Carrier 30H - Manual (Page 6)

Check Refrigerant Charge
1MP(.)R'1 \N T; Do not t>pi;n liquid \al\t' or
«-•omprcssor ciisdniiiie \al\o uinil it is deter­
mined that there is a charge in the remainder of
the system. .1 ¡h‘.sin\i- /ircs'.urc u;// induuh' a
iharj^f m ¡hi' s i v / i v / /
The units are shipped with a full refrigerant
charge (see Table 2). However, if it is necessary to
add refrigerant, the unit should be operated for
some time at full capacity and then charge can be
added until the sight glass is clear of bubbles. For
maximum liquid subcooling, the liquid level should
be up to the liquid level test cock located on the
shell, near the end, of each tower condenser. This
usually
requires additional refrigerant charge
beyond the amount to clear the sight glass (see
LIQUID CHARGING METHOD).
If there is no refrigerant vapor pressure in the
system, the entire system must be leak tested. After
repair of leaks, the system must be evacuated before
recharging.
See Standard Service Techniques
Manual, Chapter 1, Refrigerants, for leak testing,
evacuation and charging procedures.
C.M.' nON; When adjusting rdrigerant charge.
Circulate water thru the condenser and cooler at
ail times to prevent frec/ing. Frec/ing damage is
considered abuse and is not covered by Carrier
warrants.
The liquid charging method is recommended for
complete charging or when additional charge is
required.
LIQUID CHARGING METHOD
C.\U i'lON; Be careful not to overcharge s\s-
tem. Oserchaigmg results in higher discharge
pressure with higher cooling water consurnp-
tion, possible compressor damage, higher power
consumption.
Charge thru I / 4-in. flare connection on liquid line
shutoff valve. Never charge liquid into the low-
pressure side of the 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 58 psi for
R-22 (32 F). Invert refrigerant cylinder so that
liquid refrigerant will be charged.
5. a. For complete charge, see “Charging” in
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
cylinder cannot be weighed, or for adding
refrigerant, follow the procedure Charging
By Sight Glass in the manual.
6. To ensure maximum subcooler performance,
check liquid level in tower condensers by means
of test cock located on each condenser shell near
right end tube sheet. Liquid discharge from test
cock indicates fully charged subcooler.
Check Oil Charge — All units are factory charged
with oil. If oil is visible in sight glass, check the 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 erankcase
! / 8 to 3/ 8^ of bull’s-eye during steady operation. To
add or remove oil, see Standard Service Techniques
Manual, Chapter 1, Refrigerants.
Use only Carrier approved compressor oil. Do
not reuse drained oil or use any oil that has been
exposed to atmosphere.
Approved compressor oils:
Sun Oil Co. Suniso 3GS
Texaco, Inc. Capella BI
E.I. DuPont Co. DuPont Synthetic Refrig­
eration Oil, 150 SSU only
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 diseharge 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 the oil
level.
TO REMOVE OIL
Pump down eompressor to 2 psig. Close suetion
and discharge valves. Loosen the 1/4-in. pipe plug
in compressor base and allow the oil to seep out
past the threads of the plug.
The crankcase will be
under slight pressure. Be careful not to remove the
plug; the entire oil charge may be lost. Small
amounts of oil can be removed thru oil pump dis­
charge connection while compressor is running.
START-UP AND OPERATION CHECKS
Start-up should be performed only under super­
vision of experienced refrigeration mechanic. Be
sure crankcase heaters have been energized for 24
hours.
1. 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
equipment eonneeted to chiller.
3. Start unit by firmly pushing ON button.
4. Check all controls for proper operation.