York YK M3 M3 G4 operation manual System Shutdown Messages

at 265 PSIG (R-22); 180 PSIG (R-134a). When the con- denser pressure falls to 245 PSIG (R-22); 160 PSIG (R-134a), the vanes will be permitted to open.

SYSTEM RUN – PRESSURE STATUS

Displayed when the chiller is running. It instructs the operator to press the STATUS key, whereupon one of the following messages will be displayed:

•WARNING: COND OR EVAP TRANSDUCER ERROR

Indicates a probable condenser or evaporator trans- ducer problem, because the output is unreasonable. The microprocessor arrives at this conclusion by subtracting the evaporator transducer output from the condenser transducer output. The result must be zero or some positive number. If the result is a nega- tive number, it concludes that there is a probable condenser or evaporator transducer problem. This function is inhibited for the first 10 minutes of chiller run-time, and is checked every 10 minutes thereaf- ter. Message is reset by pressing the WARNING RE- SET key in the Service mode.

NOTE: If the STATUS key is arbitrarily pressed, with- out the operator being prompted by the PRESS STATUS message, the following message shall be displayed.

NO MALFUNCTION DETECTED

WARNING – REFRIGERANT LEVEL OUT OF RANGE

Displayed when the refrigerant level sensor output goes to > 4.4VDC. While this is displayed, the variable ori- fice is driven open until the level is within range. This message is automatically cleared when output is within range.

SYSTEM RUN – LEAVING TEMP CONTROL

Displayed while the chiller is running. Indicates that the pre-rotation vanes are being controlled by the leaving chilled water temperature (LCWT). This is the normal mode of chiller operation. Thus, if the LCWT is above the setpoint, but pulling down rapidly, the vanes will pulse closed as the LCW nears the setpoint.

SYSTEM READY TO START

Indicates that the system is not running, but will start upon application of a start signal.

SYSTEM SHUTDOWN – PRESS STATUS

Displayed when chiller is shut down on a cycling shut- down, safety shutdown (operator must move the COM- PRESSOR switch to STOP/RESET in order to restart) or operator-initiated shutdown (within 30 minutes of

initial start-up). The status message consists of the day and time of shutdown, cause of shutdown, and type of restart required. Upon pressing STATUS key, System Shutdown Message will be displayed for 2 sec- onds and then return to

SYSTEM SHUTDOWN – PRESS STATUS

Display can be held indefinitely by depressing DIS- PLAY key. For examples of System Shutdown Mes- sages, see below.

SYSTEM SHUTDOWN MESSAGES

Day of Week	Cause of Shutdown
Time of Day	Type of Restart
MON 10:00 AM – LOW	WATER TEMP – AUTOSTART

Chiller was shut down on Monday at 10:00 AM be- cause the LCWT has decreased to a value that is 4°F below the operator-programmed chilled liquid tempera- ture setpoint. However, if the setpoint is less than 40°F, the chiller will always shut down at 36°F. Further, if the chiller is running and the setpoint is changed, the (Low Water Temperature) cutout will be 36°F for 10 minutes in order to eliminate nuisance trips. Finally, for brine chilling applications, the LWT cutout is always 4°F be- low the setpoint. (The water jumper on the Micro Board must be removed for a brine unit.)

MON XX:XX AM – FLOW SWITCH – AUTOSTART

Chiller is shut down because a chilled-liquid flow switch has opened. The flow switch must open for a minimum of 2 seconds in order to cause a shutdown. The flow switch is checked 25 seconds into “Start Sequence Initiated” and continuously thereafter.

MON XX:XX AM – SYSTEM CYCLING – AUTOSTART

A remote command (computer relay contact or manual switch) connected to the Remote/Local cycling input of the digital input board has shut down the chiller.

MON XX:XX AM – MULTI UNIT CYCLING – AUTOSTART

Lead/Lag sequence control accessory has shut down the chiller.

MON XX:XX AM – POWER FAILURE – AUTOSTART

The chiller is shut down because there has been a power interruption or failure. The chiller will automati- cally restart when power is restored. This message

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