York OPTIVIEW - VSD Cycling Shutdowns

JOHNSON CONTROLS
121
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
FORM 160.78-O2
ISSUE DATE: 5/22/2017
2
MESSAGE DESCRIPTION
MBC – VW24 VIBRATION
The MBC has measured synchronous speed (rst harmonic) shaft vibration at the
opposite-impeller end radial magnetic bearing is greter than 60 µm from 0 to the peak
amplitude in Rotation mode. This condition is monitored only when the AVR and ABS
lter is on, which occurs for speed above 80 Hz. The MBC ESD Fault contacts open.
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 warning is released
when vibration is less than 60 µm.
MBC – Z12 LOW FREQUENCY
DISPLACEMENT
The MBC has measured shaft displacement is greater than 100 µm axially from the de-
sign running position over a 7 second window (approximately 1/3 of the air gap space to
the touchdown bearing axially). The MBC ESD Fault contacts open. 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 warning is released when displace-
ment is less than 100 µm.
MBC – Z12 POSITION
The MBC has measured shaft displacement is greater than 100 µm axially from the
design running position (approximately 1/2 of the air gap space to the touchdown bearing
axially). The MBC ESD Fault contacts open. 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 displacement is less than 100 µm.
MULTIUNIT CYCLING –
CONTACTS OPEN
The Multiunit Cycling contacts connected to I/O Board TB4-9, have opened to initiate a
cycling shutdown. If the chiller is running when this occurs, the Pre-rotation Vanes are
driven fully closed prior to shutting down the chiller. The chiller will automatically restart
when the contacts close.
SYSTEM CYCLING –
CONTACTS OPEN
The System Cycling contacts connected to I/O Board TB4-13, have opened to initiate a
cycling shutdown. If the chiller is running when this occurs, the Pre-rotation Vanes are
driven fully closed prior to shutting down the chiller. The chiller will automatically restart
when the contacts close.
VSD – DC BUS
PRE-REGULATION
The dc link voltage has not attained within +/-50 V of the dc link voltage setpoint dened
by the motor and line voltages (750V for YMC
2
) within 2 seconds after the boost recti-
er’s closed loop control has been enabled. The VSD logic board shall disable boost
rectier’s IGBT gating signals during this fault. The VSD logic board shall time 10 sec-
onds before clearing the fault and allowing another pre-charge to start. The VFD’s fan(s)
and water pump(s) shall remain energized during this time. The VSD logic board shall
allow up to three consecutive pre-charge-related or pre-regulation-related faults faults to
occur. After the third consecutive pre-charge-related fault, Safety Shutdown message
“VSD – DC BUS PRE-REGULATION LOCKOUT” is generated.
VSD – HIGH DC BUS VOLTAGE
The VSD’s DC link voltage is continuously monitored and if the level exceeds 878VDC,
± 28VDC a Bus Over-Voltage shutdown is initiated. If this shutdown occurs, it will be
necessary to look at the level of the 460VAC applied to the drive. The specied voltage
range is 414 to 508VAC. If the incoming voltage is in excess of 508VAC, steps should
be taken to reduce the voltage to within the specied limits.
VSD – HIGH INTERNAL
AMBIENT TEMPERATURE
The VSD logic board contains two inputs from two temperature sensors, which monitor
the unit’s internal ambient temperature. This shutdown is generated when the higher of
the two ambient temperatures exceeds a high limit of 158°F (70°C). The unit’s fan(s)
and water pump(s) remain energized until the internal temperature drops below 148°F
(64°C), after which they shall be de-energized and the fault can be cleared. Some
potential causes for this shutdown are internal VSD fan failure, VSD water pump failure,
entering condenser water temperature higher than design, condenser water ow lower
than required, fouled VSD heat exchanger, or restriction of condenser water to the VSD.
TABLE 8 - CYCLING SHUTDOWN MESSAGES (CONT'D)