YORK INTERNATIONAL
92
Pressing the Operating Data key a SECOND time be-
fore pressing the Enter key causes the following mes-
sage to be displayed:
The Enter key can now be used to scroll through the
operating data starting at the data specific to Systems
1 and 2.
Pressing the Operating Data key a THIRD time before
pressing the Enter key causes the following message
to be displayed:
The Enter key can now be used to scroll through the
operating data starting at the data specific to System 3.
Common Data:
The Common operating data messages and their mean-
ings are as follows:
This message shows the time remaining on the Load
Timer and the Unload Timer. These Timers constantly
recycle and are used in conjunction with rate control
and temperature deviation from setpoint to determine
when loading should occur.
NOTE: These timers may appear not to count accord-
ing to actual time. This is normal as a result of
the micros algorithm compensating for chang-
ing loading requirements.
The upper message gives the difference (error) between
the actual leaving chilled water temperature and the
programmed Target temperature. The lower message
gives the rate of change of the chilled liquid leaving tem-
perature in degrees per minute. The minus sign indi-
cates falling temperature. No sign indicates rising tem-
perature.
This message advises which system is selected as lead,
first lag and second lag. In this case, System 1 is in
lead followed by Systems 2 then 3.
This message indicates the position of the auxiliary con-
tacts (optional) for the evaporator water pump:
ON = contacts closed, OFF = contacts open.
Evaporator Heater control depends on ambient tem-
perature as follows: If measured ambient falls below
40°F, the Evaporator Heater is switched ON. If mea-
sured ambient then rises above 45°F, the heater is
switched OFF. The evaporator heater prevents water
standing in the evaporator from freezing.
System Data:
Pressing Enter again gives the following message:
This advises that the common data has been completed
and that pressing the Enter key will now scroll through
the system data for the master section of the chiller, i.e.
the data for System 1 followed by the data for System
2. Pressing the Operating Data key twice jumps directly
to this point.
The data for each system is provided through the five
displays as described under YCAS 2 System Models
System Data above.
After completing the system data for the master sec-
tion, pressing Enter again gives the following message:
Pressing the Enter key will now scroll through the sys-
tem data for System 3. Pressing the Operating Data
key three times jumps directly to this point.
At the end of this sequence, the displays scroll back to
the beginning of the common data section.
P R E S S
E N T E R
T O
D I S P L A Y
M A S T E R
D A T A
P R E S S
E N T E R
T O
D I S P L A Y
S
U B
D A T A
L O A D
T I M E R
7 0
S E C
U N L O A D
T I M E R
6 0
S E C
T E M P
E R R O R
1 2 . 0
° F
T E M P
R A T E
-
0 . 9
° F / M
L E A D
L A G
S E Q U E N C E
S Y S
1 , 2 , 3
E V A P O R A T O R
W A T E R
P U M P
S T A T U S
O N
E V A P O R A T O R
H E A T E R
S T A T U S
O N
P R E S S
E N T E R
T O
D I S P L A Y
M A S T E R
D A T A
P R E S S
E N T E R
T O
D I S P L A Y
S
U B
D A T A
