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PREVENTATIVE MAINTENANCE
It is the responsibility of the owner to provide the nec-
essary daily, monthly and yearly maintenance require-
ments of the system. IMPORTANT – If a system failure
occurs due to improper maintenance during the war-
ranty period; YORK will not be liable for costs incurred
to return the system to satisfactory operation. The fol-
lowing is intended only as a guide and covers only the
chiller unit components. It does not cover other related
system components which may or may not be furnished
by YORK. System components should be maintained
according to the individual manufacturers' recommen-
dations as their operation will affect the operation and
life of the chiller.
DAILY MAINTENANCE
It is recommended that the following items be checked
daily.
1. Oil Level – Correct oil level is when oil appears in
either of the compressor oil sight glasses after the
unit has been in operation for about two hours. If it
necessary to add oil after this operating period, see
item #3 under the ANNUAL MAINTENANCE section.
2. Oil Pressure – Oil pressure should be a minimum of
20 PSI above suction pressure.
3. Compressor Superheat – Correct superheat is
10-15°F measured at the compressor.
4. Operating Pressures and Temperatures – Check to
see that operating pressures and temperatures are
within the LIMITATIONS shown in this book.
WEEKLY MAINTENANCE
It is recommended that the following items be checked
weekly.
1. All items listed under DAILY MAINTENANCE.
2. Color of Compressor Oil – New oil is clear, and if the
system is not contaminated with moisture and/or for-
eign material, should retain its new appearance for a
reasonable length of operating time. Discoloration of
the oil, either turning darker brown or in some cases
lighter, is an indication of contamination, basically due
to moisture. If it is necessary to charge oil refer to
item #3 under the ANNUAL MAINTENANCE section.
3. Check the refrigerant circuit for leaks.
ANNUAL MAINTENANCE
It is recommended that the following items be checked
annually.
1. All items listed under WEEKLY MAINTENANCE.
2. Operating Controls – Check to see if controls are set
and operating within the proper limits. See Operat-
ing Controls in the OPERATION section of this book.
3. Compressor Oil – Drain inspect and refill with new
oil. This requires pumping out the compressor. If
possible, this should be done after the unit has been
in operation for some time, when the oil in the crank-
case will contain the least amount of refrigerant. To
pump out the compressor proceed as follows:
YORK INTERNATIONAL
(YCHA100)
A. Close the suction stop valve.
B. Open the discharge stop valve two turns of the stem.
C. Operate the compressor until 15 to 20 inches vacuum
is obtained. Do this by disconnecting the wiring to
LLSV and repeatedly starting the compressor. Re-
cycle 115VAC power to the Logic Panel to reduce
anti-recycle time to 2 min. if needed. The compres-
sor should in no case be operated under vacuum
conditions for longer than 10 to 15 seconds.
D. Stop the compressor and immediately close the
discharge stop valve. The procedures outlined in
steps (b) and (c) above should be repeated if the
suction pressure rises rapidly to 15 PSIG or more
which would indicate considerable refrigerant re-
maining in the crankcase oil. Do not expect to re-
tain 0 PSIG, since some refrigerant will continu-
ally be released from the oil in the crankcase.
E. After pumping down the compressor, wait until the
pressure builds up to 2 or 3 PSIG before opening
up any part of the hermetic compressor.
F. Open the oil drain valve slowly and drain as much
oil from the compressor as possible.
G. Examine the oil for any metal particles which would
indicate wear on the bearings, crankshaft or
connecting rods. If metal particles are found, the
need for closer examination by factory service per-
sonnel is indicated.
H. If the oil is clean and free of metal particles, refill the
compressor with YORK oil "C". To add oil or to fill the
compressor crankcase, connect the delivery tube of
the YORK Hand Oil Pump, YORK Part No. 470-
10654 or equal to the compressor oil charging and
drain valve. Expel all air from the delivery tube by
pumping it full of oil, allowing a few drops to drip out
before tightening the flare nut to the oil charging valve.
Then open the oil charging valve and pump oil into
the crankcase to the proper level. It is necessary
that the suction end of the hand oil pump be kept
submerged under the oil level in the container at all
times to avoid entrance of air into the compressor.
I. Before opening the suction or discharge stop valves,
connect a vacuum pump to the pump-out port in
the discharge stop valve. (Pumpdown port is port
on valve stem side of valve.) With the vacuum line
shutoff valve open, run the vacuum pump until a
vacuum of at least 1000 microns is reached. Stop
the vacuum pump, close the shut-off valve and open
the discharge valve fully before disconnecting the
line from the vacuum pump. Disconnect the vacuum
pump and replace the plug in the pump-out port.
NOTE: If suction or discharge valves are not properly
seated, a 1000 micron vacuum will not be obtained.
Do not evacuate for extended periods of time.
J. Be sure both discharge and suction stop valves
are open before operating the unit.
4. Suction and Discharge Valves – The condition of the
suction and discharge valves should be checked by
YORK service personnel.
FORM 150.40-NM20
33
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