Carrier HS070-160 manual Keyboard Display Comments Entry Response

	KEYBOARD			DISPLAY		COMMENTS
	ENTRY		I RESPONSE
	3	TEST
y$.	q	u		COMP		Factory field test of compressors
						subfunction of test function
		ENTR		CAM	OFF	Circuit A, compressor 1 test
	q			CA1 ON		Pressing ENTR starts the test; when the
						compressor should be running the
		+	I			display shows CA1 on
				CAM	OFF	If the test is allowed to time out, the
	q					display will show CA1 o f f
				C A 2	O F F	Pressing the down arrow key advances
						the system to circuit A, compressor 2 test
				END TEST		If no other test is desired, exit quick test

Refer to Fig. 5,6 and 7 for specific control wiring. Each module in a panel is numbered ( I, 2,3,4...). Each terminal strip is labeled (52, 53, J4...). The terminal strip on the machine schematic combines the module and strip numbers. For example, 2JJ is terminal strip 53 o n module 2. The module numbers can be found on the com- ponent arrangement label.

T h e m (;;;;I subfunction checks the thermistor and

switch inputs. The thermistor tests display the tempera- ture that the thermistor is reading. If the display and the actual temperature do not match, the thermistor and the input channel can each be checked.

To check the thermistor, disconnect its leads from the PSI0 terminal (the entire connector can be pulled from the PSI0 by pulling the connector to the left). Read the resistance of the thermistor, then find the corresponding temperature in Table 8.

This temperature should match the actual temperature to which the thermistor is exposed.

The thermistor can be checked while connected to the

processor by measuring the voltage across its terminals and finding the corresponding temperature in Table 8. This method can only be used if it is certain that the processor circuits are putting out the correct voltage. If there is any doubt, the thermistor should be checked by the resistance method.

The input channel can be tested by removing the

thermistor from the terminals and attaching a fixed resistor with a value between 40,000 ohms and 400 ohms. Refer to Table 8 and find the temperature that cor- responds to that resistance; this temperature should appear in the Quick Test display.

Loss of charge and oil pressure switch tests show LOW if the switch is open and NRM or SAFE if the switch is closed. The input channel can be tested by disconnecting the switch and using a jumper to simulate a closed or open circuit. (See Fig. 5.)

Note that the switch is read by the processor period- ically, not continuously. When the switch position is changed, it may take a few seconds before the display changes.

T h e [q Fi subfunction will energize the control

outputs except for the compressor control outputs. (See Fig. 6.)

The liquid line solenoid and unloader solenoid tests

will energize the output when ENTR is pressed. It will cl

remain energized until either the J key is pressed or 0

10 minutes have elapsed. When the processor energizes the output reiay it will display the word ON on the right side of the display.

The EXV open and close tests drive the EXV fully open or fully closed. See The EXV Checkout Procedure for

more information. The display will read either zero steps open or 760 steps open.

T h e 14 I;;;;] subfunction energizes the compressor

control relays for 10 seconds and displays the compressor status feedback.

The liquid line solenoid in the same circuit will ener- gize for 10 seconds and the EXV will open 180 steps, then close.

When control power reaches the compressor control relay it also reaches the feedback terminal on terminal strip 233 (see Fig. 7). When this occurs the display will

switch from OFF to UN. If the display changes but the compressor does not start, check the control relay, con-

tactor, compressor circuit breaker, interconnecting wiring, and the compressor motor.

If the display does not change, check the discharge gas thermostat, high-pressure switch, condenser fan overload (on 30HS, if used), continuity across the DSIO terminals and interconnecting wiring.

To protect the compressors from repeated cycling, a delay of one minute is required before the same com- pressor is retested.

The 4 TEST subfunctions take the unit out of the Quick Testqmodea. Press 14 H and the display will

show EKD TEST; press ENS and the display blinks and

cl

then shows END TEST again.

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