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Form 201.23-NM2
Issue date: 12/19/2023
HISTORY
KEY
Figure 137 - 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, etc., shutdowns that
are non-safety related shutdowns. Once the selection
is made, the (ENTER) key must be pressed to enter
the selection.
Johnson Controls
History key
Normal shutdowns history
If the NORMAL SHUTDOWNS History is selected,
the following screen will be displayed:
NORM HIST XX 18-JUN-20004 10:34:58 AM
YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
XX is the normal shutdown number. The display will
provide 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 will typically be displayed on a
normal shutdown due to shutdown on lack of cooling
demand.
NORM HIST XX 18-JUN-20004 10:34:58 AM
SYS X COOLING DEMAND SHUTDOWN
Section 8 - Micropanel
LD10605
8
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