York OPTIVIEW - More MBC Safety Shutdowns

JOHNSON CONTROLS
128
FORM 160.78-O2
ISSUE DATE: 5/22/2017
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
MESSAGE DESCRIPTION
MBC – DSP WATCHDOG
This Safety Shutdown is set when the MBC determines a lapse in internal microproces-
sor activity through its Watchdog device. The MBC Watchdog Fault contacts open. The
MBC will not react to a levitation mode change command via serial comms. The MBC
remains in the levitation mode it was in when the fault occurred until power is removed.
Power is automatically removed when the VSD is stopped and the precharge command
ceases so the DS bus, which powers the MBC depletes. The chiller can be started when
the condition is released and the OptiView panel CLEAR FAULTS key is pressed.
MBC – EEPROM
This Safety Shutdown is set when a data discrepancy occurs with the EPROM on the AMB
control board. The MBC remains in Levitation mode with the motor shaft levitated until com-
manded to de-levitate over serial comms or VSD DC buss power depletes. This shutdown is
released when the board-level communication failure is resolved. The chiller can be started
when the condition is released and the OptiView panel CLEAR FAULTS key is pressed.
MBC – EXCESSIVE
SHUTDOWNS
This Safety Shutdown is set if 3 MBC Cycling Shutdowns occur in a 15 minute window.
It is released when all MBC faults clear. The 15 minute window begins with the rst
MBC fault. The chiller can be started when the condition is released and the OptiView
panel CLEAR FAULTS key is pressed.
MBC – FLASH MEMORY CLEAR
This Safety Shutdown is set when an internal problem occurs with the memory chip
on the AMB control board. The MBC remains in Levitation mode with the motor shaft
levitated until commanded to de-levitate over serial comms or VSD DC buss power
depletes. This shutdown is released when the board-level communication failure is re-
solved. The chiller can be started when the condition is released and the Optiview panel
CLEAR FAULTS key is pressed.
MBC – FLASH MEMORY WRITE
This Safety Shutdown is set when an internal problem occurs with the memory chip
on the AMB control board. The MBC remains in Levitation mode with the motor shaft
levitated until commanded to de-levitate over serial comms or VSD DC buss power
depletes. This shutdown is released when the board-level communication failure is re-
solved. The chiller can be started when the condition is released and the OptiView panel
CLEAR FAULTS key is pressed.
MBC – HIGH AMPLIFIER
TEMPERATURE
This Safety Shutdown is set when the MBC amplier temperature exceeds 176ºF (80ºC)
for 2 seconds continuous. The MBC ESD 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
amplier temperature drops 5.4ºF (3.1ºC) below the trip value. The chiller can be started
when the condition is released and the OptiView panel CLEAR FAULTS key is pressed.
MBC – HIGH BEARING
CURRENT
This Safety Shutdown is set when the MBC has determined any of the driveline Mag-
netic Bearing excitation currents exceeds the maximum Power Amplier rating, pro-
grammed at 4A, for 10 seconds continuous. The MBC ESD Fault contacts open. The
MBC remains in Levitation mode attempting to keep the motor shaft levitated until the
VSD rotation signal indicates greater than 10 Hz. This shutdown is released when all of
the bearing currents are less than 4A. The chiller can be started when the condition is
released and the OptiView panel CLEAR FAULTS key is pressed.
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 ESD Fault contacts open.
he 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
OptiView panel CLEAR FAULTS key is pressed.
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 ESD 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 OptiView panel CLEAR FAULTS key is pressed.
TABLE 9 - SAFETY SHUTDOWN MESSAGES (CONT'D)