York YCAS 0138EB, Installation Operation & Maintenance

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JOHNSON CONTROLS
FORM 201.18-NM7
If an error is made while programming or a change is
required, press Cancel. This will clear the programmed
(*) “Holiday” days (the “0” key will not cancel out a
“ * ” and cannot be used for correcting a programming
error).
7.4 MANUAL OVERRIDE KEY
When the Manual Override key is pressed, the Daily
Schedule programmed into the chiller is ignored and
the chiller will start up when water temperature is above
the high limit of the Control Range, the Chiller ON/OFF
switch is ON, remote cycling devices are CLOSED, and
system switches permit.
Normally this key is only used for servicing when the
chiller is required to run but the Daily Schedule is in
an OFF period. This key avoids the need to reprogram
the Daily Schedule. Once activated, Manual Override is
only active for a period of 30 minutes and the following
status message will be observed:
M A N U A L
O V E R R I D E
If a Warning – Low Battery fault
message appears on the display the
internal clock, calendar and program
settings cannot be relied on for accu‑
racy. Default values are loaded into the
microprocessor memory and the Man‑
ual Override key can be used to zero
out the daily schedule and allow un‑
limited operation regardless of the time
on the internal clock. Reprogramming
of the setpoints and cutout values may
also be necessary. When the MANUAL
OVERRIDE key is pressed the low bat‑
tery message will disappear. If a power
failure should again occur, the above
process will again need to be repeated
to bring the chiller back on line. See
also Section 2.5.
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