York YCAL0014SC manual Unit Controls, Unit Warning, U N I T F A U L T L O W A M B I E N T T E M P

Unit Controls

U N I T F A U L T :

L O W A M B I E N T T E M P

The Low Ambient Temp Cutout is a safety shutdown designed to protect the chiller from operating in a low ambient condition. If the outdoor ambient temperature falls below the programmable cutout, the chiller will shut down. Restart can occur when temperature rises 2°F above the cutoff.

U N I T F A U L T :

L O W L I Q U I D T E M P

The Low Leaving Chilled Liquid Temp Cutout protects the chiller form an evaporator freeze-up should the chilled liquid temperature drop below the freeze point. This situation could occur under low flow conditions or if the micro panel setpoint values are improperly pro- grammed. Anytime the leaving chilled liquid tempera- ture (water or glycol) drops below the cutout point, the chiller will shutdown. Restart can occur when chilled liquid temperature rises 2°F above the cutout.

U N I T F A U L T :

1 1 5 V A C U N D E R V O L T A G E

The Under Voltage Safety assures that the system is not operated at voltages where malfunction of the mi- croprocessor could result in system damage. When the115VAC to the micro panel drops below a certain level, a unit fault is initiated to safely shut down the unit.

Restart is allowed after the unit is fully powered again and the anti-recycle timers have finished counting down.

UNIT WARNING

The following message is not a unit safety and will not be logged to the history buffer. It is a unit warning and will not auto-restart. Operator intervention is required to allow a re-start of the chiller.

! ! L O W B A T T E R Y	! !
C H E C K P R O G / S E T P	/ O P T N

The Low Battery Warning can only occur at unit power- up. On micro panel power-up, the RTC battery is checked. If a low battery is found, all programmed setpoints, program values, options, time, schedule, and history buffers will be lost. These values will all be reset to their default values which may not be the desired operating values. Once a faulty battery is detected, the unit will be prevented from running until the PROGRAM key is pressed. Once PROGRAM is pressed the anti- recycle timers will be set to the programmed anti-re- cycle time to allow the operator time to check setpoints, program values, and options.

If a low battery is detected, it should be replaced as soon as possible. The programmed values will all be lost and the unit will be prevented from running on the next power interruption. The RTC/battery is located at U17 on the microboard.

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