FORM 150.40-NM20
15
YORK INTERNATIONAL
FAULT CODE DIAGNOSIS
Any time an “F” code is displayed, the compressor will
be shut down. The operator should then place the “SE-
LECT DATA DISPLAY” rotary switches to “18”. This will
cause a number from 0 to 11 to be displayed. This num-
ber can be referenced to the “Fault Codes” which tell the
operator which system failed and what the cause was.
At the time of a Fault, the microprocessor stores
operating data on the system at the instant of shut-
down. Any display selected by the operator will show
stored data. This data will remain in storage until the
SYSTEM Switch is placed in the OFF position. This
clears the microprocessor’s memory of stored data, and
any display at this time will be of current system condi-
tions. It also allows the faulted compressor to start.
Before placing the SYSTEM Switch to the OFF posi-
tion, the operator may (via the “SELECT DATA DIS-
PLAY” rotary switches) select the parameter which
caused the fault, and any other related system func-
tion, and view their magnitudes at the time of the fail-
ure. This can provide valuable trouble-shooting infor-
mation. Detailed explanations of all system safeties are
included in the “START-UP SECTION”.
After clearing the Fault, placing the SYSTEM Switch to
the ON position will cause a normal start sequence to
begin unless the problem causing the original trouble is
still causing safety thresholds to be exceeded. If this
occurs, an “F” code will then reappear.
NOTE: The trouble may not immediately show up and
the system may run for awhile.
CAUTION: Anytime the system shuts down on a Fault,
steps should be taken to find and eliminate
the cause of the problem before attempting
to restart the system.
The operator should also be aware that be-
fore the unit will display an “F” code, the sys-
tem has already shut down twice on a fault
and restarted within the last 90 minutes. This
insures that the system will not shut down
and lock out on a nuisance trip or if the sys-
tem is operating under marginal conditions.
The system will shut down instantly when a Manual
Reset Fault is sensed, but it will allow automatic restart
until it sees a total of any 3 Faults in a 90-minute pe-
riod. A 90-minute counter is started as soon as the first
Fault occurs. If 2 more faults do not occur in the next 90
minutes, the counter is reset to “0”.
After a fault, restart cannot be expected until the anti-re-
cycle timer times out. No display (“F” Code) will be indi-
cated during the first two faults except for a letter code
telling the operator the anti-recycle timer is in effect.
After 3 faults, an “F” code will be displayed and the sys-
tem will not restart. The fault can be cleared and the
compressor restarted by placing the System Off/On
Switch to the OFF position. However another fault will
shut down the system and an “F” code will be displayed.
The system will continue to shut down on every Fault
until the system runs without faulting for 90 minutes or
until power is cycled. Recycling power will reset the
counter.
SYSTEM COMPONENTS
Micro Logic Board:
The Micro Logic Board is the controller and “decision
maker” in the control panel. It looks at system inputs
via the R.P. Relay, Analog Input, and optional Digital
Input Boards and provides system control through the
Relay Output Board.
Digital Input Board: (optional)
This board allows use of optional remote chilled water
temperature select. These remote inputs are converted
to logic levels which the Micro Logic Board can under-
stand.
Analog Input Board:
This board receives analog information from transducer
(Pressure) and thermistor (temperature) inputs and
routes the data to the Micro Logic Board where it is
used to control the system.
Relay Output Board:
This board converts logic level outputs from the Micro
Logic Board to 120VAC levels used by motor contactors,
solenoids, etc. This board allows the Micro Logic Board
to control the system operation.
R.P. Relay (Run Permissive):
This Relay replaces the optional Digital Input Board.
The R.P. Relay allows connection of remote start/stop
and the flow switch contacts to the system.
Power Supply:
The power supply converts 120VAC input from 2T to
DC voltages of +5V UNREG, +5V REG, +12V
UNREG, +12V REG, and -12V UNREG for supply
voltages to operate the integrated circuitry in the
panel.
Motor Current Board and C.T.’s:
C.T.’s on the 3
φ
power wiring of the motor send AC
signals proportional to motor current to the Motor Cur-
rent Board which rectifies and filters the signal to vari-
able DC voltage (analog). This analog level is then fed
to the Analog Input Board allowing the Micro Logic Board
to monitor motor current.
(YCAH 100)
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