38
YORK INTERNATIONAL
SINGLE CIRCUIT UNITS
Each YCA (Style “D”) chiller is equipped with a micro-
processor control panel (sometimes referred to as a
“Smart Panel”. The panel not only serves as a means of
accurate, reliable chiller operation; but also as a valu-
able service (or trouble-shooting) aid. To obtain the great-
est benefit from the panel, the operator or service tech-
nician must be familiar with the way it operates. The
following steps are suggested:
1. Study (and re-study) the preceding pages on “Unit
Controls and Operational”.
2. Observe the panel frequently during normal opera-
tion.
3. Keep a daily “log sheet” of normal operating condi-
tions such as pressures, temperatures, motor cur-
rent, etc. See list below.
4. Do not attempt to service or diagnose the unit unless
you have completed the above steps.
This procedure will help you to make a prompt, accu-
rate diagnosis of most operating problems.
The following trouble-shooting chart lists some common
problems, their cause and suggested solution(s). Prob-
lems beyond the scope of this manual should be re-
ferred to the local YORK Service Representative.
GENERAL
Before starting any service, or attempting to correct an
operating problem the operator should “dial up” the Data
Display Codes and complete the following chart (also
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 charg-
ing 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 con-
tainer 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. (Pump-out port is
port on valve stem side of valve.) With the vacuum
line shut-off 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 seated
properly, a 1000 micron vacuum can not be ob-
tained. Do not evacuate for long 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.
TROUBLESHOOTING
refer to page 18).
DO THIS BEFORE CHANGING THE
POSITION OF ANY TOGGLE SWITCHES OR RE-CY-
CLING POWER. CHANGING THE POSITION OF THE
SYSTEM TOGGLE SWITCH OR RE-CYCLING
POWER WILL RESULT IN LOSS OF ALL STORED
DATA AT THE TIME OF FAULT.
0. Return chilled water temperature °F (°C)
1. Leaving chilled water temperature °F (°C)
2. Optional
Not used
3. Optional
4. Low leaving water temperature cutout setting
°F (°C)
5. Chilled water setpoint °F (°C)
6. Outside Air Temperature °F (°C)
7. Low Ambient Temp. Cutout Setting °F (°C)
8. % Full load motor current
9. Suction pressure PSIG (kPaG)
10. Oil pressure PSID (kPaD)
11. Discharge pressure PSIG (kPaG)
12.
13.
14. Not used on YCAQ10, R11
15.
16. Suction pressure cutout setting PSIG (kPaG)
17. Optional – Not used
18. Fault code (if any) see page 40.
Review the recorded data and check any suspicious
values using test equipment that is calibrated accurate-
ly (pressure gauges, temperature probes, digital volt
meters, etc.) to verify the Date Display Code readings in
a no-fault condition. Note any significant difference.
Check that all sensors are properly installed and that
the wiring to the sensors is not cut or shorted. Check
that all manual stop valves on unit are open.
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