York YCAL0080SC, YCAL0014SC manual Unit Switch, Display, Keypad, Battery Back-Up, Unit Status

The Microprocessor Board energizes on-board relays to output 120VAC to motor contactors, solenoid valves, etc. to control system operation.

UNIT SWITCH

A UNIT ON/OFF switch is just underneath the keypad. This switch allows the operator to turn the entire unit OFF if desired. The switch must be placed in the ON position for the chiller to operate.

DISPLAY

The 40 Character Display (2 lines of 20 characters) is a liquid crystal display used for displaying system param- eters and operator messages.

The display in conjunction with the keypad, allows the operator to display system operating parameters as well as access programmed information already in memory. The display has a lighted background for night viewing and for viewing in direct sunlight.

When a key is pressed, such as the OPER DATA key, system parameters will be displayed and will remain on the display until another key is pressed. The system parameters can be scrolled with the use of the up and down arrow keys. The display will update all informa- tion at a rate of about 2 seconds.

Display Messages may show characters indicating “greater than” (>) or “less than” (<). These characters indicate the actual values are greater than or less than the limit values which are being displayed.

FORM 150.62-NM1

KEYPAD

The 12 button non-tactile keypad allows the user to re- trieve vitals system parameters such as system pres- sures, temperatures, compressor running times and starts, option information on the chiller, and system setpoints. This data is useful for monitoring chiller op- eration, diagnosing potential problems, troubleshooting, and commissioning the chiller.

It is essential the user become familiar with the use of the keypad and display. This will allow the user to make full use of the capabilities and diagnostic features avail- able.

BATTERY BACK-UP

The Microprocessor Board contains a Real Time Clock integrated circuit chip with an internal battery back-up. The purpose of this battery back-up is to assure any programmed values (setpoints, clock, cutouts, etc.) are not lost during a power failure regardless of the time involved in a power cut or shutdown period.

UNIT STATUS

Pressing the STATUS key will enable the operator to determine current chiller operating status. The mes- sages displayed will include running status, cooling de- mand, fault status, external cycling device status, load limiting and anti-recycle/coincident timer status. The display will be a single message relating to the highest priority message as determined by the micro. Status messages fall into the categories of General Status and Fault Status.

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