Carrier 5H - Manual (Page 7)

MANUAL PUMP DOWN - The compressor maybe
controlled manually without the use ofpumpdown,
or single pumpout control, and without crankcase
heaters, provided the system is at all times under
the control of a qualified operator. The operator
will pump down the system by use of the manual
valves and will keep liquid, suction and discharge
valves closed when the machine is not operating.
This method of manual operation may be used
for any system, but is particularly applicable to
flooded systems. With flooded systems crankcase
heaters are used for short "OFF" cycle periods;
manual pumpdown is needed during extended
compressor shutdown.
Compressot' Features and Accessories
WATER-COOLED HEADS AND OIL COOLERS -
Water-cooled heads are available as accessories
on all 5F,H compressors. Water cooling in cyl­
inder heads is not necessary for any R-12, R-500
or R-502 application within the range of the ratings
shown in this publication. Water-cooled heads are
required, however, and must be used for most
R-22 applications where the compression ratio is
greater than 5.
In many cases when the operating conditions are
such that the suction gas becomes superheated and
the compression ratio is high, it is required that an
oil cooler be used on the compressor. This will
insure cooler oil temperatures thereby increasing
the life expectancy of the shaft seal. Oil cooler
packages and modified bearing heads are available
from the factory and are easily installed on all
5 Series compressors (except 5F20 and 30). The oil
coolers are field mounted. The special bearing
head is available for field installation or can be
factory mounted on special order. Refer to 5F,H
Application Ratings (5F,H-3XR) to find when oil
coolers are required.
Water flow thru compressor heads and oil
cooler must be shut off when the compressor is
not running to prevent the refrigerant vapors from
condensing at the compressor during these OFF
cycles. For this purpose a solenoid valve is rec­
ommended in the water supply line to the com­
pressor heads.
•
The values listed in Table 7 assume a water
temperature rise of 30 F. The oil cooler and
water-cooled heads must be piped in series with
the oil cooler first. Leaving water temperature
should be between 100 F and 120 F, with 120 F
being the maximum allowable temperature. The
maximum working pressure for the water-cooled
heads is 125 psi.
Table 7 - Minimum Gpm Required for Water-
Cooled Heads and/or Oil Cooler
(Based on 30 F Rise)
COMPRESSOR GPM
5F 2-3
5H (4, 6 and 8 Cylinders) 6
5H (12 Cylinders) 8
SAFETY RELIEF VALVES - All 5H compressors
are equipped with built-in safety relief valves
which are factory set to relieve from the discharge
to the suction side of the compressor at a pressure
differential of 350 psi.
Safety relief valves which relieve at a 400 psi
pressure differential are factory-installed on the
5F60 compressor but are not available with the
smaller 5F compressors.
SUCTION STRAINERS - Each 5F,H compressor
is equipped with one or two suction strainers lo­
cated in the suction manifold. On new installations,
felt filters should be used in the suction strainers
to trap out foreign material left after Installation.
After about 50 hours these felt filters must be
removed. See the 5F,H Installation Manual for
further details.
OIL SAFETY SWITCH - An oil safety switch is
provided with all compressors except the 5F20
and 5F30. This switch is optional equipment on
the 5F20 and 5F30 compressors. This switch
will shut off the compressor before high oil tem­
peratures or lack of oil causes loss of oil pres­
sure which can result in compressor failure.
As a safety feature, this switch must be reset
manually after cutout.
S U P E R S E D E S
SECTION 5F,H-1X
PAGES 1-42
DATE 11-63
SECTION
PAGE
DATE
5F,H-1XA
7
10-66