YCWL/YCRL units), is open and the unit will not run or if
running, pumpdown and stop. A pumpdown and stop
due to the flow switch opening is recorded in history as a
UNIT FAULT: FLOW SWITCH OPEN, but no remote
alarm is given.
The system switch under 'OPTIONS' is turned off. The
system will not be allowed to run until the switch is
turned back on.
The chilled liquid temperature is below the point
(determined by the ‘SETPOINT’ and 'RANGE') that the
microprocessor will bring on a system or that the
microprocessor has not loaded the lead system far
enough into the loading sequence to be ready to bring
the lag system on. The lag system will display this
message until the loading sequence is ready for the lag
system to start.
Indicates that the respective system is running due to
demand. The 'X' will be replaced with the number of
compressors in that system that are running.
Shows the amount of time left on the respective systems
anti-recycle timer. This message is displayed when the
system is unable to start due the anti-recycle timer being
active.
The anti-coincident timer is a software feature that
guards against 2 systems starting simultaneously. This
assures instantaneous starting current does not
become excessively high due to simultaneous starts.
T h e m i c r o p r o c e s s o r l i m i t s th e t i m e b e t w e e n
compressor starts to 1 minute regardless of demand or
the anti-recycle timer being timed out.
Discharge pressure limiting is in effect. The limiting
pressure is a factory set limit to keep the system from
faulting on the high discharge pressure cutout due to
high load or pull down conditions. When the unload point
is reached, the microprocessor will automatically unload
the affected system by de-energising one compressor.
The discharge pressure unload will occur when the
discharge pressure gets within 0.7 barg of the
programmed discharge pressure cutout. This will only
happen if the system is fully loaded and will shut only
one compressor off. Discharge limiting will prevent the
last compressor in a system from starting if the
discharge pressure is above 85% of the programmed
discharge pressure cutout. Reloading the affected
system will occur when the discharge pressure drops to
85% of the unload pressure and 10 minutes have
elapsed.
Suction pressure limiting is in effect. The suction
pressure limit is a control point that limits the loading of a
system when the suction pressure drops to within 15%
above the suction pressure cutout. On a standard
system programmed for 6.0 bar suction pressure cutout,
the microprocessor would inhibit loading of the affected
system with the suction pressure less than or equal to
1.15 * 6.0 bar = 6.9 bar. The system will be allowed to
load after 60 seconds and after the suction pressure
rises above the suction pressure limit point.
Suction pressure limiting will not unload a
system. Suction pressure limiting only
prevents further loading.
Load limiting is in effect at the percentage shown. This
limiting could be due to a load limit/PWM input (-ARB
circuit board on YLAA and YLAE units or -XTBC1 on
YCWL/YCRL units) or an ISN, Bacnet or Modbus load
limit command.
'MANUAL OVERRIDE' mode is selected under the
'OPTIONS' key. In this mode the 'Daily Schedule' is
ignored and the chiller will start-up when chilled liquid
temperature allows and the flow switch/remote
contacts, unit switch and system switches permit. This is
a priority message and cannot be overridden by other
'STATUS' messages.
1
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16
Form 201.26.OI1(11/09)
S Y S
1
S Y S
S W I
T C H
O F F
S Y S
2
S Y S
S W I
T C H
O F F
S Y S
1
N O
C O O L
L O A D
S Y S
2
N O
C O O L
L O A D
S Y S
1
C O M P S
R U N
X
S Y S
2
C O M P S
R U N
X
S Y S
1
A R
T I
M E R
X X
S
S Y S
2
A R
T I
M E R
X X
S
S Y S
1
A C
T I
M E R
X X
S
S Y S
2
A C
T I
M E R
X X
S
S Y S
1
D S C H
L I
M I
T I
N G
S Y S
2
D S C H
L I
M I
T I
N G
S Y S
1
S U C T
L I
M I
T I
N G
S Y S
2
S U C T
L I
M I
T I
N G
S Y S
1
L O A D
L I M I T
X X %
S Y S
2
L O A D
L I M I T
X X %
M A N U A L
O V E R R I
D E
