAILURE Cycling Shutdown
in a 90 minute period. Refer to YORK YVAM Service Manual (Form 160.88-M2) for conditions necessary to
complete MBC startup successfully. Check fault history details to determine which specific conditions
were not met.
MBC – SPV
UNAUTHORIZED
ROTATION
This Safety Shutdown is set when the MBC is commanded to Rotation mode while it is not indicating
acceptable to rotate. The MBC Fault contacts open. The MBC remains in Levitation mode with the
motor shaft levitated until commanded to de-levitate over serial comms. This shutdown is the
rotation mode command is coincident with MBC levitated and rotation allowed contacts closed. The
chiller can be started when the condition is released and the Clear Faults button is pressed on the
OptiView panel.
MBC – DSP
UNAUTHORIZED
ROTATION
This Safety Shutdown is set when the MBC detects a rotor speed signal from the VSD while the
Levitation Mode is not activated. The MBC Fault contacts open. The MBC remains in Levitation mode
with the motor shaft levitated until commanded to de-levitate over serial comms. This shutdown is
released when the MBC Levitation or Rotation mode is activated or the VSD speed signal indicates no
shaft rotation. The chiller can be started when the condition is released and the Clear Faults button is
pressed on the OptiView panel.
105 YVAM Control Center