Carrier 30GN040-420 operating instructions Ð Operational and Mode Display Codes

Table 10 Ð Operational and Mode Display Codes

The operating modes are displayed by name or code num- ber, to indicate the operating status of the unit at a given time. The modes are:

CODE	DESCRIPTION
	Unit is off. LOCAL/ENABLE-STOP-CCN switch is in
LOCAL OFF	OFF position, or LOCAL/ENABLE-STOP-CCN switch
	may be in LOCAL position with external ON/OFF
	switch in OFF position.
CCN OFF	Unit is off due to CCN network command. LOCAL/
	ENABLE-STOP-CCN switch is in CCN position.
CLOCK OFF	Unit is off due to internal clock schedule. LOCAL/
	ENABLE-STOP-CCN switch is in LOCAL position.
LOCAL ON	Unit is on. LOCAL/ENABLE-STOP-CCN switch is in
	LOCAL position. If external ON/OFF switch is used,
	it will be in ON position.
CCN ON	Unit is on due to CCN command. LOCAL/ENABLE-
	STOP-CCN switch is in CCN position.
CLOCK ON	Unit is on due to internal clock schedule or occu-
	pied override function. LOCAL/ENABLE-STOP-
	CCN switch is in LOCAL/ENABLE position.
	Dual set point is in effect. In this mode, unit contin-
MODE 7	ues to run in unoccupied condition, but leaving ¯uid
	set point is automatically increased to a higher level
	(CSP2 set point is in SET function).
	Temperature reset is in effect. In this mode, unit is
	using temperature reset to adjust leaving ¯uid set
MODE 8	point upward, and unit is currently controlling to the
	modi®ed set point. The set point can be modi®ed based
	on return ¯uid, outdoor-air temperature, or space tem-
	perature.
	Demand limit is in effect. This indicates that ca-
MODE 9	pacity of unit is being limited by demand limit control
	option. Because of this limitation, unit may not
	be able to produce the desired leaving ¯uid
	temperature.
MODE 10	Flotronic™ System Manager (FSM) is controlling the
	chiller.
MODE 11	Not applicable.
	Ramp load (pulldown) limiting is in effect. In this mode,
	the rate at which leaving ¯uid temperature is dropped
MODE 12	is limited to a predetermined value to prevent com-
	pressor overloading. See CRAMP set point in the
	SET function in Table 9. The pulldown limit can be
	modi®ed, if desired, to any rate from .2 F to 2 F
	(.1° to 1° C)/minute.
	Timed override is in effect. This is a 1 to 4 hour tem-
MODE 13	porary override of the programmed schedule, forc-
	ing unit to occupied mode. Override can be imple-
	mented with unit under LOCAL/ENABLE or CCN
	control. Override expires after each use.
	Low cooler suction protection is in effect. In this mode,
	circuit capacity is not allowed to increase if cooler
	saturated suction temperature is 20° F (11° C) for
MODE 14	¯uid or 30° F (16° C) for brine or more below leaving
	¯uid temperature, and saturated suction tempera-
	ture is less than 32 F (0° C). If these conditions per-
	sist beyond 10 minutes, circuit is shut down and fault
	code 44 or 45 is displayed.
MODE 15	Water System Manager is controlling the chiller.
MODE 16	Slow change override is in effect.
MODE 17	X minute off-to-on delay is in effect.
MODE 18	Low suction superheat protection is in effect.

CCN Ð Carrier Comfort Network

(Set Point) Ð This subfunction displays leaving

¯uid temperature and leaving chilled ¯uid set point. If unit is programmed for dual set point, the chilled ¯uid set point currently in effect (either occupied or unoccupied) is displayed. If reset is in effect, the unit operates to the modi- ®ed chilled ¯uid set point. This means the leaving ¯uid tem- perature may not equal the chilled ¯uid set point. The modi®ed chilled ¯uid set point can also be displayed in the Status function. To enter the set point subfunction,

press and press to display the set point fol-

lowed by the modi®ed leaving chilled ¯uid set point and ac- tual control temperature.

(Temperature) Ð The temperature subfunction dis- plays the readings at temperature sensing thermistors.

To read a temperature, enter , then scroll to de-

sired temperature using the key. See Table 9 for the

order of readouts. This subfunction also displays the satu- rated refrigerant temperatures corresponding to the suction and discharge pressures measured by the compressor transducers.

(Pressure) Ð This subfunction displays suction,

discharge, and net oil pressure at lead compressor of each circuit of unit.

(Analog Inputs) Ð This subfunction displays

analog inputs, if any. Press , then press . The

transducer supply voltage, 4-20 mA reset signal can be dis- played. This is useful for problem diagnosis prior to using the test function.

(Discrete Inputs) Ð This subfunction displays sta-

tus (open/closed) of discrete input switch where applicable. Status of dual set point switch and demand limit switches 1 and 2 can be displayed. This is useful for problem diagnosis prior to using the test function.

(Outputs) Ð This function displays on/off sta-

tus of alarm relay, all fan relays, and chilled water pump relay. It also displays on/off status of compressor unloaders (if used). The position of each EXV (in percent open) can be displayed.

TEST FUNCTION Ð The test function operates the diag- nostic program. To initiate test function, the LOCAL/ ENABLE-STOP-CCN switch must be in STOP position.

To reach a particular test, press its subfunction number,

then scroll to desired test by pressing . Press to

start a test. Press or or to terminate or exit a

test. Pressing the key after a test has started advances

system to next test, whether current test is operating or has timed out. Once in the next step, you may start

test by pressing or advance past it by pressing .

While the unit is in test, you may leave test function and access another display or function by pressing appropriate keys. However, a component that is operating when an- other function is accessed remains operating. You must

re-enter test function and press to shut down the com-

ponent. Components with a timed operating limit time out normally even if another function is accessed.

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