Perform A Controls Test (Quick Calibration/Quick Test) - Carrier AquaEdge 19DV Series Start-Up, Operation And Maintenance Instructions Manual

Perform a Controls Test
(Quick Calibration/Quick Test)
NOTE: The QUICK TEST screens can only be accessed when the
chiller is in STOP mode.
Check the safety controls status by performing an automated
controls test. First, perform a Quick Calibration Test (Path
Main Menu → Quick Calibration). This is required for all
modulating analog actuators. Upon successful calibration, use
Quick Test (Main Menu → Quick Test) to verify operation on
desired components. Note that this is a very useful feature for
troubleshooting. On the QUICK TEST table screen, select a
test to be performed.
The Quick Test checks all outputs and inputs for proper func-
tionality. In order to successfully proceed with the controls test,
the compressor must be off with no alarms showing, and volt-
age should be within ±10% of rating plate value. Each test asks
the operator to confirm the operation is occurring and whether
or not to continue. If an error occurs, the operator can try to ad-
dress the problem as the test is being done or note the problem
and proceed to the next test.
NOTE: The refrigerant pump test will not energize the pump if
evaporator pressure is below –13 psig (–90 kPa).
When the controls test is finished the test stops and the QUICK
TEST menu displays. If a specific automated test procedure is
not completed, access the particular control test to test the
function when ready. Disable the Quick Test feature when test-
ing is complete. For information about calibration, see the sec-
tions Checking Pressure Transducers, page 50, and High Alti-
tude Locations, page 51.
EVAPORATOR AND CONDENSER PRESSURE TRANS-
DUCER AND WATERSIDE FLOW DEVICE CALIBRATION
(Waterside Device Optional with IOB Inputs Available)
Calibration can be checked by comparing the pressure readings
from the transducer to an accurate refrigeration gage reading.
The transducer can be checked and calibrated at 2 pressure
points. These calibration points are 0 psig (0 kPa) and between
10 psig (68.9 kPa) and 30 psig (206.8 kPa). To calibrate these
transducers:
1. Shut down the compressor and the evaporator and con-
denser pumps.
NOTE: There should be no flow through the heat exchangers.
2. Disconnect the transducer in question from its Schrader
fitting for evaporator or condenser transducer calibration.
For pump pressure or bearing pressure or flow device cali-
bration keep transducer in place.
NOTE: If the evaporator or condenser vessels are at 0 psig (0 kPa)
atmospheric pressure, the transducers can be calibrated for zero
without removing the transducer from the vessel.
3. Access the PRESSURE screen from the Main Menu and
view the particular transducer reading (the evaporator
pressure, condenser pressure, economizer pressure, pump
inlet pressure, pump outlet pressure, bearing inlet pres-
sure, bearing outlet pressure).
4. To calibrate a device, view the particular reading on the
screen. It should read 0 kPa. If the reading is not 0 kPa, but
within 35 kPa, the value may be set to zero while the
appropriate transducer parameter is highlighted. The value
will now go to zero. No high end calibration is necessary
for REF PUMP DELTA P or flow devices. If the trans-
ducer value is not within the calibration range, the trans-
ducer will return to the original reading. If the pressure is
within the allowed range (noted above), check the voltage
ratio of the transducer. To obtain the voltage ratio, divide
the voltage (dc) input from the transducer by the supply
voltage signal (see Maintenance Others in Maintenance
Menu) or measure across the positive (+ red) and negative
(– black) leads of the transducer. The voltage ratio must be
between 0.80 and 0.11 for the software to allow calibra-
tion. Rotate the waterside flow pressure device from the
inlet nozzle to the outlet nozzle and repeat this step. If
rotating the waterside flow device does not allow calibra-
tion then pressurize the transducer until the ratio is within
range. Then attempt calibration again.
5. A high pressure point can be calibrated between 10 and
30 psig (68.9 and 206.8 kPa) by attaching a regulated pres-
sure source (usually from a nitrogen cylinder with high
resolution pressure gage). The high pressure point can be
calibrated by accessing the appropriate transducer parame-
ter on the PRESSURES screen, highlighting the parame-
ter, then increasing or decreasing the value to the exact
pressure on the refrigerant gage.
Pressures at high altitude locations must be compensated for,
so the chiller temperature/pressure relationship is correct. This
is set in the Service Parameters (Configuration Menu).
The PIC6 does not allow calibration if the transducer is too far
out of calibration. In this case, a new transducer must be in-
stalled and re-calibrated.
IMPORTANT: When screen display calibration is complete,
do not press Calibration Enable/Dsable since the new values
will be deleted. Values are kept by exiting the pressure sensor
table.
OPTIONAL THERMAL DISPERSION FLOW SWITCH
CALIBRATION
Set the flow through the water circuit to the minimum safe
flow that will be encountered.
Reduce the sensitivity of the switch by turning the adjustment
counter-clockwise until the yellow LED turns off. This indi-
cates that the switch is now open.
Increase the sensitivity of the flow switch by turning the ad-
justment potentiometer clockwise until the yellow LED is lit.
In case of nuisance trips at low flow, increase the sensitivity of
the switch by turning the potentiometer clockwise.
HYDRAULIC STATUS
The HYDRAULIC STATUS screen (access from the Main
Menu) provides a convenient way to detect if any of the evapo-
rator/condenser pressure switches (if installed) are in need of
calibration. See Fig. 30 for the hydraulic status menu. With no
flow the water delta should read 0 kPa. If it does not, the value
may be set to zero using PRESSURE SENSOR CALIB located
in the Maintenance Menu. See Fig. 31 for the pressure sensor
calibration menu. High end calibration is not necessary.
Fig. 30 — Hydraulic Status Menu
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