York YCAL Series, Installation Operation & Maintenance

Page: 112 / 174

JOHNSON CONTROLS
112
FORM 150.66-NM3
ISSUE DATE: 09/25/2020
SECTION 7 - UNIT CONTROLS
History Displays
The HISTORY key gives the user access to many unit
and system operating parameters at the time of a unit
or system safety shutdown. When the HISTORY key is
pressed the following message is displayed.
D I S P L A Y S A F E T Y S H U T-
D O W N N O . 1 ( 1 T O 6 )
While this message is displayed, the ↑ (UP) arrow key
can be used to select any of the six history buffers. Buf -
fer number 1 is the most recent, and buffer number 6 is
the oldest safety shutdown that was saved.
After selecting the shutdown number, pressing the EN-
TER key displays the following message which shows
when the shutdown occurred.
S H U T D O W N O C C U R R E D
0 3 : 5 6 P M 2 9 J A N 0 2
Pressing the ↓ (DOWN) arrow key repeatedly from the
DISPLAY SAFETY SHUTDOWN NO. X displays the
software version.
S O F T W A R E V E R S I O N
C . M M C . 0 4 . 0 1
The ↑ (UP) and ↓ (DOWN) arrow keys are used to
scroll forward and backward through the history buffer
to display the shutdown conditions stored at the instant
the fault occurred. The ↓ (DOWN) arrow key scrolls
through the displays in the order they appear below:
U N I T F A U L T :
L O W L I Q U I D T E M P
Displays the type of fault that occurred.
U N I T T Y P E
L I Q U I D C H I L L E R
Displays the type of chiller; Liquid, Condensing Unit
or Heat Pump.
C H I L L E D L I Q U I D
X X X X X
Displays the chilled liquid type; Water or Glycol.
History Printout
Pressing the PRINT key and then the HISTORY key
allows the operator to obtain a printout of information
relating to the last 6 Safety Shutdowns which occurred.
The information is stored at the instant of the fault, re-
gardless of whether the fault caused a lockout to occur.
The information is also not affected by power failures
(long-term internal memory battery backup is built into
the circuit board) or manual resetting of a fault lock-
out.
When the HISTORY key is pressed, a printout is trans-
mitted of all system operating conditions which were
stored at the “instant the fault occurred” for each of the
6 Safety Shutdowns buffers. The printout will begin
with the most recent fault which occurred. The most
recent fault will always be stored as Safety Shutdown
No. 1. identically formatted fault information will then
be printed for the remaining safety shutdowns.
Information contained in the Safety Shutdown buffers
is very important when attempting to troubleshoot a
system problem. This data reflects the system condi -
tions at the instant the fault occurred and often reveals
other system conditions which actually caused the
safety threshold to be exceeded.
The history printout is similar to the operational data
printout shown in the previous section. The differences
are in the header and the schedule information. The
daily schedule is not printed in a history print.
One example history buffer printout is shown follow -
ing. The data part of the printout will be exactly the
same as the operational data print so it is not repeated
here. The difference is that the Daily Schedule is not
printed in the history print and the header will be as
follows.
YORK INTERNATIONAL CORPORATION
MILLENNIUM LIQUID CHILLER
SAFETY SHUTDOWN NUMBER 1
SHUTDOWN @ 3:56PM 29 JAN 08
SYS 1 HIGH DSCH PRESS SHUTDOWN
SYS 2 NO FAULTS