Carrier 16DF013-050 - Manual (Page 37)

INITIAL START-UP
Job Data and Tools Required
• reference information and tools listed under Before Initial
Start-Up, page 32
• hydrometer(s) — specific gravity range 1.0 to 2.0
• thermometer set — range 30 to 300 F (0° to 150 C)
• liquid charging hose consisting of flexible
3 ⁄
4
-in.
(20-mm) hose connected to a 3 ft (1 m) long x 1 ⁄
2
-in.
(15 mm) pipe trimmed at a 45-degree angle at one end,
with a
1 ⁄
2
-in. MPT connector.
Follow the start-up sequence in detail and in the order
described. To ensure the quick, even formation of a solid
protective film on the internal steel surfaces, and par-
ticularly in the high-temperature direct fired generator,
the burner must be operated at the full firing rate for an
extended period within one day after the refrigerant and
lithium bromide have been charged into the machine. A
vacuum pump also must be in operation during the en-
tire charging and start-up period. This protective film is
required to prevent local corrosion in the machine dur-
ing normal operation.
Also do not apply power to hermetic pumps or at-
tempt to start the machine until it has been charged with
lithium bromide solution and refrigerant. The pumps will
be severely damaged if rotated without the full liquid
charge.
Noncondensable Evacuation — Connect a vacuum
pump with an oil trap to the absorber evacuation valve as
described in the Maintenance Procedures section, page 46.
A cold trap should be used to improve the pump capacity
and to minimize the need for frequent replacement of the
pump oil charge because of water vapor contamination. The
suction vacuum of the pump should be checked with a deep
vacuum gage both initially and periodically while the pump
is in use to be sure that it is below 0.1 in. Hg (2.5 mm Hg)
absolute.
The vacuum pump must be in operation continuously while
the refrigerant and lithium bromide solution are charged into
the machine. The evacuation should then be continued for at
least one additional hour to be sure any air which might have
entered the machine has been removed. The refrigerant and
solution pumps must remain off to prevent damage to them
until the liquids have been fully charged, but then must be
operated during the evacuation period following the charg-
ing to separate any entrained air from the liquids.
The vacuum pump also must be used during the initial
high fire run in period, typically lasting 3 to 5 days. This is
to remove noncondensables which are generated during ini-
tial start-up, occasionally at a rate greater than can be trans-
ferred by the machine’s hermetic purge alone.
Solution and Refrigerant Charging
Lithium bromide and its lithium chromate inhibitor can
irritate the skin and eyes. Wash off any solution with
soap and water. If solution enters the eye, wash the eye
with fresh water and consult a physician immediately.
Lithium bromide is a strong salt solution; do not syphon
by mouth.
Liquid materials that are added to lithium bromide
solution such as lithium hydroxide, hydrobromic acid,
octyl alcohol, and lithium chromate inhibitor, are clas-
sified as hazardous materials. These materials, and any
lithium bromide solution they are in, must be handled in
accordance with Occupational Safety and Health Ad-
ministration and Environmental Protection Agency
regulations.
HANDLING LITHIUM BROMIDE SOLUTION — Solu-
tions of lithium bromide and water are nontoxic, nonflam-
mable, nonexplosive, and can easily be handled in open con-
tainers. The solution is chemically stable and does not undergo
any appreciable change in properties even after years of use
in the absorption machine. Its general chemical properties
are similar to those of table salt.
IMPORTANT: Because lithium bromide salt can cor-
rode metal in the presence of air, wipe off any solution
spilled on metal parts or tools and rinse the part with
fresh water as soon as possible. After rinsing, coat the
tools with a light film of oil to prevent rust. After emp-
tying metal containers of solution, rinse the container
with fresh water to prevent corrosion. Immediately wipe
or flush the floor if lithium bromide or octyl alcohol is
spilled on it.
Lithium bromide for absorption machine use should
be kept only in the original container or in a com-
pletely clean container. Used lithium bromide solution
should be disposed of by a reputable chemical dis-
posal company.
The total charge of lithium bromide solution and distilled
or softened water must be available on site before any is charged
into the machine. This is to be sure the charging process and
initial start-up can continue uninterrupted. The nominal vol-
umes are shown in Table 13.
NOTE: The 16DF machine uses 55% concentration of lithium
bromide solution, with different properties than the 53% con-
centration
solution used in single-effect absorption
chillers.
37