Brazing Procedures - Trane SCWM Installation, Operation And Maintenance Manual

W W A A R R N N I I N N G G
E E x x p p l l o o s s i i o o n n H H a a z z a a r r d d ! !
F F a a i i l l u u r r e e t t o o f f o o l l l l o o w w t t h h e e s s e e i i n n s s t t r r u u c c t t i i o o n n s s c c o o u u l l d d r r e e s s u u l l t t i i n n
d d e e a a t t h h o o r r s s e e r r i i o o u u s s i i n n j j u u r r y y o o r r e e q q u u i i p p m m e e n n t t o o r r p p r r o o p p e e r r t t y y - -
o o n n l l y y d d a a m m a a g g e e . .
U U s s e e o o n n l l y y d d r r y y n n i i t t r r o o g g e e n n w w i i t t h h a a p p r r e e s s s s u u r r e e r r e e g g u u l l a a t t o o r r f f o o r r
p p r r e e s s s s u u r r i i z z i i n n g g u u n n i i t t . . D D o o n n o o t t u u s s e e a a c c e e t t y y l l e e n n e e , , o o x x y y g g e e n n o o r r
c c o o m m p p r r e e s s s s e e d d a a i i r r o o r r m m i i x x t t u u r r e e s s c c o o n n t t a a i i n n i i n n g g t t h h e e m m f f o o r r
p p r r e e s s s s u u r r e e t t e e s s t t i i n n g g . . D D o o n n o o t t u u s s e e h h y y d d r r o o g g e e n n m m i i x x t t u u r r e e s s
c c o o n n t t a a i i n n i i n n g g r r e e f f r r i i g g e e r r a a n n t t a a n n d d a a i i r r a a b b o o v v e e a a t t m m o o s s p p h h e e r r i i c c
p p r r e e s s s s u u r r e e f f o o r r p p r r e e s s s s u u r r e e t t e e s s t t i i n n g g a a s s t t h h e e y y m m a a y y b b e e c c o o m m e e
f f l l a a m m m m a a b b l l e e a a n n d d c c o o u u l l d d r r e e s s u u l l t t i i n n a a n n e e x x p p l l o o s s i i o o n n . .
R R e e f f r r i i g g e e r r a a n n t t , , w w h h e e n n u u s s e e d d a a s s a a t t r r a a c c e e g g a a s s s s h h o o u u l l d d o o n n l l y y
b b e e m m i i x x e e d d w w i i t t h h d d r r y y n n i i t t r r o o g g e e n n f f o o r r p p r r e e s s s s u u r r i i z z i i n n g g u u n n i i t t s s . .
W W A A R R N N I I N N G G
E E x x p p l l o o s s i i o o n n H H a a z z a a r r d d ! !
F F a a i i l l u u r r e e t t o o f f o o l l l l o o w w i i n n s s t t r r u u c c t t i i o o n n b b e e l l o o w w c c o o u u l l d d r r e e s s u u l l t t i i n n
d d e e a a t t h h o o r r s s e e r r i i o o u u s s i i n n j j u u r r y y . .
D D o o n n o o t t e e x x c c e e e e d d u u n n i i t t n n a a m m e e p p l l a a t t e e d d e e s s i i g g n n p p r r e e s s s s u u r r e e s s
w w h h e e n n l l e e a a k k t t e e s s t t i i n n g g s s y y s s t t e e m m . .
W W A A R R N N I I N N G G
R R e e f f r r i i g g e e r r a a n n t t u u n n d d e e r r H H i i g g h h P P r r e e s s s s u u r r e e ! !
F F a a i i l l u u r r e e t t o o f f o o l l l l o o w w i i n n s s t t r r u u c c t t i i o o n n s s b b e e l l o o w w c c o o u u l l d d r r e e s s u u l l t t i i n n
a a n n e e x x p p l l o o s s i i o o n n w w h h i i c c h h c c o o u u l l d d r r e e s s u u l l t t i i n n d d e e a a t t h h o o r r
s s e e r r i i o o u u s s i i n n j j u u r r y y o o r r e e q q u u i i p p m m e e n n t t d d a a m m a a g g e e . .
S S y y s s t t e e m m c c o o n n t t a a i i n n s s r r e e f f r r i i g g e e r r a a n n t t u u n n d d e e r r h h i i g g h h p p r r e e s s s s u u r r e e . .
R R e e c c o o v v e e r r r r e e f f r r i i g g e e r r a a n n t t t t o o r r e e l l i i e e v v e e p p r r e e s s s s u u r r e e b b e e f f o o r r e e
o o p p e e n n i i n n g g t t h h e e s s y y s s t t e e m m . . S S e e e e u u n n i i t t n n a a m m e e p p l l a a t t e e f f o o r r
r r e e f f r r i i g g e e r r a a n n t t t t y y p p e e . . D D o o n n o o t t u u s s e e n n o o n n - - a a p p p p r r o o v v e e d d
r r e e f f r r i i g g e e r r a a n n t t s s , , r r e e f f r r i i g g e e r r a a n n t t s s u u b b s s t t i i t t u u t t e e s s , , o o r r r r e e f f r r i i g g e e r r a a n n t t
a a d d d d i i t t i i v v e e s s . .
N N o o t t e e : : These service procedures require working with
refrigerant. Do not release refrigerant to the
atmosphere! The service technician must
comply with all federal, state, and local laws.
When leak-testing refrigerant systems, observe all
safety precautions. Leak test only one circuit at a time
to minimize system exposure to potentially harmful
moisture in the air.
System Repair
1. Connect R-410A refrigerant cylinder to charging
port, add refrigerant to reach pressure of 12 to 15
psig.
2. Disconnect refrigerant cylinder. Connect dry
nitrogen cylinder to high side charging port and
increase pressure to 150 psig. DO NOT exceed unit
nameplate design pressures. If testing complete
system, low side design pressure is maximum.
3. Check piping and/or components as appropriate for
leaks.
4. Recommend using electronic detector capable of
PKG-SVX027C-EN
measuring 0.1 oz/year leak rate.
5. If a leak is located, use proper procedures to
remove the refrigerant/nitrogen mixture, break
connections and make repairs. Retest for leaks.
6. Make sure all service valves are open.

