Specifications

ManualsBrandsCarrier ManualsHousehold Appliances19XRT

Perform a Control Test — Check the safety controls

status by performing an automated control test. Access the

CONTROL TEST table and select a test to be performed

function (Table 6).

The Automated Control Test checks all outputs and inputs

for function. The compressor must be in the OFF mode to

operate the controls test. The compressor can be put in OFF

mode by pressing the STOP push-button on the CVC. Each

test asks the operator to conﬁrm the operation is occurring

and whether or not to continue. If an error occurs, the op-

erator can try to address the problem as the test is being done

or note the problem and proceed to the next test.

NOTE: Enter guide vane calibration to calibrate guide

input on CCM (Plug J4 upper terminal 9 and 10).

NOTE: If during the control test the guide vanes do not open,

verify the low pressure alarm is not active. (An active low

pressure alarm causes the guide vanes to close.)

NOTE: The oil pump test will not energize the oil pump if

cooler pressure is below –5 psig (–35 kPa).

When the control test is ﬁnished or the EXIT

softkey is

pressed, the test stops, and the CONTROL TEST menu dis-

plays. If a speciﬁc automated test procedure is not com-

pleted, access the particular control test to test the function

when ready. The CONTROL TEST menu is described in the

table below.

CCM Pressure Thermistors Check of all thermistors.

CCM Pressure Transducers Check of all transducers.

Pumps Checks operation of pump out-

puts; pumps are activated. Also

tests associated inputs such as

ﬂow or pressure.

Discrete Ouputs Activation of all on/off outputs

individually.

Guide Vane Check of the guide vane

operation.

Pumpdown/Lockout Pumpdown prevents the low re-

frigerant alarm during evacuation

so refrigerant can be removed

form the unit. Also locks the

compressor off and starts the

water pumps.

Terminate Lockout To charge refrigerant and enable

the chiller to run after pumpdown

lockout.

Guide Vane Calibration Calibrates guide vane input on

CCM.

NOTE: During any of the tests, an out-of-range reading will have an

asterisk (*) next to the reading and a message will be displayed.

COOLER CONDENSER PRESSURE TRANSDUCER AND

WATERSIDE FLOW DEVICE CALIBRATION — Cali-

bration can be checked by comparing the pressure readings

from the transducer to an accurate refrigeration gage read-

ing. These readings can be viewed or calibrated from the

HEAT_EX screen on the CVC. The transducer can be checked

and calibrated at 2 pressure points. These calibration points

are 0 psig (0 kPa) and between 25 and 250 psig (173 and

1724 kPa). To calibrate these transducers:

1. Shut down the compressor, cooler, and condenser pumps.

NOTE: There should be no ﬂow through the heat

exchangers.

2. Disconnect the transducer in question from its Schrader

ﬁtting for cooler or condenser transducer calibration. For

oil pressure or ﬂow device calibration keep transducer in

place.

NOTE: If the cooler or condenser vessels are at 0 psig

(0 kPa) or are open to atmospheric pressure, the trans-

ducers can be calibrated for zero without removing the

transducer from the vessel.

3. Access the HEAT_EX screen and view the particular

transducer reading (the EVAPORATOR PRESSURE or

CONDENSER PRESSURE parameter on the HEAT_EX

screen). To calibrate oil pressure or waterside ﬂow de-

vice, view the particular reading (CHILLED WATER DELTA

P and CONDENSER WATER DELTA P on the HEAT_EX

screen, and OIL PUMP DELTA P on the COMPRESS

screen). It should read 0 psi (0 kPa). If the reading is not

0 psi (0 kPa), but within ± 5 psi (35 kPa), the value may

be set to zero by pressing the SELECT

softkey while

the appropriate transducer parameter is highlighted on the

CVC screen. Then press the ENTER

softkey. The value

will now go to zero. No high end calibration is necessary

for OIL PUMP DELTA P or ﬂow devices.

If the transducer value is not within the calibration range,

the transducer returns to the original reading. If the pres-

sure is within the allowed range (noted above), check the

voltage ratio of the transducer. To obtain the voltage ra-

tio, divide the voltage (dc) input from the transducer by

the supply voltage signal (displayed in CONTROL TEST

menu in the CCM PRESSURE TRANSDUCERS screen)

or measure across the positive (+ red) and negative

(− black) leads of the transducer. For example, the con-

denser transducer voltage input is measured at CCM ter-

minals J2-4 and J2-5. The voltage ratio must be between

0.80 and 0.11 for the software to allow calibration. Pres-

surize the transducer until the ratio is within range. Then

attempt calibration again.

4. A high pressure point can also be calibrated between 25

and 250 psig (172.4 and 1723.7 kPa) by attaching a regu-

lated 250 psig (1724 kPa) pressure (usually from

a nitrogen cylinder). The high pressure point can be cali-

brated by accessing the appropriate transducer parameter

on the HEAT_EX screen, highlighting the parameter, press-

ing the SELECT

softkey, and then using the

INCREASE

or DECREASE softkeys to adjust the

value to the exact pressure on the refrigerant gage. Press

the ENTER

softkey to ﬁnish the calibration. Pressures

at high altitude locations must be compensated for, so the

chiller temperature/pressure relationship is correct.

The PIC II does not allow calibration if the transducer is

too far out of calibration. In this case, a new transducer must

be installed and re-calibrated.

Check Optional Pumpout System Controls and

Compressor —

Controls include an on/off switch, a 3-amp

fuse, the compressor overloads, an internal thermostat, a com-

pressor contactor, and a refrigerant high pressure cutout.

The high pressure cutout is factory set to open at 161 psig

(1110 kPa) and reset at 130 psig (896 kPa). Ensure the water-

cooled condenser has been connected. Loosen the

compressor holddown bolts to allow free spring travel. Open

the compressor suction and discharge the service valves. En-

sure oil is visible in the compressor sight glass. Add oil if

necessary.

See the Pumpout and Refrigerant Transfer Procedures and

Optional Pumpout System Maintenance sections, pages 63

and 70, for details on the transfer of refrigerant, oil speci-

ﬁcations, etc.

High Altitude Locations — Because the chiller is ini-

tially calibrated at sea level, it is necessary to recalibrate

the pressure transducers if the chiller has been moved to a

high altitude location. See the calibration procedure in the

Troubleshooting Guide section.