Johnson Controls YORK OPTIVIEW CONTROL CENTER, Operation Manual

Page: 109 / 142

JOHNSON CONTROLS
109
SECTION 3 - OPTIVIEW DISPLAY MESSAGES
FORM 160.10-O1
ISSUE DATE: 4/27/2018
3
a set threshold, the IGBT is gated off and a shutdown
pulse is sent to the VSD logic board shutting down the
entire VSD system. A gate driver fault can be initiated
when the VSD is not running.
VSD Initialization Failed
Upon application of power, all VSD boards go through
the INITIALIZATION PROCESS. During this pro-
cess, memory locations are cleared, program jumper
positions are checked and serial communication links
are established. There are several causes for unsuccess-
ful initialization as follows:
• The OptiView Control Center and the VSD must
be energized at the same time. Pulling the fuse in
the OptiView Control Center to remove power
from the OptiView will create this fault. Power-up
must be accomplished by closing the main discon-
nect on the VSD cabinet with all fuses in place. A
power interruption to the VSD Logic board will
also generate this message.
• The Eproms must be of the correct version for
each VSD board and they must be installed cor-
rectly. The eproms are created as a set, and can-
not be interchanged between earlier and later ver-
sions.
• Serial data communication must be established.
Refer to VSD – SERIAL COMMUNICATIONS
fault. If communication between the VSD logic
board, harmonic filter logic board, ACC board and
OptiView Control Center microboard does not
take place during initialization, this message will
be generated. Proper serial communications can
be verified by selecting the VSD DETAILS screen
from the MOTOR screen and observing the FLA
value. A zero displayed for this and other VSD pa-
rameters, indicates a serial communications link
problem.
• If the harmonic filter option is included, make
sure the filter logic board is not in continuous re -
set. This condition is evidenced by the filter logic
board’s LED’s alternately blinking. The filter can
be eliminated as a cause of initialization failure by
disconnecting the filter. Place switch SW1 on the
filter logic board in the OFF position and remov -
ing the ribbon cable between the filter logic board
and the VSD logic boards to check.
• VSD and harmonic filter horsepower ratings do
not agree.
VSD – Low DC Bus Voltage
If the DC link drops below 500 VDC (or 414 VDC
for 50 Hz applications), the VSD will initiate a system
shutdown. A common cause for this shutdown is a se-
vere sag in the incoming power to the drive. Monitor
the incoming three-phase AC line and DC link for se-
vere sags with a voltmeter.
VSD – High DC Bus Voltage
The VSD’s DC link voltage is continuously monitored
and if the level exceeds 745 VDC, a bus over-voltage
shutdown is initiated. If this shutdown occurs, the level
of the 460 VAC applied to the drive must be checked.
The specified voltage range is 414 to 508 VAC. If the
incoming voltage is in excess of 508 VAC, steps should
be taken to reduce the voltage to within the specified
limits.
VSD – High Phase (X) Instantaneous Current
This shutdown is generated by the VSD if the motor
current in phase A, B, or C (denoted as X above) ex-
ceeds a given limit. The motor current is sensed by the
current transformers on the VSD output pole assem-
blies and the signals are sent to the VSD logic board
for processing. Maximum instantaneous permissible
currents are:
• 351/292 HP: 771 Amps
• 503/419 HP: 1200 Amps
• 790/658 HP: 1890 Amps
If an overcurrent trip occurs, but the chiller restarts and
runs without a problem, the cause may be attributed
to a voltage sag on the utility power feeding the VSD
that is in excess of the specified voltage range. This is
especially true if the chiller was running at or near full
load. If there is a sudden dip in line voltage, the cur-
rent to the motor will increase, since the motor wants
to draw constant horsepower. The chiller pre-rotation
vanes cannot close quickly enough to correct for this
sudden increase in current, and the chiller will trip on
an overcurrent fault.
If the chiller will not restart, but keeps tripping on this
same fault, an output pole problem is the most likely
cause and the VSD would require service.