York YK M3 M3 G4 THRU YK S6 S4 J2, YK LB LB G4 THRU YK SE SC J4 operation manual

terms of minutes (to a maximum of 255). If not pro- grammed, the default value is 100% FLA for 00 min- utes. (See “Programming Systems Setpoints”, page 16.) Thus, no pull down demand limit is imposed following system start, and the % current limit setpoint is used.

CLOCK – This key displays the day of the week, time of day and calendar date. If not programmed, the default value is SUNDAY 12:00 AM 1/1/92 .

(See “Programming System Setpoints”, page 16.)

DAILY SCHEDULE – This key displays the programmed daily start and stop times, from Sunday thru Saturday plus Holiday. If desired, the Control Center can be pro- grammed to automatically start and stop the chiller as desired. This schedule will repeat on a 7-day calendar basis. If the Daily Schedule is not programmed, the de- fault value is 00:00 AM start and stop times for all days of the week and the holiday. (Note that the system will not automatically start and stop on a daily basis with these default values because 00:00 is an “Impossible” time for the Micro Board. See “Programming System Setpoints”, page 17.) Finally, one or more days in the week can be designated as a holiday (see description under HOLIDAY setpoint) and the Control Center can be programmed (usually Daily Schedule setpoint) to automatically start and stop the chiller on those days so designated. The operator can override the time clock at any time using the COMPRESSOR switch.

Note that if only a start time is entered for a particular day, the compressor will not automatically stop until a scheduled stop time is encountered on a subsequent day.

HOLIDAY – This key indicates which days in the upcom- ing week are holidays. On those designated days, the chiller will automatically start and stop via the holiday start and stop times programmed in the DAILY SCHED- ULE setpoint. It will do this one time only and the follow- ing week will revert to the normal daily schedule for that day.

REMOTE / RESET TEMP RANGE – This key displays the maximum offset of remote LCWT setpoint reset.This offset is either 10° or 20°F as programmed. When in the REMOTE mode, this value is added to the operator pro- grammed CHILLED LIQUID TEMP setpoint and the sum equals the temperature range in which the LCWT can be reset. For example, if the operator programmed CHILLED LIQUID TEMP setpoint is programmed with a value of 10°F, then the CHILLED LIQUID TEMP setpoint can be remotely reset over a range of 46°F to 56°F (46

+10 = 56). If not programmed, the default value for this parameter is 20°F.

FORM 160.49-O2

For additional information on remote LCWT reset, refer to Form 160.49-PW13.

NOTE: If an Energy Management System is interfaced to the Control Center for the purpose of remote LCWT setpoint reset, then the operator pro- grammed REMOTE RESET TEMP RANGE value determines the maximum value of tem- perature reset controlled by the Energy Man- agement System.

DATE LOGGER – This key is used when an optional printer is connected to the MicroComputer Control Cen- ter. Refer to Form 160.49-N7 for operation instructions.

SSSMOTOR CURRENT/VOLTS – This key is used on Solid State Starter applications only. Although this is a display key, it is used to program the applicable AC power line voltage range (380VAC, 400VAC, 415VAC, 440-480VAC,550-600VAC). The MicroComputer Con- trol Center uses this entry to determine the under-volt- age and overvoltage shutdown threshold. For each line voltage category, there is an undervoltage and ov- ervoltage shutdown threshold. If the AC power line volt- age exceeds these thresholds for 20 continuous sec- onds, the chiller shuts down and displays

MON 10:00 AM LOW LINE VOLTAGE

– or –

MON 10:00 AM HIGH LINE VOLTAGE

This overvoltage and undervoltage protection can be disabled. Refer to chart below:

LOW / HIGH LINE VOLTAGE TRIP / RESET VALUES

COMPRESSOR	LOW LINE VOLTAGE		HIGH LINE VOLTAGE
	OPERATING POINT		OPERATING POINT
MOTOR
SUPPLY VOLTAGE	CUTOUT-(V)	CUTIN-(V)	CUTOUT-(V)	CUTIN-(V)
RANGE – (V)
	(ON FALL)	(ON RISE)	(ON RISE)	(ON FALL)
380	305	331	415	414
400	320	349	436	435
415	335	362	454	453
440-480	370	400	524	523
550-600	460	502	655	654
Supply Voltage	NONE	0	NONE	0
Range Disabled

For security reasons, a special access code is required to program the supply voltage range.The supply voltage range is programmed at the factory and should only be changed by a service technician.

YORK INTERNATIONAL 11