York MILLENNIUM YCAS, Installation Operation & Maintenance

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YORK INTERNATIONAL
FORM 201.18-NM2
System Data:
The following sequence of three displays are provided
first for System 1, then for System 2, and then for Sys-
tems 3 and 4 as applicable.
This message displays the accumulated Run Time since
the last start in Days (D), Hours (H), Minutes (M), and
Seconds (S).
This message indicates the Liquid Line Solenoid Valve
and the economizer TXV solenoid valve position: ON =
Energized/Open, OFF = De-energized/Closed.
This message advises the stage of condenser fan op-
eration on this system and the status of the compressor
heater. See Section 8.4 for details of fan staging.
Once the System Data sequence has been repeated for
the second system, pressing the
á á
á á á
or
â â
â â â
key again will
loop back to the beginning to the Load/Unload Timer
display. To leave the sequence at any point press a key
from another section of the keypad.
Pressing the “ * ” at any time while in
the OPER DATA mode displays the
EPROM software version being used,
as shown below:
YCAS 3-System Models
YCAS 3-System Models are constructed in two sec-
tions. One section contains number 1 and 2 refrigerant
systems plus the common three circuit evaporator. The
second section contains the number 3 refrigerant sys-
tem. Both systems have their own control panel, but
only the System 1 and 2 panel is fitted with a keypad
and display.
The upper message gives the difference (error) between
actual leaving chilled liquid temperature and the pro-
grammed Target temperature. The lower message gives
the rate of change of the chilled liquid leaving tempera-
ture in degrees per minute. A minus sign (-) indicates
falling temperature. No sign indicates rising temperature.
This message advises which system is programmed as
the lead.
This message indicates the position of the optional aux-
iliary contacts for the evaporator water pump and the
status of the evaporator heater.
For the evaporator pump contacts, ON = contacts closed,
OFF = contacts open.
The Evaporator Heater status is controlled on ambient
temperature as follows : If measured ambient falls be-
low 4°C (40ºF) the Evaporator Heater is switched ON.
If measured ambient then rises above 7°C (45ºF) the
heater is switched OFF. The evaporator heater prevents
water standing in the evaporator from freezing.
This message indicates that a remote device such as a
Remote Control Center, an ISN controller, or another
device sending a PWM signal for temperature or cur-
rent reset is overriding control points programmed
through the keypad or default microprocessor setpoints.
The following displays may be encountered:
NONE – No remote control active. Remote moni-
toring may be active.
ISN – YorkTalk via ISN or Remote Control
Center (remote mode).
PWM CURR – EMS PWM Current Limiting Enabled
PWM TEMP – EMS PWM Temp. Reset Enabled
CUR/TEMP – EMS PWM Current Limiting &
Temperature Reset Enabled
T E M P E R R O R 0 0 . 5 ° F
T E M P R A T E - 0 . 9 ° F / M
L E A D S Y S T E M I S
S Y S T E M N U M B E R #
E V A P P U M P I S O F F
E V A P H E A T E R I S O N
A C T I V E R E M O T E C T R L
N O N E
S Y S # F A N S T A G E 3
C O M P H E A T E R I S O N
S O F T W A R E V E R S I O N
ooooo
C . A 1 4 . 1 0 . 0 1
S Y S # R U N T I M E
1 - 3 - 4 8 - 1 7 D - H - M - S
S Y S # L L S V I S O N
E C O N T X V S O L I S O N
9