
YORK INTERNATIONAL
88
shuts down due to a lockout, is awaiting restart after a
fault, has its system switch(es) on the Micro Board in
the OFF position, or if a run permissive is keeping the
lead system off. This is done to maintain chilled liquid
temperature as close to setpoint as possible. See Sec-
tions 1.12 and 8.2 for additional details & programming.
Closed:
In the Automatic Lead / Lag Mode, lead / lag selection
between compressors and compressor groups is auto-
matic. In this mode the micro attempts to balance run
time between the compressors / groups. The param-
eters for the automatic lead / lag selection are as fol-
lows:
1. If both compressors in a group are ready to start and
the anti-recycle timers are timed out, the compres-
sor with the lowest run hours will start first. If run
hours are equal, the system with the least run hours
will start first.
2. If both compressors in a group are waiting to start
but the anti-recycle timers are not yet timed out, lead
will be assigned to the compressor with the shortest
anti-recycle time in an effort to provide cooling quickly.
3. If the lead compressor / group is locked out, faulted
and waiting to restart, has its system switch on the
micro board in the OFF position, or a run permissive
is keeping an individual system from running, the lag
compressor is swapped to the lead. This occurs
whether the lag compressor / group is on or off. See
Section 1.12 and 8.2 for additional details and
programming.
SWITCH 8: Refrigerant
Open:
The R134a mode MUST be selected for models using
refrigerant R134a. Incorrect selection of this switch may
cause serious damage to the chiller.
Closed:
The R22 mode MUST be selected for models using re-
frigerant type R22. Incorrect selection of this switch may
cause serious damage to the chiller.
Summary of Settings
The following table gives a summary of Modes (displayed
messages) which can be selected using the Open and
Closed positions for each of the eight SW1 Dip Switches:
A U T O M A T I C
L E A D
/
L A G
R E F R I G E R A N T
T Y P E
R 1 3 4 A
R E F R I G E R A N T
T Y P E
R 2 2
SWITCH
SWITCH OPEN
SWITCH CLOSED
SETTING
SETTING
1
Water Cooling
Brine Cooling
2
Standard
Low Ambient
Ambient Control
Control
3
Local Control
Remote Control
Mode
Mode
4
Thermal Expansion
Thermal Expansion
Valves
Valves
5
English Units
SI Units
Readouts
Readouts
6
Across-the-Line
Wye-Delta
Starting
Starting
7
Manual
Automatic
Lead / Lag
Lead / Lag
8
Refrigerant
Refrigerant
R134a
R22
Содержание Millennium YDAS 410
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