Unit Warnings - York YCAV0267E Installation Operation & Maintenance

MICRO PANEL
Unit Warning Operation
Unit warnings are caused when a condition is pres-
ent requiring operator intervention to restart the unit.
All setpoints, program values, and options should be
checked before operating the unit. Warnings are not
logged to the history buffer. If a unit warning is in ef-
fect, the message will be displayed to the operator when
the Status key is pressed.
STATUS
KEY
Low Battery Warning
The LOW BATTERY WARNING can only occur at
unit power-up. On micropanel power-up, the RTC bat-
tery is checked to see if it is still operational. If it is,
normal unit operation is allowed. If the battery voltage
is determined to be low, the following warning message
is displayed indefinitely.
UNIT WARNING: !! LOW BATTERY !!
CHECK SETPOINTS/PROGRAM/OPTIONS/TIME
If a low battery condition exists, all programmed
setpoints, program values, time, schedule, and history
buffers will have been lost. These values will all be reset
to their default values, which may not be the desired
operating values. Once a bad battery is detected, the
unit will be prevented from running until the MANUAL
OVERRIDE key is pressed. Once the MANUAL
OVERRIDE key is pressed, the anti recycle timers will
be set to the programmed default anti recycle time to
allow the operator sufficient time to check setpoints,
program values, etc.
248

UNIT WARNINGS

If a low battery is detected, it should be replaced as
soon as possible. The programmed values will all be
lost and the unit will be prevented from running on the
next power interruption. The RTC/Battery is located on
the Chiller Logic Board shown below:
MICROBOARD (331-03478-XXX)
The 331-03478-xxx microboard was developed as a direct
replacement for the 031-02478-xxx line of microboards.
No adapter harness is required when replacing a 02478
with the new 03478. The 03478 uses the IPUII processor
card and provides some new features for the chillers that
the 02478 did not have. The 03478 program resides in
flash memory instead of EPROM. Program updates are
accomplished by loading the new program from an SD
card inserted into the SD card reader/writer. This same
SD card reader/writer also allows the user to datalog the
operating parameters to an SD card every 5 seconds. This
information is invaluable when troubleshooting unit and
system problems since it allows the service technician to
view operating parameters prior to a unit fault. Details
on the new datalogging capability are explained in the
OPTIONS Key area of this manual. A Real Time Clock/
BRAM keeps time and setpoints during power outtages.
POWER SUPPLIES AND LEDS
The 03478 has LEDs to indicate various states of opera-
LD10605
tion of the microboard.
STATUS – Flashes every ½ second to indicate that the
base board processor is running its program.
POWER – On solid indicates that the base board +12V
and +5V power supplies are operational.
TX1 – Red LED flashes when transmitting data out
Port 1 TB3 (Future native communications BAS port)
RX1 – Green LED flashes when receiving data in Port 1
TB3 (Future native communications BAS port)
TX2 – Red LED that flashes when transmitting data
out Port 2 (E-Link TB2 or printer TB1)
RX2 – Green LED that flashes when receiving data in
Port 2 (E-Link TB2 or printer TB1)
VSD_TX – Red LED that flashes when transmitting
data out Port 3 to the VSD Logic board
VSD_RX – Green LED that flashes when receiving
data in Port 3 from the VSD Logic board
24VAC power is applied to the 331-03478-xxx mi-
croboard connector J12 and is then used to create the
various DC power sources required by the microboard
circuitry.
FORM 201.21-NM3 (616)
JOHNSON CONTROLS