Open Refrigerant Valves; Remove Compressor Hold-Down Bolts; Compressor Lubrication; Charging Procedure 50Bb024 And 9Ab - Carrier 50AH024 Installation, Start-Up And Service Instructions Manual

Carrier
INSTALLATION
50B
BA,BB,BC024
TABLE 7 - LINE SIZES
System
Refrigerant
Disch.
Line
Connection
Liquid
Line
Connection
1
1
!
Recommended Line Sizes
Linear Feet Piping
20 40 60
Hot
Gas
Liquid
Hot
Gas Liquid
Hot 1
Gas Liquid
Each
System 22 7/8"
1
5/8"
7/8 5/8
l
1 1/8 ! 5/8
!
. -I
1 1/8
3/4
13. REFRIGERANT CHARGE 16. COMPRESSOR LUBRICATION
In the water cooled units each system contains 17
pounds of refrigerant, giving a total of 34 pounds for
each unit.
The condenserless units are shipped from the factory
with a 2-1/2 pound holding charge in each system.
The operating charge of the base unit only is 7 pounds
for each circuit or a total of 14 pounds in each unit.
To this, add the charge requirements of the refrig¬
erant lines, condensers and receivers (when used).
If used with other refrigerant, consult your Applica¬
tion Engineering Data for information.
14. OPEN REFRIGERANT VALVES
Before putting the unit into operation, open the
following valves:
Compressor Discharge valves on each
compressor
Compressor Suction valves on each
compressor
Liquid Line shut off valves
On air cooled units, also check the
valves on the receiver
After opening the valves, replace the valve caps and
tighten to prevent leakage around the valve packing.
15. REMOVE COMPRESSOR HOLD DOWN BOLTS
The spring mounted compressors are held rigid in
shipment by four hold bolts. After removing the bolts
the compressors should float freely upon the springs.
Save the bolts for future use by placing in a cotton
bag and tying inside the unit where they will not rat¬
tle. They should be used whenever the unit is moved
from one location to another.
No external oiling of the hermetic compressors is
required, since the compressor oil is sealed inside
the cooling system. However, the oil level at the
compressor sight glass should be checked. To check
the level, operate the unit for 20 minutes and then
shut the compressor off. The correct oil level is
between 1/2 and 3/4 of the oil sight glass.
17. CHARGING PROCEDURE 50BB024 AND 9AB
The complete refrigerant system should be evacuated
with a good vacuum pump before charging with
refrigerant. When charging, connect a cylinder of
refrigerant through a tee to a gauge to the gauge port
on the compressor service valve. Have the cylinder
in the upright position to admit vapor only. Admit
refrigerant to break the vacuum in the system. Start
the compressor and modulate the valve on the cylin¬
der to keep the suction pressure slightly under 50
psig. Charge the system until liquid refrigerant will
bleed from the liquid level check port on the receiver
and also until the sight glass is clear. *
*NOTE: If the liquid refrigerant will bleed from the
liquid level check port on the receiver but
there is still flashing at the sight glass,
there is an indication that the liquid line or
filter-drier is restricted.
Let system operate for 20 min. to balance
out and recheck the refrigerant and oil levels.
The receiver has a bleeder port at the top to bleed
non-condensables from the system. There has to be
sufficient refrigerant in the system to make a liquid
seal at the outlet of the receiver to trap the non-con¬
densable in the top of the receiver before the bleeder
port can be effective. For charging instructions
when using 09DC condensers see installation book
09DC501005.
15