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FORM 195.26-NM3

YORK INTERNATIONAL

FIELD INSTALLATION

If it becomes necessary to field install the Hot Gas
(Loadminder) Option, two kits are required. The part
numbers of the kits are 471-01232-101 Relay Output
Board Kit and either 375-07021-001 (YCUZ33, 44 and
74) or 375-07021-002 (YCUZ77 and 88) Hot Gas By-
pass Kit. The 475-01232-101 Hot Gas kit consists of a
second Relay Output Board. It is not required if two
Relay Boards are already installed in the control panel.
If the 375-07021-001/002 Hot Gas kit is not available,
the following parts should be ordered separately for
the kit required.

DISCHARGE PRESSURE READOUT OPTION

The Discharge Pressure Read-out Option P/N 471-
01262-111 allows the user to obtain control panel dis-
plays of discharge pressure. Additionally, other displays
such as fault information will then hold relevant dis-
charge pressure information useful in diagnosing prob-
lems.

The discharge pressure unloading feature also becomes
usable when this option is installed (Page 37) as well
as fan cycling by discharge pressure.

Fan cycling by discharge pressure sometimes becomes
necessary, if ambient temperature cycling of fans
causes low suction pressure faults due to unusual op-
erating conditions or chiller location problems. Fan cy-
cling by discharge pressure only, allows higher dis-
charge pressures which in turn raises pressure by per-
mitting better operation of the thermal expansion valve.
To convert to discharge pressure cycling, the micro
panel must be programmed for DISCHARGE PRES-
SURE FAN CONTROL (See page 31). Fan cycling will
operate as indicated in Table 5.

The kit consists of discharge pressure transducers for
each system, wire harnesses, and associated mount-
ing hardware.

HIGH AMBIENT OPTION

The High Ambient Option consists of two kits, P/N’s
471-01262-111 (Discharge Pressure Readout Kit) and
475-05838-000 (Sunshield Kit). The option allows op-
eration of the chiller in ambients up to 115°F. Typically,
standard operation is limited to 105°F. High ambient
operation is accomplished by discharge pressure un-
loading to assure that the chiller does not fault due to
the high pressure cut-out opening during high tem-
peratue operation. A sun shield is also installed on the
control panel to prevent direct sunlight from overheat-
ing the control panel causing subsequent malfunction
of the electro-mechanical and electronic components
in the control panel. Additionally, actual discharge pres-
sure read-outs can now be obtained from the micro
panel.

Discharge Pressure unloading allows the microproces-
sor to unload a compressor when the discharge pres-
sure approaches a point nearing the discharge pres-
sure cut-out. This assures that the system does not
shut down completely if the cut-out were to open. See
Page 36 for programming the unloading pressure.

Fan cycling by discharge pressure is also available
when this option is installed (see DISCHARGE PRES-
SURE READ-OUT OPTION, page 71; however, it is of
little use in areas where ambients are generally high
and standard temperature control of the fans provides
good control and maximum efficiency.

LOCAL PRINTER OPTION

The Micro Panel is capable of supplying a print-out of
chiller conditions or fault shutdown information at any
given time. This allows operator and service personnel
to obtain data and system status with the touch of the
keypad. In addition to manual print selection, the micro
panel will provide an automatic print-out whenever a

PARTS LIST (HOT GAS)

ITEM QTY DESCRIPTION

375-07021-001

375-07021-002

PART NO.

0001

Solenoid Valve

375-00223-014

0002

Bracket

066-94986-000

0003