History Key - York YVAA Style A Installation Operation & Maintenance

Air-cooled screw liquid chiller
Table of Contents

Advertisement

SECTION 8 - MICROPANEL

History key

History key operation
The HISTORY key provides the user access to many
unit and system operating parameters captured at the
instant a unit or system safety (fault) shutdown occurs.
The history buffer will also capture system data at the
time of normal shutdowns such as cycling shutdowns.
When the HISTORY key is pressed the following
screen is displayed:
HISTORY
CHOOSE HISTORY TYPE
◄ ►
XXXXXXXXXXXXXXXXXXXXXXXXXXXX
The ◄ and ► (ARROW) keys allow choosing be-
tween NORMAL SHUTDOWNS and FAULT SHUT-
DOWNS. Fault shutdowns provide information on
safety shutdowns, while "Normal" shutdowns provide
chiller cycling information on temperature (demand),
cycling, remote, system switch, and so on, shutdowns
that are non-safety related shutdowns. Once the selec-
tion is made, the  (ENTER) key must be pressed to
enter the selection.
Normal shutdowns history
If the NORMAL SHUTDOWNS history is selected,
the following screen will be displayed:
NORM HIST XX 18-JUN-2004 10:34:58 AM
YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
142
History key
XX is the normal shutdown number. The display pro-
vides date and time of the shutdown and the reason for
the cycling shutdown (YYY....).
The operator can view any of the stored 20 single dis-
play normal shutdown history buffers. History buffer
number 1 provides the most recent shutdown informa-
tion and buffer number 20 is the oldest safety shutdown
information saved. The ◄ and ► (ARROW) keys allow
scrolling between each of the history buffers. The ►
(ARROW) key scrolls to the next normal history shut-
down and the ◄ (ARROW) key scrolls to the previous
normal history shutdown.
The following display is displayed on a normal shut-
down due to shutdown on lack of cooling demand.
NORM HIST XX 18-JUN-2004 10:34:58 AM
SYS X COOLING DEMAND SHUTDOWN
Fault shutdowns history
If the FAULT SHUTDOWNS history is selected, the
following screen will be displayed:
FAULT HIST XX 18-JUN-2004 10:34:58 AM
YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
Form 201.28-NM1.1
Issue date: 08/06/2021
LD10605
JOHNSON CONTROLS

Advertisement

Table of Contents
loading

Table of Contents