York Millennium YCAS Series, Installation Operation & Maintenance

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YORK INTERNATIONAL
FORM 201.18-NM4
If an error is made while programming or a change is re-
quired, 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 follow-
ing 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 mes-
sage appears on the display the inter-
nal clock, calendar and program set-
tings cannot be relied on for accuracy.
Default values are loaded into the mi-
croprocessor memory and the Manual
Override key can be used to zero out
the daily schedule and allow unlimited
operation regardless of the time on the
internal clock. Reprogramming of the
setpoints and cutout values may also be
necessary. When the MANUAL OVER-
RIDE key is pressed the low battery
message will disappear. If a power fail-
ure should again occur, the above pro-
cess will again need to be repeated to
bring the chiller back on line. See also
Section 2.5.
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