Chiller Dehydration; Inspect Water Piping; Check Optional Pumpout Compressor; Water Piping - Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual

Chiller Dehydration —
the chiller has been open for a considerable period of time, if
the chiller is known to contain moisture, or if there has been a
complete loss of chiller holding charge or refrigerant pressure.
Do not start or megohm-test the compressor motor or oil
pump motor, even for a rotation check, if the chiller is
under dehydration vacuum. Insulation breakdown and
severe damage may result.
Dehydration can be done at room temperatures. Using a
cold trap (Fig. 32) may substantially reduce the time required
to complete the dehydration. The higher the room temperature,
the faster dehydration takes place. At low room temperatures, a
very deep vacuum is required to boil off any moisture. If low
ambient temperatures are involved, contact a qualified service
representative for the dehydration techniques required.
Perform dehydration as follows:
1. Connect a high capacity vacuum pump (5 cfm [.002 m
or larger is recommended) to the refrigerant charging
valve (Fig. 2). Tubing from the pump to the chiller should
be as short in length and as large in diameter as possible to
provide least resistance to gas flow.
2. Use an absolute pressure manometer or a wet bulb
vacuum indicator to measure the vacuum. Open the
shutoff valve to the vacuum indicator only when taking a
reading. Leave the valve open for 3 minutes to allow the
indicator vacuum to equalize with the chiller vacuum.
3. If the entire chiller is to be dehydrated, open all isolation
valves (if present).
4. With the chiller ambient temperature at 60 F (15.6 C) or
higher, operate the vacuum pump until the manometer
reads 29.8 in. Hg vac, ref 30 in. bar. (0.1 psia)
(–100.61 kPa) or a vacuum indicator reads 35 F (1.7 C).
Operate the pump an additional 2 hours.
Do not apply a greater vacuum than 29.82 in. Hg vac
(757.4 mm Hg) or go below 33 F (.56 C) on the wet bulb
vacuum indicator. At this temperature and pressure,
isolated pockets of moisture can turn into ice. The slow
rate of evaporation (sublimation) of ice at these low
temperatures and pressures greatly increases dehydration
time.
5. Valve off the vacuum pump, stop the pump, and record
the instrument reading.
6. After a 2-hour wait, take another instrument reading. If
the reading has not changed, dehydration is complete. If
the reading indicates vacuum loss, repeat Steps 4 and 5.
7. If the reading continues to change after several attempts,
perform a leak test up to the maximum 160 psig
(1103 kPa) pressure. Locate and repair the leak, and
repeat dehydration.
Inspect Water Piping —
vided in the certified drawings. Inspect the piping to the cooler
and condenser. Be sure that the flow directions are correct and
that all piping specifications have been met.
Dehydration is recommended if
Refer to piping diagrams pro-
Fig. 32 — Dehydration Cold Trap
Piping systems must be properly vented with no stress on
waterbox nozzles and covers. Water flows through the cooler
and condenser must meet job requirements. Measure the
pressure drop across the cooler and the condenser.
Water must be within design limits, clean, and treated to
3 /s]
ensure proper chiller performance and reduce the potential
of tube damage due to corrosion, scaling, or erosion.
Carrier assumes no responsibility for chiller damage result-
ing from untreated or improperly treated water.
Check Optional Pumpout Compressor Water
If the optional pumpout storage tank and/or
Piping —
pumpout system are installed, check to ensure the pumpout
condenser water has been piped in. Check for field-supplied
shutoff valves and controls as specified in the job data. Check
for refrigerant leaks on field-installed piping. See Fig. 30
and 31.
Check Relief Valves —
been piped to the outdoors in compliance with the latest edition
of ANSI/ASHRAE Standard 15 and applicable local safety
codes. Piping connections must allow for access to the valve
mechanism for periodic inspection and leak testing.
The 19XRV relief valves are set to relieve at the 185 psig
(1275 kPa) chiller design pressure.
Identify the VFD —
PWM (Pulse Width Modulated), liquid-cooled drive that
provides vector and general purpose regulation for a wide
range of applications. Identify the drive from the Drive Part
Number on the drive's nameplate (Fig. 33) and the model
number matrix in (Fig. 34).
The VFD is designed to operate in the following environ-
mental conditions:
CONDITION
Ambient Temperature
(outside NEMA 1 enclosure)
Storage Temperature
(ambient)
Humidity
61
a19-661
Be sure the relief valves have
The LiquiFlo™ 2.0 AC drive is a
SPECIFICATION
32 to 122 F (0 to 50 C)
-40 to 149 F (-40 to 65 C)
5% to 95%
(non-condensing)