Brochure

Bulletin 40-10 – Page 31
1. diagnosis — Make certain that a
motor burnout has actually occurred
by running the proper electrical tests.
Determine the severity of the burnout
by analyzing the acid content of the
lubricant from the burned out com-
pressor. This can be done on the job
with a TA-1 One Time Acid Test Kit.
Note the color of the lubricant, the
smell of the refrigerant, and if carbon
deposits are present in the suction
line.
2. plan the procedUre — Consider
the following factors: If the lubri-
cant is not acidic and none of the
other indications of severe burnout
are present, then the system can be
classified as a “mild burnout” and
cleaned up accordingly. Under these
circumstances, it is easier to save the
refrigerant. If a lubricant sample is
desired for checking the progress of
the clean-up, then a trap should be
installed in the suction line (see Form
40-141). A semi-hermetic compressor
can be examined and cleaned by hav-
ing the head removed. A heat pump
system will frequently require replac-
ing the 4-way valve, or other special
precautions. Systems with a critical
charge must have the charge adjusted
due to the added volume in the
oversized filter-drier that is normally
installed in the liquid line.
3. mild BUrn-oUt — If the analysis
of the lubricant shows no acidity,
then the system can be classified
as a mild burnout, and cleaned up
simply by installing an oversized
Catch-All Filter-Drier in the liquid
line. If the lubricant is not analyzed,
and the other factors indicate some
doubt, then the burnout should be
considered severe and cleaned up as
described below.
caUtion — Acid burns can result
from touching the sludge in the
burned out compressor. Rubber
gloves should be worn when handling
contaminated parts.
4. severe BUrnoUts — These sys-
tems should be cleaned using the
suction line filter-drier method. The
refrigerant in the system can be saved,
and must be removed using refriger-
ant recovery/recycling equipment.
The exact method chosen depends
upon the availability of shutoff valves,
the amount of charge, and the other
equipment available. See the section
on “Saving the Refrigerant.”
5. Remove the burned out compressor
and install the new compressor.
6. Install a Catch-All Suction Line Filter-
Drier or RSF shell (selected from
pages 34 and 35) ahead of the new
compressor. The access valve on the
drier permits the pressure drop to be
checked by installing gauges on the
access valve and at the gauge port on
the suction service valve. For systems
without service valves, install a line
tap valve downstream of the Catch-All
Filter-Drier for the second connection.
7. Remove the liquid line drier and
install an oversized Catch-All (one
size larger than the normal selec-
tion size). Check the expansion
valve and other controls to see if
cleaning or replacement is required.
Install a See•All Moisture and Liquid
Indicator.
8. Evacuate the system according to the
manufacturer’s recommendations.
Normally this will include the use
of a high vacuum pump and a low
vacuum micron gauge for measuring
the vacuum obtained.
9. Recharge the system through the
access valve on the suction line filter-
drier. Then start the system according
to the manufacturer’s instructions.
10. The use of a Catch-All Filter-Drier
installed permanently in the suc-
tion line permits the clean-up of a
small system to be completed with
one service call. The pressure drop
across the suction line filter-drier
should be measured during the first
hour’s operation. If the pressure drop
becomes excessive, then the suction
line filter-drier should be replaced. If
the equipment manufacturer’s rec-
ommendations are not available, the
following maximum pressure drop
levels are suggested. See table below.
11. In 24 hours take a lubricant sample.
Observe the color and test for acid-
ity. If the lubricant is dirty or acidic,
Clean-Up Procedure
replace the suction line and liquid
line filter-driers.
In two weeks re-check the color
and acidity of the lubricant to see
if another change of filter-driers is
necessary. It may also be desirable to
change the lubricant in the compres-
sor. Before the job is complete, it is
essential that the lubricant be clean
and acid-free.
saving the refrigerant — The
refrigerant is not damaged by the burn-
out, and can be reused, provided the
contaminants are removed. When a
mild burnout has occurred on a system
with service valves, the refrigerant can
be saved by closing the valves and trap-
ping the refrigerant in the system, while
changing the compressor. The system
can then be pumped down with the new
compressor to save the refrigerant while
installing an oversized Catch-All Filter-
Drier in the liquid line.
If a severe burnout has occurred, the
above procedure might damage the new
compressor. Therefore, it is preferred that
the refrigerant be removed from the sys-
tem for reclamation. If no service valves
are available then the refrigerant must
be removed from the system. Recovery,
recycling or reclamation of the refrigerant
must be performed in accordance with
EPA regulations.
Sporlan recommends the use of our HH
style cores for cleaning up all systems
after a hermetic motor burnout. These
cores contain a desiccant mix that is
suitable for removing all types of system
contaminants. Form 40-109 is available
for selection recommendations on suc-
tion line filter-driers. Information on
cleaning up centrifugal systems is given in
Bulletin 240-10-3. Information on clean-
up after a hermetic motor burnout is also
given in Section 91 of the SAM Manual
published by the Refrigeration Service
Engineers Society.
SYSTEM
PERMANENT INSTALLATION TEMPORARY INSTALLATION
REFRIGERANT
22, 404A, 407C,
410A, 502, & 507
12 & 134a
22, 404A, 407C,
410A, 502, & 507
12 & 134a
Air Conditioning 3 (0.21) 2 (0.14) 8 (0.55) 6 (0.41)
Commercial 2 (0.14) 1-1/2 (0.10) 4 (0.28) 3 (0.21)
Low Temperature 1 (0.07) 1/2 (0.03) 2 (0.14) 1 (0.07)
Suction Line Filter-Drier Maximum Recommended Pressure Drop – psi (bar)