York YCAJ44HE8, Инструкция по установке, эксплуатации и обслуживанию, Страница: 15 / 92

FORM 150.60-NM3
15
YORK INTERNATIONAL
Since elbows, tees and valves decrease pump capacity,
all piping should be kept as straight and as simple as
possible.
Hand stop valve should be installed in all lines to facilitate
servicing.
Piping to the inlet and outlet connections of the chiller
should include high-pressure rubber hose or piping loops
to insure against transmission of water pump vibration.
This is optional and the necessary components must be
obtained in the field.
Drain connections should be provided at all low points to
permit complete drainage of liquid cooler and piping sys-
tem.
A small valve or valves should be installed at the highest
point or points in the chilled liquid piping to allow any trapped
air to be purged. Vent and drain connections should be
extended beyond the insulation to make them accessible.
The piping to and from the cooler MUST be designed to
suit the individual installation. It is important that the fol-
lowing considerations be observed:
1. The chilled liquid piping system should be laid out so
that the circulating pump discharges directly into the
cooler. The suction for this pump should be taken from
the piping system return line and not the cooler.
2. The inlet and outlet cooler liquid connection sizes are
given on page 8.
3. A strainer, preferably 40 mesh, MUST be installed in
the cooler inlet line just ahead of the cooler.
4. All chilled liquid piping should be thoroughly flushed to
free it from foreign material before the system is placed
into operation. Use care not to flush any foreign mate-
rial into or through the cooler.
5. As an aid to servicing, thermometers and pressure
gauges should be installed in the inlet and outlet water
lines. One connection point (plugged) is provided in
each cooler nozzle. Thermometers and gauges are not
furnished with the unit and are to be furnished by other
suppliers.
6. The chilled liquid lines that are exposed to outdoor
ambients should be wrapped with a supplemental heater
cable and insulated to protect against freezeup during
low ambient periods, and to prevent formation of con-
densation on lines in warm humid climates.
7. A chilled water flow switch, (either by YORK or others)
MUST be installed in the leaving water piping of the
cooler. There should be a straight horizontal run of at
least 5 diameters on each side of the switch. Adjust
the flow switch paddle to the size of pipe in which it is
to be installed. (See manufacturer’s instructions fur-
nished with switch). The switch is to be wired to termi-
nals in the control panel as shown in the WIRING DIA-
GRAM.
WARNING: Flow switch must not be used to stop and
start chiller. It is intended only as a safety
switch.
COMPRESSOR INSULATION
In high humidity environments, compressor sweating may
be noted. In most applications, this is of no concern. How-
ever, if it is undesirable, it is the responsibility of the in-
staller to make provisions to field insulate the compressor
or install a factory insulation kit when they become avail-
able. Contact YORK Factory Marketing for availability.
ELECTRICAL WIRING
Liquid Chillers are shipped with all factory mounted con-
trols wired for operation.
Field Wiring – Power wiring must be provided through a
fused disconnect switch to the unit terminals (or optional
molded case disconnect switch) in accordance with N.E.C.
or local code requirements. Minimum circuit ampacity and
maximum dual element fuse size are given on pages 10
and 11. A 115-1-60/50, 20 amp source must be supplied
for the control panel through a fused disconnect when a
control panel transformer (optional) is not provided. Refer
to Wiring Diagram, Form 150.60-W2.
Affiliated apparatus, such as a chilled water flow switch,
auxiliary contacts from the chilled water pump starter,
alarms, etc., should be interlocked into the control panel
circuit. These field modifications may be made as shown
on the WIRING DIAGRAM.
MULTIPLE UNITS
For increased compressor protection and to reduce power
inrush at start-up on multiple chiller installations, provi-
sions must be made to prevent simultaneous startup of
two or more units. Also, some method must be employed
to automatically cycle one or more of the units on or off to
permit more efficient operation at part load conditions. A
sequencing kit may be acquired through your local YORK
representative.