Chapter 5. Attention When Repairing; How To Repair Refrigeration - Sharp S3503CVP09FX/T Service Manual

CVP09FX
CVP09FX
CHAPTER 5.
ATTENTION WHEN REPAIRING

[1] HOW TO REPAIR REFRIGERATION

Before sealed system work can be preformed a refrigerant recovery EPA and LOCALLY approved certification is required, additionally, EPA
and LOCALLY approved refrigerant recovery equipment is required.
1. Sealed system repair
Sealed system repairs should be properly diagnosed before entering
into a repair of the system.
It is important to follow proper procedures when doing a system repair
for safety reasons and that the repair will result in a restoration of the
system to proper factory standards.
2. Safety reminders
1) Do not heat any system component with an open flame for any rea-
son.
2) Do not solder until you are sure that all refrigerant has been
removed from the system.
3) Do not heat the charging cylinder with an open flame. Use warm
water only and do not exceed 125°F (not too hot to keep your hand
in.)
4) Do not over fill any charging cylinders, as they could explode when
over filled.
5) Use proper wrenches.
6) Use safety goggles when working with refrigerants.
7) Keep a fire extinguisher within easy reach.
8) Watch flame direction when soldering so as not to burn clothing,
wiring or other components.
9) Solder in a well ventilated area. If a high concentration of freon is
present, an open flame will create phosgene gas which can be
harmful.
3. Proper soldering
Joint clearances should be maintained so that the brazing alloy will
flow between the closely mated surfaces rather than forming large fil-
lets.
This films make the strongest joints, capillary attraction also work best
with close tolerance.
The best clearance is between 0.01" to 0.03", the amount of lap will be
approximately 3/8" depending on the swaging tool used.
Joint Clearance.
GOOD FIT
PROPER
JOINT FIT
CLEARANCE
0.2mm TO 0.6mm
POOR FIT
Service Manual
4. Cleaning tubing
To make a sound, leak tight joint, the brazing alloy when raised to
brazing temperature, must wet and flow freely over the entire surface
of the tubing in the joint area.
To assure this, the tubing surfaces must be free of all dirt, grease, oil
and oxides otherwise the alloy will not wet and flow properly over any
surface with these elements present. Cleaning can be done with an
abrasive cloth or steel wool. Never blow into the tubing because this
will introduce a lot of moisture into the system. Open tubing joints
should be covered if exposed for long periods of time.
Cleaning Tubing.
5. Proper fluxing
Flux is necessary when using silver solder; it is not required when
using silfos on copper to copper joints.
To do a good job the flux should cover the tube surface completely. Be
careful not to introduce any flux inside the tubing.
Fluxing should be done after the tubing is mated together and just
before brazing is done. Do not allow it to dry out.
When brazing, the flux should become entirely liquid and clear, like
water. The temperature will be at 1100°F and only a little more heat will
allow the alloy to flow freely into the joint.
Directing Torch Flame to Copper Tubing.
5 – 1
EMERY CLOTH
KEEP TUBE IN
DOWNWARD POSITION
10mm
SILVER ALLOY
INNER CONE
TORCH STEM