YORK INTERNATIONAL
34
Each YCHA (Style C) 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 valuable service (or trouble-shooting) aid. To ob-
tain the greatest benefit from the panel, the operator or
service technician must be familiar with the way it oper-
ates. The following steps are suggested:
1. Study (and re-study) the preceding pages on “Unit
Controls and Operation”.
2. Observe the panel frequently during normal operation.
3. Keep a daily “log sheet” of normal operating condi-
tions such as pressures, temperatures, motor cur-
rent, etc. See list at right.
4. Do not attempt to service or diagnose the unit un-
less 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 com-
mon problems, their cause and suggested solution(s).
Problems beyond the scope of this manual should be
referred 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
refer to page 14).
DO THIS BEFORE CHANGING THE
POSITION OF ANY TOGGLE SWITCHES. CHANGING
THE POSITION OF THE SYSTEM TOGGLE SWITCH
WILL RESULT IN LOSS OF ALL STORED DATA.
0. Return chilled water temperature ________°F
1. Leaving chilled water temperature________°F
2. Optional
3. Optional
Not used on YCHA 100
4. Low leaving water temp. cutout setting ____°F
5. Chilled water setpoint _________________°F
6. Outside Air Temperature _______________°F
7. Low Ambient Temp. Cutout Setting _______°F
8. % Full load motor current
9. Suction pressure __________________ PSIG
10.Oil pressure ______________________ PSID
11. Discharge pressure ________________ PSIG
12.Spare
13.Spare
Not used on YCHA 100
14.Spare
15.Spare
16.Suction pressure cutout setting _______ PSIG
17.Optional – Not used on YCHA 100
18.Fault code (if any) see page 14
Using test equipment that is calibrated accurately (pres-
sure gauges, temperature probes, digital volt meters,
etc.) verify the Data Display Code readings logged
above. 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.
TROUBLE-SHOOTING THE YCHA 100 (STYLE C) CHILLER
(YCHA 100 – STYLE C)
TROUBLE-SHOOTING CHART
PROBLEM CAUSE SOLUTION
No display on panel 1. No 115VAC to 2T 1. Check wiring and fuse., Check emer-
Unit will not operate gency stop contacts 41 to 5
2. Faulty Wiring 2. Check wiring 2T to PSB
3. Power Supply Board (PSB) 3. Replace PSB
4. 2T defective 4. Replace 2T
5. Micro Board defective 5. Replace Micro Board (Contact the
local YORK service representative)
“A” Code on Display 1. No Flow 1. Check Chilled Liquid Flow
2. Flow Switch Installed 2. Check that Flow Switching is In-
Improperly stalled According to Manufacturer’s
Instructions.
3. Defective Flow Switch 3. Replace Flow Switch
4. Remote Stop 4. Check Cycling Devices connected to
terminals 3 & 4 of the Logic Panel
Terminal Block
5. Defective Run Permissive (R.P.) 5. Replace R.P. Relay
Relay
6. Defective Analog Input Board 6. Replace Analog Input Board (Contact
the local YORK service representative.)
}
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