Carrier 30HK - Manual (Page 7)

The ЗОН К units are shipped with a full refrigerant
charge (see Table 2). However, if it is necessary to
add refrigerant, operate the unit for some time at
full capacity and then add charge until the sight glass
is clear of bubbles. For maximum liquid subcooling,
liquid level should be up to condenser liquid level
test cock located on shell, near condenser end. This
usually
requires additional refrigerant charge
beyond amount to clear sight glass.
30HL units (condenserless) are shipped with a
holding charge only. After chiller assembly is com­
pleted in the field, system must be fully charged.
While unit is running at full capacity, add refrigerant
until sight glass is clear.
If there is no refrigerant vapor pressure in the
system, the entire system must be leak tested. After
repair of leaks, evacuate system before recharging.
See Carrier Standard Service Techniques Manual,
Chapter 1, Refrigerants, for leak testing, evacuation
and charging procedures.
CAU TION; When adjusting relrigcrant charge,
circulate water thru the condenser and cooler at
all times to prevent free/ing. Freezing damage is
considered abuse and may affect the Carrier
The liquid charging method is recommended for
complete charging or when additional charge is
required.
LIQUID CHARGING METHOD
C.'M 1 ION; Be careful nut to overcharge sys­
tem. (.)\ercharging results in higher dischaige
pres.sure wiih higher cooling water consump­
tion. possible compressor damage, and higher
power cemsumption.
Charge thru 1/4-in. flare connection on liquid
line shutoff valve. Never charge liquid into low-
pressure side of system.
1. Frontseat (close) liquid line shutoff valve.
2. Connect a refrigerant cylinder loosely to charg­
ing valve connection. Purge charging line and
tighten connections.
3. Open liquid line shutoff valve.
4. If system has been dehydrated and is under
vacuum, break vacuum with refrigerant (gas
charge). Build up system pressure to 58psi for
R-22 (32 F). Invert refrigerant cylinder so that
liquid refrigerant will be charged.
5. a. For complete charge, see Charging in Carrier
Standard Service Techniques Manual, Chap­
ter 1, Refrigerants. Follow Charging By
Weight procedure. (When charge is nearly
full, complete process by observing sight glass
for clear liquid flow.)
b. For complete charge where refrigerant cyl­
inder cannot be weighed, or for adding refrig­
erant, follow the procedure Charging By Sight
Glass in manual.
6. To ensure maximum subcooler performance on
30HK units, check liquid level in condenser by
means of test cock located on condenser shell
near right end tube sheet. Liquid discharge from
test cock indicates fully charged subcooler.
Check on Charge — All units are factory charged
with oil. If oil is visible in sight glass, check unit for
operating readiness as described in the section,
Initial Check; then start compressor. Observe level
and add oil, if required, to bring level in crankcase
1/8 to 3/8 of bull’s-eye during steady operation. To
add or remove oil, see Carrier Standard Service
Techniques Manual, Chapter 1, Refrigerants.
Use only Carrier-approved compressor oil:
Witco Chemical Co................................Suniso 3GS
lexaco, Inc........................................ Capella WF-32
Do not reuse oil that has been drained and do
not use oil that has been exposed to atmosphere.
TO ADD OIL
Close suction shutoff valve and pump down
crankcase to 2 psig (low-pressure cutout must be
bypassed with a jumper). Wait a few minutes and
repeat as needed until pressure remains at 2 psig.
Close discharge shutoff valve. Remove oil fill plug
above bull’s-eye, add oil thru plug hole and replace
plug. Reopen suction and discharge valves. Run
compressor for about 20 minutes and check oil level.
TO REMOVE OIL
Pump down compressor to 2 psig. Close suction
and discharge valves. Loosen the 1/4-in. pipe plug
in compressor base and allow oil to seep out past
plug threads. The crankcase will be under slight
pressure. Be careful not to remove plug; the entire
oil charge may he lost. Small amounts of oil can be
removed thru oil pump discharge connection while
compressor is running.
START-UP
Start-up should be performed only under super­
vision of experienced refrigeration mechanic. Be
sure crankcase heaters have been energized for
24 hours.
!. Open all system valves that may have been
closed during or after charging.
2. Check air handling equipment, chilled water and
condenser water pumps, and any other equip­
ment connected to chiller.
3. Start unit by firmly pushing ON button.
4. Check all controls for proper operation. Refer to
Check Unit Safety Devices.
5. Adjust water-regulating valve (if used) to most
economical head pressure (based on relative cost
of water and electricity). Head pressure is nor­
mally 200 to 230 psi for R-22.
1090