Specifications

84
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.
Check Optional Pumpout System Controls
and Compressor —
Controls include an on/off switch,
a 0.5-amp fuse, the compressor overloads, an internal thermo-
stat, a compressor contactor, and a refrigerant high pressure
cutout. The high pressure cutout is factory set to open at
185 psig (1275 kPa) and reset at 140 psig (965 kPa). Ensure the
water-cooled condenser has been connected. Open the com-
pressor suction and discharge the service valves. Ensure 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 90 and
99, for details on the transfer of refrigerant, oil specifications,
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 alti-
tude location. See the calibration procedure in the Trouble-
shooting Guide section.
Charge Refrigerant into Chiller
The standard 19XR chiller is shipped with the refrigerant
already charged in the vessels. However, the 19XR may be or-
dered with a nitrogen holding charge of 15 psig (103 kPa).
Evacuate the nitrogen from the entire chiller, and charge the
chiller from refrigerant cylinders.
CHILLER EQUALIZATION WITHOUT A PUMPOUT
UNIT
To equalize the pressure differential on a refrigerant isolated
19XR chiller, use the TERMINATE LOCKOUT function of
the CONTROL TEST on the SERVICE menu. This helps to
turn on pumps and advises the operator on proper procedures.
The following steps describe how to equalize refrigerant
pressure in an isolated 19XR chiller without a pumpout unit.
1. Access terminate lockout function on the CONTROL
TEST screen.
2.
3. Slowly open the refrigerant cooling isolation valve. The
chiller cooler and condenser pressures will gradually
equalize. This process takes approximately 15 minutes.
4. Once the pressures have equalized, the cooler isolation
valve, the condenser isolation valve, and the hot gas isola-
tion valve may now be opened. Refer to Fig. 43 and 44
for the location of the valves.
CHILLER EQUALIZATION WITH PUMPOUT UNIT —
The following steps describe how to equalize refrigerant pres-
sure on an isolated 19XR chiller using the pumpout unit.
1. Access the terminate lockout function on the CONTROL
TEST screen.
2.
3. Open valve 4 on the pumpout unit and open valves 1a and
1b on the chiller cooler and condenser, Fig. 43 and 44.
Slowly open valve 2 on the pumpout unit to equalize the
pressure. This process takes approximately 15 minutes.
4. Once the pressures have equalized, the discharge isola-
tion valve, cooler isolation valve, optional hot gas bypass
isolation valve, and the refrigerant isolation valve can be
opened. Close valves 1a and 1b, and all pumpout unit
valves.
The full refrigerant charge on the 19XR will vary with chill-
er components and design conditions, as indicated on the job
data specifications. An approximate charge may be determined
by adding the condenser charge to the cooler charge as listed in
Tables 16A and 16B.
Use the CONTROL TEST terminate lockout function to
monitor conditions and start the pumps.
If the chiller has been shipped with a holding charge
, the
refrigerant is added through the pumpout charging connection
(Fig. 43 and 44, valve 1b). First evacuate the nitrogen holding
charge from the chiller vessels. Charge the refrigerant as a gas
until the system pressure exceeds 35 psig (241 kPa) for HFC-
134a. After the chiller is beyond this pressure the refrigerant
should be charged as a liquid until all the recommended refrig-
erant charge has been added. The charging valve (Fig. 43 and
44, valve 7) can be used to charge liquid to the cooler if the
cooler isolation valve (11) is present and is closed. Do not
charge liquid through the linear float to the condenser.
CAUTION
The transfer, addition, or removal of refrigerant in spring
isolated chillers may place severe stress on external piping
if springs have not been blocked in both up and down
directions.
CAUTION
Always operate the condenser and chilled water pumps
during charging operations to prevent freeze-ups.
CAUTION
When equalizing refrigerant pressure on the 19XR chiller
after service work or during the initial chiller start-up, do
not use the discharge isolation valve to equalize. Either the
motor cooling isolation valve or the charging hose (con-
nected between the pumpout valves on top of the cooler
and condenser) should be used as the equalization valve.
IMPORTANT: Turn on the chilled water and con-
denser water pumps to prevent freezing.
WARNING
Whenever turning the discharge isolation valve, be sure to
reattach the valve locking device. This prevents the valve
from opening or closing during service work or during
chiller operation.
WARNING
Whenever turning the discharge isolation valve, be sure to
reattach the valve locking device. This prevents the valve
from opening or closing during service work or during
chiller operation.
CAUTION
Always operate the condenser and chilled water pumps
whenever charging, transferring, or removing refrigerant
from the chiller.
IMPORTANT: Turn on the chilled water and con-
denser water pumps to prevent freezing.