York YK-EP Operation And Maintenance Manual page 202

LCSSS – Logic Board Power Supply
Following application of power, this message is displayed and a snapshot of the LCSSS parameters
and time of power failure are sent to the Control Center.
LCSSS – Phase Rotation/Loss
The Liquid Cooled Solid Starter Logic/Trigger Board has detected the three-phase compressor
motor power line voltage phase rotation is not correct or the line-to-line voltage in any phase has
decreased to less than 30% of nominal. The chiller will automatically restart when the power line
conditions are acceptable.
LCSSS – Phase Loss
The Liquid Cooled Solid State Starter Logic/Trigger Board has detected the line-to-line RMS voltage
in any phase has decreased to less than or equal to 30% of the lowest value of the programed
voltage range. If the programmed voltage range is Disabled, a value of 60VAC is used as the
threshold. The chiller will automatically restart when the line voltage is greater than the shutdown
threshold. The voltage range is programmed by a Service Technician following instructions in
OptiView Control Center – Service Instructions (Form 160.54-M1).
Compressor motor variable speed drive: Cycling shutdown
messages
The following cycling shutdown messages are displayed on Compressor Motor Variable Speed
Drive (VSD) applications only. These messages are generated by events that occur within the VSD.
The chiller will automatically restart when the cycling condition clears. Service and troubleshooting
information is contained in Variable Speed Drive – Service Instructions (Form 160.00-M1).
VSD Shutdown – Requesting Fault Data
The VSD has shutdown the chiller and the Control Center has not yet received the cause of the fault
from the VSD, via the serial communications link. The VSD shuts down the chiller by opening the
Motor Controller VSD STOP CONTACTS (located on the VSD Logic Board and connected between
TB6-16 and TB6-53 in the Control Center). The Microboard in the Control Center then sends a
request for the cause of the fault to the VSD Logic Board via the Adaptive Capacity 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 below listed fault messages.
VSD – Stop Contacts Open
Refer to VSD Shutdown – Requesting Fault Data. If the Control Center's Microboard does not receive
the cause of the fault over the Serial Link within 20 seconds, it is assumed it is not forthcoming and
that message is replaced with VSD – STOP CONTACTS OPEN message.
VSD Initialization Failed
Upon application of power, all boards go through the initialization process. At this time, memory
locations are cleared, program jumper positions are checked and serial communications links are
established. There are several causes for an unsuccessful initialization as follows:
• The Control Center and the VSD must be energized at the same time. The practice of
pulling the fuse in the Control Center to remove power from the Control Center will create a
problem. Power-up must be accomplished by closing the main disconnect 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
correctly. The EPROMs are created as a set, and cannot be interchanged between earlier and
later versions.
202 YK-EP Style B Centrifugal Chiller