Brazing Procedures

W W A A R R N N I I N N G G
E E x x p p l l o o s s i i o o n n H H a a z z a a r r d d a a n n d d D D e e a a d d l l y y G G a a s s e e s s ! !
F F a a i i l l u u r r e e t t o o f f o o l l l l o o w w a a l l l l p p r r o o p p e e r r s s a a f f e e r r e e f f r r i i g g e e r r a a n n t t
h h a a n n d d l l i i n n g g p p r r a a c c t t i i c c e e s s c c o o u u l l d d r r e e s s u u l l t t i i n n d d e e a a t t h h o o r r s s e e r r i i o o u u s s
i i n n j j u u r r y y . .
N N e e v v e e r r s s o o l l d d e e r r , , b b r r a a z z e e o o r r w w e e l l d d o o n n r r e e f f r r i i g g e e r r a a n n t t l l i i n n e e s s o o r r
a a n n y y u u n n i i t t c c o o m m p p o o n n e e n n t t s s t t h h a a t t a a r r e e a a b b o o v v e e a a t t m m o o s s p p h h e e r r i i c c
p p r r e e s s s s u u r r e e o o r r w w h h e e r r e e r r e e f f r r i i g g e e r r a a n n t t m m a a y y b b e e p p r r e e s s e e n n t t . .
A A l l w w a a y y s s r r e e m m o o v v e e r r e e f f r r i i g g e e r r a a n n t t b b y y f f o o l l l l o o w w i i n n g g t t h h e e
g g u u i i d d e e l l i i n n e e s s e e s s t t a a b b l l i i s s h h e e d d b b y y t t h h e e E E P P A A F F e e d d e e r r a a l l C C l l e e a a n n
A A i i r r A A c c t t o o r r o o t t h h e e r r s s t t a a t t e e o o r r l l o o c c a a l l c c o o d d e e s s a a s s a a p p p p r r o o p p r r i i a a t t e e . .
A A f f t t e e r r r r e e f f r r i i g g e e r r a a n n t t r r e e m m o o v v a a l l , , u u s s e e d d r r y y n n i i t t r r o o g g e e n n t t o o
b b r r i i n n g g s s y y s s t t e e m m b b a a c c k k t t o o a a t t m m o o s s p p h h e e r r i i c c p p r r e e s s s s u u r r e e b b e e f f o o r r e e
o o p p e e n n i i n n g g s s y y s s t t e e m m f f o o r r r r e e p p a a i i r r s s . . M M i i x x t t u u r r e e s s o o f f
r r e e f f r r i i g g e e r r a a n n t t s s a a n n d d a a i i r r u u n n d d e e r r p p r r e e s s s s u u r r e e m m a a y y b b e e c c o o m m e e
c c o o m m b b u u s s t t i i b b l l e e i i n n t t h h e e p p r r e e s s e e n n c c e e o o f f a a n n i i g g n n i i t t i i o o n n s s o o u u r r c c e e
l l e e a a d d i i n n g g t t o o a a n n e e x x p p l l o o s s i i o o n n . . E E x x c c e e s s s s i i v v e e h h e e a a t t f f r r o o m m
s s o o l l d d e e r r i i n n g g , , b b r r a a z z i i n n g g o o r r w w e e l l d d i i n n g g w w i i t t h h r r e e f f r r i i g g e e r r a a n n t t
v v a a p p o o r r s s p p r r e e s s e e n n t t c c a a n n f f o o r r m m h h i i g g h h l l y y t t o o x x i i c c g g a a s s e e s s a a n n d d
e e x x t t r r e e m m e e l l y y c c o o r r r r o o s s i i v v e e a a c c i i d d s s . .
Proper brazing techniques are essential when installing
refrigerant piping. The following factors should be kept
in mind when forming sweat connections:
1. When heating copper in the presence of air, copper
oxide forms. To prevent copper oxide from forming
inside the tubing during brazing, sweep an inert
gas, such as dry nitrogen, through the tubing. A
nitrogen flow of 1 to 3 cubic feet per minute is
sufficient to displace the air in the tubing and
prevent oxidation of the interior surfaces. Use a
pressure regulating valve or flow meter to control
the flow.
2. Ensure that the tubing surfaces requiring brazing
are clean, and that the tube ends are carefully
reamed to remove any burrs.
3. Make sure the inner and outer tubes of the joint are
symmetrical and have a close clearance, providing
an easy "slip" fit. If the joint is too loose, the
connection's tensile strength is significantly
reduced. Ensure the overlap distance is equal to the
inner tube diameter.
4. Wrap each refrigerant line component with a wet
cloth to keep it cool during brazing. Excessive heat
can damage the internal components.
N N o o t t e e : : Use 40-45% silver brazing alloy (BAg-7 or
BAg-28) on dissimilar metals. Use BCup-6
brazing alloy on copper-to-copper joints.
5. If using flux, apply it sparingly to the joint. Excess
M M a a i i n n t t e e n n a a n n c c e e
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