52
YORK INTERNATIONAL
The micro will accept a range of programmable values
between 200-399 PSIG for this cut-out. For this cut-out
to be functional, the Discharge Pressure Readout Op-
tion must be installed.
NOTE: It is required to first key in 0 when program-
ming this cut-out (Example: 0270 PSIG).
More details on this safety are outlined in the SYSTEM
SAFETIES section.
OUTSIDE AIR TMP LOW CUT-OUT
The OUTSIDE AIR TMP LOW CUT-OUT does not apply
to indoor chillers, however it must be properly pro-
grammed or it will not allow the chiller to operate. Im-
proper programming will cause the chiller to lock out on
a Low Ambient Fault.
The Low Ambient Cut-out
MUST
be programmed to 00.0
to allow the chiller to operate. A programmed cut-out of
any other value will prevent operation and cause a Low
Ambient Fault.
The micro will accept a range of programmable values
between 00.0° - 50.0°F for this cut-out, if S1 Dip Switch
#2 on the Microprocessor Board is in the CLOSED posi-
tion. As mentioned above, the programmed value MUST
be 00.0. In the OPEN position, a fixed 25°F cut-out is
recognized and will prevent the cut-out from being pro-
grammed properly.
To program the OUTSIDE AIR TMP LOW CUT-OUT, key
in 00.0 and press the ENTER key. The new value will be
entered into memory and the display will advance to the
next user programmable limit.
If for some reason the chiller shows a Fault on low ambi-
ent, reprogram the cut-out for 00.0. After the cutout is
reprogrammed, remove control panel power for about 10
seconds. The fault will clear after power is re-applied.
OUTSIDE AIR TMP HIGH CUT-OUT
The OUTSIDE AIR TMP HIGH CUT-OUT is selectable to
establish the high ambient cut-out point. If the ambient
rises above this point, the chiller will shut down. Restart
can occur when temperature drops below the cut-out.
This only applies to outdoor air-cooled chillers.
This cut-out is normally set at 130.0°F to allow opera-
tion to the absolute maximum temperature capability of
the electro-mechanical components.
To program the OUTSIDE AIR TMP HIGH CUT-OUT, key
in the desired value and press the ENTER key. The new
value will be entered into memory and the display will
advance to the next user programmable limit.
The micro will accept a range of programmable values
between 100.0° - 130.0°F for this cut-out.
NOTE: This cut-out does NOT apply to YCW & YCR
indoor chillers.
DISCHARGE PRESSURE UNLOAD
The DISCHARGE PRESSURE UNLOAD point is a pro-
grammable limit to keep the system from faulting on the
high discharge pressure cut-out should a system prob-
lem or chiller problem occur. A typical problem would be
if the cooling tower would become dirty on a water-cooled
system. Pressure would rise and eventually cause the
chiller to fault causing total loss of cooling. By unloading
the compressors at high discharge pressures, the chiller
is allowed to continue to run automatically at reduced
capacity until the dirty cooling tower can be attended to.
When the unload point is reached, the micro will auto-
matically totally unload the affected compressor. Typi-
cal maximum programmed limits would be 340 PSIG for
YCR chillers with 360 PSIG high pressure cut-outs and
250 PSIG for water-cooled chillers with 270 PSIG cut-
outs.
Reloading will occur when the discharge pressure drops
to 60 PSIG below the programmed unload pressure and
will increment one stage at a time as dictated by the
loading timers.
To program the DISCHARGE PRESSURE UNLOAD, key
in the desired value and press the ENTER key. The new
value will be entered into memory and the display will
advance to the next user programmable limit.
The micro will accept a range of programmable values
between 200-390 PSIG for the unload point. For this fea-
ture to be functional, the Discharge Pressure Readout
Option must be installed.
NOTE: It is required to first key in a 0 when program-
ming this cut-out (Example: 0255 PSIG).
O U T S I D E
A I R
T M P
L O W
C U T O U T
=
2 5 . 0
F
O U T S I D E
A I R
T M P
H I G H
C U T O U T
=
1 3 0 . 0
F
D I S C H A R G E
P R E S S U R E
U N L O A D
=
3 6 0
P S I G
Summary of Contents for YCWJ45EE0
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