Carrier 30GN040-420 Example 1 Ð Reading Alarm Codes, Example 2 Ð Reading Current Operating Modes

STATUS FUNCTION Ð This function shows the rotating display, current status of alarm and alert (diagnostic) codes, capacity stages, operating modes, chilled water set point, all measured system temperatures and pressures, superheat val- ues, pressure switch positions, analog inputs, and switch in- puts. These subfunctions are de®ned on pages 36 and 37.

(Rotating Display)

(Alarms/Alerts) Ð Alarms and alerts are messages that one or more faults have been detected. Each fault is as- signed a code number which is reported with the alarm or alert. See Table 10 for code de®nitions. The codes indicate failures that cause the unit to shut down, terminate an option (such as reset) or result in the use of a default value as set point.

Up to 10 codes can be stored at once. To view them

in sequence, press to enter the alarm/alert dis-

plays and then press to move to the individual dis-

plays. Press after a code has been displayed. The mean- ing of the code scrolls across the screen. See Example 1.

Example 1 Ð Reading Alarm Codes

KEYPAD	DISPLAY	COMMENTS
ENTRY	RESPONSE
	TUE 12:45
	LOCAL ON
	CLOCK ON	Keypad has not been used for
	13 MODE	at least 10 minutes. Alternating
	8 MODE	summary display appears on
	COOL 1	screen
	2 ALARMS
	3 MINS
	2 ALARMS	2 alarms/alerts detected
	RSAL DSB	Reset all alarms/alerts
	ALARM 9	First alarm/alert code
	COOLER LEAVING
	FLUID THERMISTOR	Explanation of alarm/alert code
	FAILURE
	ALARM 42	Second alarm/alert code.
		Cooler freeze protection
	COOLER FREEZE	Explanation of alarm/alert code
	PROTECTION

When a diagnostic (alarm or alert) code is stored in the display and the machine automatically resets, the code is de- leted. Codes for safeties which do not automatically reset are not deleted until the problem is corrected and either the machine is switched to STOP position, then back to LOCAL/ ENABLE or CCN position, or by using the keypad and dis- play module.

To reset alarms/alerts using keypad and display module:

KEYPAD	DISPLAY	COMMENTS
ENTRY	RESPONSE
	RSAL DSB	Reset all alarms/alerts
		function disabled
	RSAL ENB	Reset all alarms/alerts
		function enabled

(Modes) Ð The operating mode codes are dis- played to indicate the operating status of the unit at a given time. See Table 10.

To enter the MODES subfunction, press and

press the key to determine if more than one mode ap- plies. See Example 2 to read current mode with expansion.

Example 2 Ð Reading Current Operating Modes

KEYPAD		DISPLAY	COMMENTS
ENTRY	RESPONSE
	TUE 15:45		Keypad has not been used for at
	LOCAL ON		least 10 minutes. Rotating summary
	CLOCK ON		display appears on screen
	8 MODE
	COOL 1
	0 ALARMS
	3	MINS
	2	MODES	There are 2 modes currently in effect
	LOCAL ON		Unit is on by chiller on/off switch
	8	MODE	Temperature reset is in effect

(Stage) Ð This subfunction displays the capac-

ity stage number. See Tables 4A-4C for compressor loading sequence. To enter the STAGE subfunction, press

and press the to display the stage number.

Continue pressing for the following information:

·Number of requested stages.

·Percent of total unit capacity being utilized.

·Percent of each circuit capacity being utilized.

·Percent of total capacity available.

·Percent of capacity available in each circuit.

·Demand limit set point in effect (can be any value be- tween 0% and 100%).

·Status of each compressor relay. When a compressor is on, the number of that compressor is displayed. If a com- pressor is off, a 0 is displayed. For example: In a given circuit, if compressors 1 and 3 are running, and 2 and 4 are not running, 0301 is displayed for that circuit.

·Load/Unload factor for compressors. This factor is an in- dication of when a step of capacity is added or subtracted. Its value can range from slightly less than ±1.0 to slightly more than +1.0. When load/unload factor reaches +1.0, a compressor is added. When the load/unload factor reaches ±1.0, a compressor is subtracted. If compressor unloaders are used, at ±.6 a compressor is unloaded and at +.6, a compressor is loaded up.

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