Carrier XRV, 19XR specifications Variable Frequency Drive VFD Starter Internal View

ENTER

OPTIONAL

METER

PACKAGE

	RUNNING	AUTO	Forward
SPEED		MAN	Reverse
VOLTS	REMOTE
AMPS	JOG	PROGRAM	RUN
Hz	AUTO		JOB
Kw	FORWARD
TORQUE	REVERSE	ENTER
Password	PROGRAM

MANUAL RESET

Fig. 7 — Variable Frequency Drive (VFD)

				+ DC BUS BAR
				MEASUREMENT
				- POINT
INTEGRATED
STARTER
MODULE
(ISM)
				INITIAL DC BUS
				MEASUREMENT
				POINT
OIL PUMP				+ DANGER -
DISCONNECT				HIGH VOLTAGE
CONTROL				AUTO Forward
		SPEED	RUNNING	MAN Reverse
		VOLTS	REMOTE
		AMPS	JOG	RUN
AND OIL		Hz	AUTO	JOB
	LINE	Kw	FORWARD
		TORQUE REVERSE		ENTER
		Password PROGRAM
HEATER
DISCONNECT				VFD
				MODULE
	LOAD
				COOLING LINES
COMPRESSOR
MOTOR
DISCONNECT		TXV

Fig. 8 — Variable Frequency Drive (VFD) Starter Internal View

General — The 19XR hermetic centrifugal liquid chiller contains a microprocessor-based control center that monitors and controls all operations of the chiller (see Fig. 9). The microprocessor control system matches the cooling capacity of the chiller to the cooling load while providing state-of-the-art chiller protection. The system controls cooling load within the set point plus the deadband by sensing the leaving chilled water or brine temperature and regulating the inlet guide vane via a mechanically linked actuator motor. The guide vane is a vari- able flow pre-whirl assembly that controls the refrigeration ef- fect in the cooler by regulating the amount of refrigerant vapor flow into the compressor. An increase in guide vane opening increases capacity. A decrease in guide vane opening decreases capacity. The microprocessor-based control center protects the chiller by monitoring the digital and analog inputs and execut- ing capacity overrides or safety shutdowns, if required.

PIC II System Components — The chiller control system is called the PIC II (Product Integrated Control II). See Table 1. The PIC II controls the operation of the chiller by monitoring all operating conditions. The PIC II can diagnose a problem and let the operator know what the problem is and what to check. It promptly positions the guide vanes to main- tain leaving chilled water temperature. It can interface with auxiliary equipment such as pumps and cooling tower fans to turn them on when required. It continually checks all safeties to prevent any unsafe operating condition. It also regulates the oil heater while the compressor is off and regulates the hot gas by- pass valve, if installed. The PIC II controls provide critical pro- tection for the compressor motor and controls the motor starter.

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