Johnson Controls YORK YMC2 Operation And Maintenance Manual

Table 99: Cycling shutdown messages
Message Description
MBC SHUTDOWN –
REQUESTING FAULT
DATA
The MBC has shutdown the chiller and the control center has not
yet received the cause of the fault from the MBC via the serial
communications link. The MBC shuts down the chiller by opening the
MBC Fault contacts (located on the MBC control board and connected
to TB3-70 in the control center). The microboard in the control center
then sends a request for the cause of the fault to the MBC control
board over the serial link. Since serial communications are initiated
every 2 seconds, this message is typically displayed for a few seconds
and then replaced with one of the other MBC fault messages in this
section.
MBC – SPEED SIGNAL
FAULT
This Cycling Shutdown is set when the MBC looses the speed signal
that is expected from the VSD or speed signal is less than 10 Hz. While
the MBC is commanded in Rotation Mode. 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 is out of Rotation mode or speed
greater than 10 Hz is transmitted. A 10 second bypass exists when the
initial command to Rotation Mode occurs.
MBC – STARTUP
FAILURE
This Shutdown is set when the chiller fails to exit the MBC startup state
within 60 seconds, during a chiller start. Refer to the Basic Operation
section of YMC
2
Model B Service Manual (Form 160.84-M2) for conditions
necessary to complete MBC startup successfully. Check fault history
details to determine which specific conditions were not met.
MBC – V13
LOW FREQUENCY
DISPLACEMENT
The MBC has measured shaft displacement is greater than 90 micron
from center in the orthogonal radial axis designated V at the impeller
end radial magnetic bearing during Levitation or Rotation mode over
a 7 second window (approximately 2/3 of the air gap space to the
touchdown bearing). 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
displacement is less than 90 micron.
MBC - UNKNOWN
PARAMETER FILE
This Cycling shutdown is set when the bearing setup parameter file
received from Opti-View is not an expected file format. The fault is
released when the error is corrected. This fault could be corrupted data
transfer between OptiView and the MBC.
MBC – V13 POSITION
The MBC has measured shaft displacement is greater than 100 micron
from center in the orthogonal radial axis designated V at the impeller
end radial magnetic bearing during Levitation or Rotation mode
(approximately 2/3 of the air gap space to the touchdown bearing). 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 displacement is less than 100
micron.
YMC
2
Mod B with OptiView Control Center
104

Johnson Controls YORK YMC2 Specifications

General

Brand	Johnson Controls
Model	YORK YMC2
Category	Chiller
Language	English