Carrier AquaEdge 19MV Start-Up, Operation And Maintenance Instructions Manual page 29

5. A high pressure point can be calibrated between 100 and
250 psig (689.5 and 1723.7 kPa) by attaching a regulated
pressure source (usually from a nitrogen cylinder with
high resolution pressure gage). The high pressure point
can be calibrated by accessing the appropriate transducer
parameter on the PRESSURES screen, highlighting the
parameter, 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 installed 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 indicates
that the switch is now open.
Increase the sensitivity of the flow switch by turning the adjust-
ment 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 evaporator/con-
denser pressure switches (if installed) are in need of calibration.
See Fig. 29-31 for the hydraulic status menu. With no flow the wa-
ter delta should read 0 kPa. If it does not, the value may be set to
zero using PRESSURE SENSOR CALIB located in the Mainte-
nance Menu. See Fig. 32 for the pressure sensor calibration menu.
High end calibration is not necessary. The water temperature sen-
sors should also be calibrated during the commissioning of the
chiller. The goal is to have the entering/leaving water temperature
sensors displaying the same value when water is flowing and the
chiller is not in operation.
Fig. 29 — Hydraulic Status Menu, Page 1
Fig. 30 — Hydraulic Status Menu, Page 2
Fig. 31 — Hydraulic Status Menu, Page 3
Fig. 32 — Pressure Sensor Calibration Menu
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