Table of Contents
Advertisement
DISPLAY
The 40 Character Display (2 lines of 20 characters) is a
liquid crystal display used for displaying system param-
eters and operator messages.
The display, in conjunction with the keypad, allows the
operator to display system operating parameters as well
as to access programmed information already in memory.
The display has a lighted background for night viewing
and for viewing in direct sunlight.
When a key is pressed, such as the OPER DATA key,
system parameters will be displayed and will remain on
the display until another key is pressed. The system
parameters can be scrolled with the use of the up and
down arrow keys. The display will update all information
at a rate of about 2 seconds.
Display Messages may show characters indicating
"greater than" (>) or "less than" (<). These characters
indicate the actual values are greater than or less than
the limit values which are being displayed.
KEYPAD
The 12 button non-tactile keypad allows the user to re-
trieve vital system parameters such as system pressures,
temperatures, compressor running times and starts,
option information on the unit, and system setpoints.
YORK INTERNATIONAL
This data is useful for monitoring unit operation, diag-
nosing potential problems, troubleshooting, and commis-
sioning the unit.
It is essential the user become familiar with the use of
the keypad and display. This will allow the user to make
full use of the capabilities and diagnostic features avail-
able.
BATTERY BACK-UP
The Microprocessor Board contains a Real Time Clock
integrated circuit chip with an internal battery back-up.
The purpose of this battery back-up is to assure any
programmed values (setpoints, clock, cutouts, etc.) are
not lost during a power failure regardless of the time in-
volved in a power cut or shutdown period.
UNIT STATUS
Pressing the STATUS key will enable the operator to
determine current chiller operating status. The messages
displayed will include running status, cooling demand,
fault status, external cycling device status, load limiting
and anti-recycle/coincident timer status. The display will
be a single message relating to the highest priority mes-
sage as determined by the micro. Status messages fall
into the categories of General Status and Fault Status.
FORM 150.63-NM2
3
97
Advertisement
Table of Contents
