York YCAS0130 manual System Switches OFF, Anti-Recycle Timers, Anti-Coincidence Timers

System Switches OFF:

S Y S	# 1	S Y S	S W I T C H	O F F
S Y S	# 2	S Y S	S W I T C H	O F F

This message indicates that the system switch on the Microprocessor Board for the respective system is in the OFF position. A system can only run if the system switch is in the ON position. The switch for System 1 and System 2 should normally be in the ON position for all models. See Section 1.11, Figure 46, page 130 for the location of the system switches.

Anti-Recycle Timers:

S Y S	#	A R	T	I M E R	1 0	S
S Y S	#	A R	T	I M E R	1 2 0	S

The anti-recycle timer message shows the amount of time remaining before a compressor can be called to restart. The 300 - 600 sec. programmable timers begin timing when a compressor starts, although a minimum of two minutes must always elapse after a compressor shuts down, before it may again restart. If a power failure occurs, the anti-recycle timers will reset to 120 seconds after power is restored. The purpose of the timer is to allow for motor cooling to dissipate the heat generated by inrush current at start-up.

Anti-Coincidence Timers:

S Y S	#	C O M P R U N N I N G
S Y S	#	A C T I M E R 2 2 S

The anti-coincident timer guards against two or more compressors starting simultaneously. This avoids ex- cessive instantaneous starting currents. A minimum of 60 seconds between compressor starts is maintained even if demand is present and the anti-recycle timers are timed out. The display shows the time before the respective compressor can start. This display will only appear after the anti-recycle timers have timed out.

Run Permissive Contacts OPEN:

S Y S	#	N O	R U N	P E R M
S Y S	#	N O	R U N	P E R M

This display indicates that an external cycling contact and/or the flow switch connected to terminals 13 & 14 in the Logic Section of the control panel is open. Whenever the contact is open, the No Run Permissive message will be displayed and the indicated system will not run.

			FORM 201.19-NM1 (204)
System Loading Requirement:
S Y S	#	N O	C O O L L O A D
S Y S	#	N O	C O O L L O A D

This message indicates that chilled liquid temperature is below the point where the microprocessor will bring the lead system on and/or that the loading sequence has not loaded the chiller far enough to bring the lag system on. The lag system will display this message until the loading sequence is ready for the lag system to start.

M A N U A L

O V E R R I D E

If the MANUAL OVERRIDE key is pressed during a scheduled time clock shutdown, the STATUS display will display the MANUAL OVERRIDE message in- dicating that the schedule is being intentionally over- ridden. Typically MANUAL OVERRIDE is only used in an emergency. As a result, the message is a priority message and will override other STATUS messages.

2.3UNIT WARNINGS

Unit Warnings are often caused by conditions which require operator intervention to start the unit or extreme operating conditions. All setpoints and programmable values should be checked, if a chiller shutdown oc- curred, before restarting the chiller. Unit Warnings are not logged into the HISTORY BUFFER.

Low Battery Warning

! ! L O W B A T T E R Y ! !

C H E C K P R O G / S E T P / T I M E

On power-up the microprocessor will check the RTC (Real Time Clock) memory back-up battery to make sure it is still operational. Provided the battery checks out, operation will continue normally. If a check is made and the battery has failed, the microprocessor will not allow the chiller to run and the above Status message will appear.

If a low battery condition exists, the micro will restore programmed cut- outs, setpoints, and schedules to their default values.

Once a low battery condition is detected, the only way to run the chiller is to use the Manual Override key - see Section 8.7.4 page 165. This allows reprogramming of setpoints, cutouts, and schedule.

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YORK INTERNATIONAL 137